Discussion:
Document with answers to most popular battery-related questions is ready
(too old to reply)
Paul Fertser
2009-08-02 17:07:39 UTC
Permalink
Hi,

This is a text version of the wikipage [1], feel free to ask new questions
there on the talk page. Discussion on this ML is also appreciated (and
in fact i'm more comfortable with ML than the wiki).

Openmoko devices
Battery questions and answers

NB: Some of the described behaviour depends on the kernel, the
relevant code was pushed on 02 Aug to andy-tracking


Hardware capabilities

Q: What batteries can be used with gta01 and gta02?
A: Original OM gta01, gta02, Nokia BL-5C, BL-6C and compatibles.

Q: Do other BL-5/6C compatible batteries fit?
A: If the battery is thicker than BL-6C, you won't be able to close
the back cover.

Q: What is the difference between all those types?
A:

Capacity:
gta01, gta02 - 1200 mAh
BL-5C old (newer/new) - 850 (970/1050) mAh
BL-6C - 1150 mAh

Temperature control:
gta01, BL-5C, BL-6C - thermistor
gta02 - bq27000

Special features:
gta02 - accurate and sophisticated reporting of capacity,
time_to_full, time_to_empty, temperature and battery current during
both charge and discharge thanks to bq27000 (aka Coloumb Counter)

Q: What are hardware capabilities of gta01 and gta02 with regard to
battery management?
A:

gta01: charging all battery types, measuring temperature with
battery-integrated thermistor (currently charging and measuring
temperature for non-gta01 batteries doesn't work due to the kernel
driver issues but it's software limitation), measuring battery output
voltage, very inaccurate and noisy measuring of battery current

gta02: charging all battery types, measuring battery output voltage,
communicating with bq27000

Q: Can nokia phones use/charge gta01/gta02 batteries?
A: gta01 and gta02 batteries will fit wherever BL-6C fits but they
can't be charged in nokia phones unless you isolate the middle pin
from the battery and connect a resistor of ~50k (actual measured value
on a cold (25C) battery is 75k, on a slightly warm battery - 82k) from
it to the ground (to fake a thermistor presence).

Q: Can third-party chargers charge gta01/gta02 batteries?
A: The "good" ones will most probably require the same trick needed
for nokia phones. More cheaper ones are more likely to ignore
thermistor absence.

Q: I have several compatible batteries. What are the storage
requirements for them?
A: Keep in a dry cool place charged to no more than 75%.


Safety issues

Q: Do OM devices control temperature to stop charging if the battery
gets too hot?
A: No (probably gta01 does, need to check).

Q: Isn't it dangerous?
A: No, since all batteries (not raw cells!) have an integrated
protection circuits.

Q: Can i use that fancy 2800 mAh BL-5C-compatible battery i saw on
ebay?
A: Unless you want an explosion in your pocket i wouldn't recommend
using any battery that is not produced by a reputable vendor and
widely tested. And even reputable vendors make mistakes, nokia once
had to recall 46 million batteries manufactured by Matsushita (
http://batteryreplacement.nokia.com/batteryreplacement/en/advisory-2007.html
).

Q: You say that BL-5C is compatible with my gta02. Does that mean i
can use that BL-5C-compatible bat i bought for a buck from a bum?
A: You bet, go ahead.


Charging

Q: My battery charges to 100% but then charging stops and the battery
keeps discharging, wtf?
A: LiIon batteries don't like to be kept fully charged, so the charger
stops as soon as charging current becomes less than threshold. If you
have GSM on it will discharge the battery.

Q: But why doesn't it ever stop charging on my device?
A: The GSM modem is connected directly to the battery terminals so if
it's active, charger will think it's still charging the battery and
won't turn off unless GSM becomes inactive. The default threshold is
about 16mA, the latest Qi increases the threshold to ~32mA.

Q: Does it mean if i leave my phone plugged it will eventually fully
discharge the battery?
A: On gta02 the charger will restart the charge automatically once the
battery voltage reaches ~4V which corresponds to ~76%. Not sure about
gta01, requires more investigation. :-/

Q: Ok, how to make sure my battery is fully charged before a long
trip?
A: Replug the charger, it will trigger charging no matter what the
current capacity is.

Q: My power/aux LED indicates charging/discharging/whatever, what does
that mean (aka why it's still blue even after i unplugged the
charger)?
A: Ask FSO guys about it, some of them think that the user shouldn't
really know what's happening and therefore they do some special
mangling of "status" sysfs node before presenting it to the user. If
you want to make a decent bugreport please add clear steps to
reproduce and /sys/class/power_supply/battery/uevent contents for all
relevant states.


Using compatible batteries with gta02

Q: So, how do i use "dumb" batteries with my freerunner?
A:

First you need to unbind bq27000 driver:
echo bq27000-battery.0 > /sys/bus/platform/drivers/bq27000-battery/unbind

Then you load the dumb battery driver:
modprobe gta01_battery

If you need to use bq27000 driver again, do:
rmmod gta01_battery
echo bq27000-battery.0 > /sys/bus/platform/drivers/bq27000-battery/bind

If you use Enlightment you might need to restart it after that.

Q: Is capacity reported for dumb batteries accurate?
A: During discharge it should be pretty (+-10%) accurate, during
charge the capacity reported is ~20% more than real.

Q: Why does /sys/class/power_supply/battery/charge_full says i have a
850 mAh battery no matter what i use?
A: It's a workaround to make popular battery gadgets work with this
driver.


This Q&A were prepared by
Paul Fertser <***@gmail.com>
Joerg Reisenweber <***@openmoko.org>

[1] http://wiki.openmoko.org/wiki/Battery_Questions_and_Answers
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Wolfgang Spraul
2009-08-02 17:46:26 UTC
Permalink
Paul & Joerg,
this is an excellent document, obviously I cannot spot anything wrong!
I didn't know that some external chargers would not charge gta01 or gta02
batteries because of the thermistor check you are writing about.
All the cheap external chargers we bought in Taiwan or China for testing can
charge both gta01 or gta02 batteries without a problem.

I have a question for all:
We will ship our first NanoNote with a BL-4C compatible battery, without
Coulomb counter (middle pin unused) [1].

How are people really using the Coulomb counter in gta02?
Theoretically I would think that it provides far superior power measurement
options for actual software development, just as you write.
For example when playing with power saving codes, whether in the kernel,
middleware or applications, I would think over the course of several hours or
days the Coulomb counter data is the primary means for efficient development.

So we are considering shipping the next version of the NanoNote with Coulomb
counter batteries same as the Neo FreeRunner.
But if nobody is actually using the data from the Coulomb counter, then it's a
wasted effort.

What do you think?
Was the addition of the Coulomb counter in gta02 really a useful thing?
Did FSO developers or kernel developers use the data for power optimizations?

Thanks,
Wolfgang

[1] http://www.qi-hardware.com/products/ben-nanonote
Post by Paul Fertser
Hi,
This is a text version of the wikipage [1], feel free to ask new questions
there on the talk page. Discussion on this ML is also appreciated (and
in fact i'm more comfortable with ML than the wiki).
Openmoko devices
Battery questions and answers
NB: Some of the described behaviour depends on the kernel, the
relevant code was pushed on 02 Aug to andy-tracking
Hardware capabilities
Q: What batteries can be used with gta01 and gta02?
A: Original OM gta01, gta02, Nokia BL-5C, BL-6C and compatibles.
Q: Do other BL-5/6C compatible batteries fit?
A: If the battery is thicker than BL-6C, you won't be able to close
the back cover.
Q: What is the difference between all those types?
gta01, gta02 - 1200 mAh
BL-5C old (newer/new) - 850 (970/1050) mAh
BL-6C - 1150 mAh
gta01, BL-5C, BL-6C - thermistor
gta02 - bq27000
gta02 - accurate and sophisticated reporting of capacity,
time_to_full, time_to_empty, temperature and battery current during
both charge and discharge thanks to bq27000 (aka Coloumb Counter)
Q: What are hardware capabilities of gta01 and gta02 with regard to
battery management?
gta01: charging all battery types, measuring temperature with
battery-integrated thermistor (currently charging and measuring
temperature for non-gta01 batteries doesn't work due to the kernel
driver issues but it's software limitation), measuring battery output
voltage, very inaccurate and noisy measuring of battery current
gta02: charging all battery types, measuring battery output voltage,
communicating with bq27000
Q: Can nokia phones use/charge gta01/gta02 batteries?
A: gta01 and gta02 batteries will fit wherever BL-6C fits but they
can't be charged in nokia phones unless you isolate the middle pin
from the battery and connect a resistor of ~50k (actual measured value
on a cold (25C) battery is 75k, on a slightly warm battery - 82k) from
it to the ground (to fake a thermistor presence).
Q: Can third-party chargers charge gta01/gta02 batteries?
A: The "good" ones will most probably require the same trick needed
for nokia phones. More cheaper ones are more likely to ignore
thermistor absence.
Q: I have several compatible batteries. What are the storage
requirements for them?
A: Keep in a dry cool place charged to no more than 75%.
Safety issues
Q: Do OM devices control temperature to stop charging if the battery
gets too hot?
A: No (probably gta01 does, need to check).
Q: Isn't it dangerous?
A: No, since all batteries (not raw cells!) have an integrated
protection circuits.
Q: Can i use that fancy 2800 mAh BL-5C-compatible battery i saw on
ebay?
A: Unless you want an explosion in your pocket i wouldn't recommend
using any battery that is not produced by a reputable vendor and
widely tested. And even reputable vendors make mistakes, nokia once
had to recall 46 million batteries manufactured by Matsushita (
http://batteryreplacement.nokia.com/batteryreplacement/en/advisory-2007.html
).
Q: You say that BL-5C is compatible with my gta02. Does that mean i
can use that BL-5C-compatible bat i bought for a buck from a bum?
A: You bet, go ahead.
Charging
Q: My battery charges to 100% but then charging stops and the battery
keeps discharging, wtf?
A: LiIon batteries don't like to be kept fully charged, so the charger
stops as soon as charging current becomes less than threshold. If you
have GSM on it will discharge the battery.
Q: But why doesn't it ever stop charging on my device?
A: The GSM modem is connected directly to the battery terminals so if
it's active, charger will think it's still charging the battery and
won't turn off unless GSM becomes inactive. The default threshold is
about 16mA, the latest Qi increases the threshold to ~32mA.
Q: Does it mean if i leave my phone plugged it will eventually fully
discharge the battery?
A: On gta02 the charger will restart the charge automatically once the
battery voltage reaches ~4V which corresponds to ~76%. Not sure about
gta01, requires more investigation. :-/
Q: Ok, how to make sure my battery is fully charged before a long
trip?
A: Replug the charger, it will trigger charging no matter what the
current capacity is.
Q: My power/aux LED indicates charging/discharging/whatever, what does
that mean (aka why it's still blue even after i unplugged the
charger)?
A: Ask FSO guys about it, some of them think that the user shouldn't
really know what's happening and therefore they do some special
mangling of "status" sysfs node before presenting it to the user. If
you want to make a decent bugreport please add clear steps to
reproduce and /sys/class/power_supply/battery/uevent contents for all
relevant states.
Using compatible batteries with gta02
Q: So, how do i use "dumb" batteries with my freerunner?
echo bq27000-battery.0 > /sys/bus/platform/drivers/bq27000-battery/unbind
modprobe gta01_battery
rmmod gta01_battery
echo bq27000-battery.0 > /sys/bus/platform/drivers/bq27000-battery/bind
If you use Enlightment you might need to restart it after that.
Q: Is capacity reported for dumb batteries accurate?
A: During discharge it should be pretty (+-10%) accurate, during
charge the capacity reported is ~20% more than real.
Q: Why does /sys/class/power_supply/battery/charge_full says i have a
850 mAh battery no matter what i use?
A: It's a workaround to make popular battery gadgets work with this
driver.
This Q&A were prepared by
[1] http://wiki.openmoko.org/wiki/Battery_Questions_and_Answers
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
_______________________________________________
Openmoko community mailing list
http://lists.openmoko.org/mailman/listinfo/community
Paul Fertser
2009-08-02 18:02:42 UTC
Permalink
Post by Wolfgang Spraul
this is an excellent document, obviously I cannot spot anything wrong!
Thanks for you kind words. :)
Post by Wolfgang Spraul
I didn't know that some external chargers would not charge gta01 or gta02
batteries because of the thermistor check you are writing about.
I'm not sure i saw any charger like that myself or seen reports
(except on our wiki). But i suspect the probability of that for nokia
brand charges is quite high.
Post by Wolfgang Spraul
All the cheap external chargers we bought in Taiwan or China for testing can
charge both gta01 or gta02 batteries without a problem.
Proves my point :D
Post by Wolfgang Spraul
We will ship our first NanoNote with a BL-4C compatible battery, without
Coulomb counter (middle pin unused) [1].
Hm, can BL-5C fit there? Because it'd be much nicer as modern 5Cs have
quite some capacity.
Post by Wolfgang Spraul
How are people really using the Coulomb counter in gta02?
Theoretically I would think that it provides far superior power measurement
options for actual software development, just as you write.
For example when playing with power saving codes, whether in the kernel,
middleware or applications, I would think over the course of several hours or
days the Coulomb counter data is the primary means for efficient development.
To me it seems that CC readings are almost unused except for
presenting the user with a bit more accurate capacity data. And when
someone is developing something lowlevel he could as well connect and
external ampmeter, much more reliable and flexible approach.
Post by Wolfgang Spraul
So we are considering shipping the next version of the NanoNote with Coulomb
counter batteries same as the Neo FreeRunner.
But if nobody is actually using the data from the Coulomb counter, then it's a
wasted effort.
I'm not sure you'll get much for using CC.

The only problem so far with using a dumb battery on FR is that
there's no way to know the current from inside the device. On gta01
there's a resistor shunt supposed to be used to measure the current
but readings are too noisy to be useable. So if you have a good way to
measure current already i'd not go for CC.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Wolfgang Spraul
2009-08-02 18:27:58 UTC
Permalink
Paul,
Post by Paul Fertser
Post by Wolfgang Spraul
We will ship our first NanoNote with a BL-4C compatible battery, without
Coulomb counter (middle pin unused) [1].
Hm, can BL-5C fit there? Because it'd be much nicer as modern 5Cs have
quite some capacity.
It fits, but it's a bit too thick so it's hard to close the battery cover with
a BL-5C (or gta02 battery) inside. Not recommended.
Post by Paul Fertser
The only problem so far with using a dumb battery on FR is that
there's no way to know the current from inside the device. On gta01
there's a resistor shunt supposed to be used to measure the current
but readings are too noisy to be useable. So if you have a good way to
measure current already i'd not go for CC.
Hmm, that's a pretty strong statement.
At Openmoko we spent _a lot_ of money combined to get this CC thing to work.
The theory was that you have it in most notebook batteries so it's 'a good
thing to have'.
But if it's not actually used, then it would be one of those many things
we did that should have been better thought through.

I will check with Adam about precise current measurements for the NanoNote,
and still I would appreciate any feedback from other people who are using the
CC data for something other than proving that we have it :-)

Any Coulomb fans out there?

Wolfgang
Post by Paul Fertser
Post by Wolfgang Spraul
this is an excellent document, obviously I cannot spot anything wrong!
Thanks for you kind words. :)
Post by Wolfgang Spraul
I didn't know that some external chargers would not charge gta01 or gta02
batteries because of the thermistor check you are writing about.
I'm not sure i saw any charger like that myself or seen reports
(except on our wiki). But i suspect the probability of that for nokia
brand charges is quite high.
Post by Wolfgang Spraul
All the cheap external chargers we bought in Taiwan or China for testing can
charge both gta01 or gta02 batteries without a problem.
Proves my point :D
Post by Wolfgang Spraul
We will ship our first NanoNote with a BL-4C compatible battery, without
Coulomb counter (middle pin unused) [1].
Hm, can BL-5C fit there? Because it'd be much nicer as modern 5Cs have
quite some capacity.
Post by Wolfgang Spraul
How are people really using the Coulomb counter in gta02?
Theoretically I would think that it provides far superior power measurement
options for actual software development, just as you write.
For example when playing with power saving codes, whether in the kernel,
middleware or applications, I would think over the course of several hours or
days the Coulomb counter data is the primary means for efficient development.
To me it seems that CC readings are almost unused except for
presenting the user with a bit more accurate capacity data. And when
someone is developing something lowlevel he could as well connect and
external ampmeter, much more reliable and flexible approach.
Post by Wolfgang Spraul
So we are considering shipping the next version of the NanoNote with Coulomb
counter batteries same as the Neo FreeRunner.
But if nobody is actually using the data from the Coulomb counter, then it's a
wasted effort.
I'm not sure you'll get much for using CC.
The only problem so far with using a dumb battery on FR is that
there's no way to know the current from inside the device. On gta01
there's a resistor shunt supposed to be used to measure the current
but readings are too noisy to be useable. So if you have a good way to
measure current already i'd not go for CC.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
Paul Fertser
2009-08-02 18:34:48 UTC
Permalink
Post by Wolfgang Spraul
Post by Paul Fertser
Post by Wolfgang Spraul
We will ship our first NanoNote with a BL-4C compatible battery, without
Coulomb counter (middle pin unused) [1].
Hm, can BL-5C fit there? Because it'd be much nicer as modern 5Cs have
quite some capacity.
It fits, but it's a bit too thick so it's hard to close the battery cover with
a BL-5C (or gta02 battery) inside. Not recommended.
gta02 battery is really thicker (~1mm) than BL-5C. It's BL-6C that is
the same thickness as gta02 battery.
Post by Wolfgang Spraul
Post by Paul Fertser
The only problem so far with using a dumb battery on FR is that
there's no way to know the current from inside the device. On gta01
there's a resistor shunt supposed to be used to measure the current
but readings are too noisy to be useable. So if you have a good way to
measure current already i'd not go for CC.
Hmm, that's a pretty strong statement.
At Openmoko we spent _a lot_ of money combined to get this CC thing to work.
The theory was that you have it in most notebook batteries so it's 'a good
thing to have'.
You know, my notebook (Acer travelmate) has those advanced battery
readings. But it didn't help it to not fuck up my battery completely
while i constantly kept it connected to AC. The charging is not kernel
controlled (probably there're some ACPI functions for that but who
knows that shit...).

So for me what matters is not advanced metering, for me it's proper
battery charging management, i want my battery to last long.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Michal Brzozowski
2009-08-02 18:58:08 UTC
Permalink
Post by Wolfgang Spraul
Hmm, that's a pretty strong statement.
At Openmoko we spent _a lot_ of money combined to get this CC thing to work.
The theory was that you have it in most notebook batteries so it's 'a good
thing to have'.
But if it's not actually used, then it would be one of those many things
we did that should have been better thought through.
No, I think it was a very good decision. Not only low-level programmers need
it, but also normal* users who want to know how long the battery lasts with
certain configurations. I know for example that with gsm on it lasts about
50h in suspend, with gsm off about 100h, and with gps on about 8h without
suspend, etc. And I could estimate this accurately overnight, and not by
waiting 4 days.

On the other hand, I have absolutely no idea how long my motorola battery
lasts. It usually shows full for a few days and then drops really quickly.

*if you can call FR users normal users
Paul Fertser
2009-08-02 19:05:18 UTC
Permalink
Post by Wolfgang Spraul
Hmm, that's a pretty strong statement.
At Openmoko we spent _a lot_ of money combined to get this CC thing to work.
The theory was that you have it in most notebook batteries so it's 'a good
thing to have'.
But if it's not actually used, then it would be one of those many things
we did that should have been better thought through.
No, I think it was a very good decision. Not only low-level
programmers need it, but also normal* users who want to know how
long the battery lasts with certain configurations. I know for
example that with gsm on it lasts about 50h in suspend, with gsm off
about 100h
Hm, there's probably something very wrong with your config, no?

With GSM on in suspend it should last for 140 hrs and with off it
should be even more.

Hm, so basically your point is that CC allows current measurement in
suspend. Ok, but if there're convenient TPs you can use your DMM to do
the same as well. Also you can do that by connecting the device via
DMM to a lab PSU or a pack of AA batteries. Moreover, there's quite a
limited number of usecases (wrt power-management) so those who has
some EE skills can do the measurements once and then share the info
for everybody.

Wolfgang, please consider making current measurement in suspend
easy. :)
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
arne anka
2009-08-02 19:14:00 UTC
Permalink
Post by Paul Fertser
Hm, there's probably something very wrong with your config, no?
what config?
Post by Paul Fertser
With GSM on in suspend it should last for 140 hrs
only when deep sleep is usable.
the only time i ever heard of 140h suspend were the mail from daniel
willmann after he applied a hw fix to #1024.
my fr suffers from #1024 and thus has to be set deep sleep never -- which
means about 50hrs in suspend.
with deep sleep adaptive it works up all the time, which means a suspend
time far less.
Paul Fertser
2009-08-02 19:17:48 UTC
Permalink
Post by arne anka
Post by Paul Fertser
Hm, there's probably something very wrong with your config, no?
what config?
Probably deep sleep disabled :)
Post by arne anka
Post by Paul Fertser
With GSM on in suspend it should last for 140 hrs
only when deep sleep is usable.
Sure. And with deep sleep disabled it should still be ~70hrs, there're
some logs from Mickey proving that.
Post by arne anka
the only time i ever heard of 140h suspend were the mail from daniel
willmann after he applied a hw fix to #1024.
Yes, exactly. But fixing is fairly trivial, the soldering part is in
fact easier than the buzz fix.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
arne anka
2009-08-02 19:23:04 UTC
Permalink
Post by Paul Fertser
Yes, exactly. But fixing is fairly trivial, the soldering part is in
fact easier than the buzz fix.
well, i sincerely hop, someone steps up and offers that kind of fix.
Michal Brzozowski
2009-08-02 19:38:09 UTC
Permalink
Post by Paul Fertser
Sure. And with deep sleep disabled it should still be ~70hrs, there're
some logs from Mickey proving that.
Oh, interesting. Maybe it was on a pure console image? I tested this some
time ago and I think that running X + enlightenment used more power on
suspend, although it doesn't make sense to me. Anyway, I'm quite sure that a
fresh SHR install with gsm on won't go for more than 50h in suspend on my
phone.
Post by Paul Fertser
Post by arne anka
the only time i ever heard of 140h suspend were the mail from daniel
willmann after he applied a hw fix to #1024.
Yes, exactly. But fixing is fairly trivial, the soldering part is in
fact easier than the buzz fix.
When will 'normal' users be able to send in their phones to get this done?
Paul Fertser
2009-08-02 19:51:54 UTC
Permalink
Post by Paul Fertser
Sure. And with deep sleep disabled it should still be ~70hrs, there're
some logs from Mickey proving that.
Oh, interesting. Maybe it was on a pure console image? I tested this
some time ago and I think that running X + enlightenment used more
power on suspend, although it doesn't make sense to me. Anyway, I'm
quite sure that a fresh SHR install with gsm on won't go for more
than 50h in suspend on my phone.
Strange, needs investigations...
Post by Paul Fertser
Post by arne anka
the only time i ever heard of 140h suspend were the mail from daniel
willmann after he applied a hw fix to #1024.
Yes, exactly. But fixing is fairly trivial, the soldering part is in
fact easier than the buzz fix.
When will 'normal' users be able to send in their phones to get this done?
Is Poland _that_ different from Russia? Here we have plenty of places
where you can repair electronic equipment. Those guys have no
difficulties desoldering and soldering a huge ;) (0805) cap. And quite
acceptable prices too. Man, they do BGA rework, one 0805 part can't be
hard for them!
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Rask Ingemann Lambertsen
2009-08-09 00:16:39 UTC
Permalink
Post by Paul Fertser
Post by arne anka
the only time i ever heard of 140h suspend were the mail from daniel
willmann after he applied a hw fix to #1024.
Yes, exactly. But fixing is fairly trivial, the soldering part is in
fact easier than the buzz fix.
Yes, the soldering part. So you "only" have the remaining parts to do:

1) Find somewhere to buy a 10 uF SMD capacitor small enough. E.g. there's
nowhere in Denmark I can get one. I'd need to go abroad (Malmö, Sweden)[1]
for a shop that sells a 0805 16 V one to hobbyists or, as I'll do in this
case, buy 20 0805 22 uF ones from Digikey, of which 18 will be used
for the bass fix, one for #1024 and one for fun and games[2].

2) Disassemble the Neo not doing any damage.
3) Take the can off in such a shape as to be able to put it on again.

5) Put the can back on in a reasonably good shape.
6) Assemble the Neo.

And the thing is, if you don't already have a soldering iron and can't
borrow one (including someone to operate it?) then part 4) isn't really all
that trivial either. Unless someone sets up a #1024 fix programme, like
there was the buzz fix programme, the #1024 fix will likely be out of reach
to most of those affected.

So the lady looked at the riot from the comfort of her castle.
"Why is the crowd so angry?" she asked.
"They have no money to buy bread, mylady" she was explained.
"Can't they just eat cookies?" she asked.

These days, you're less likely to be punished by hanging for such
behaviour. But I think you should still not assume that every Neo owner has
access to the #1024 GSM fix necessary for the 140 hour standby time.

[1] http://www.electrokit.se/
[2] If I had an A5, I'd give it a shot to make it start without a battery.
--
Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year
arne anka
2009-08-10 11:41:49 UTC
Permalink
Post by Rask Ingemann Lambertsen
1) Find somewhere to buy a 10 uF SMD capacitor small enough. E.g. there's
nowhere in Denmark I can get one. I'd need to go abroad (Malmö, Sweden)[1]
i assume, you are located at sjælland, then?
any chance you'd be willing to apply that fix to othere people's frerunner?
i'd gladly consider a trip to copenhagen or roskilde ...
Rask Ingemann Lambertsen
2009-08-15 12:44:25 UTC
Permalink
Post by arne anka
Post by Rask Ingemann Lambertsen
1) Find somewhere to buy a 10 uF SMD capacitor small enough. E.g. there's
nowhere in Denmark I can get one. I'd need to go abroad (Malmö, Sweden)[1]
i assume, you are located at sjælland, then?
Yes.
Post by arne anka
any chance you'd be willing to apply that fix to othere people's frerunner?
i'd gladly consider a trip to copenhagen or roskilde ...
No promises until I've applied the #1024 fix to my own Freerunner.
--
Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year
Paul Fertser
2009-08-10 11:51:59 UTC
Permalink
Post by Rask Ingemann Lambertsen
Post by Paul Fertser
Post by arne anka
the only time i ever heard of 140h suspend were the mail from daniel
willmann after he applied a hw fix to #1024.
Yes, exactly. But fixing is fairly trivial, the soldering part is in
fact easier than the buzz fix.
1) Find somewhere to buy a 10 uF SMD capacitor small enough. E.g. there's
nowhere in Denmark I can get one. I'd need to go abroad (Malmö, Sweden)[1]
for a shop that sells a 0805 16 V one to hobbyists or, as I'll do in this
case, buy 20 0805 22 uF ones from Digikey, of which 18 will be used
for the bass fix, one for #1024 and one for fun and games[2].
I admit it's easier to source the cap being in Moscow, here you just
go to a shop and buy as many as you need. But even if one can't go to
a shop himself he can ask a buddy to get the caps and send by snail
mail. I can't see how it's can make a real problem.
Post by Rask Ingemann Lambertsen
2) Disassemble the Neo not doing any damage.
Trivial, wiki instructions are very clear, and plastic clips are
durable enough. I did it the day i bought my FR without fear or
issues.
Post by Rask Ingemann Lambertsen
3) Take the can off in such a shape as to be able to put it on
again.
Well, i did it myself during F9N (not exactly comfortable conditions!)
with a usual knife i borrowed from Daniel. Did no damage. That was the
first time i opened the GSM can. Requires a bit of patience, otherwise
trivial.
Post by Rask Ingemann Lambertsen
5) Put the can back on in a reasonably good shape.
6) Assemble the Neo.
Both are non-issues for any man who's not disabled.
Post by Rask Ingemann Lambertsen
And the thing is, if you don't already have a soldering iron and can't
borrow one (including someone to operate it?) then part 4) isn't really all
that trivial either.
Having seen so many cool hardware projects/tricks/hacking devices/DIY
mods from European folks i really doubt it's that hard to find a guy
who can solder modern components somewhere nearby. Aren't there any
projects in universities that require soldering? So there're people
who know how to do it.
Post by Rask Ingemann Lambertsen
Unless someone sets up a #1024 fix programme, like there was the
buzz fix programme, the #1024 fix will likely be out of reach to
most of those affected.
Rask, with all my respect i still can't see what makes it
prohibitively hard for most of FR users to actually implement #1024
fix.

Sometimes i'm told i'm leaving in a parallel universe. Well, that's
quite possible indeed.
Post by Rask Ingemann Lambertsen
These days, you're less likely to be punished by hanging for such
behaviour.
I do not exactly like the analogy :-/
Post by Rask Ingemann Lambertsen
But I think you should still not assume that every Neo owner has
access to the #1024 GSM fix necessary for the 140 hour standby time.
Should i also refrain from assuming every Neo owner has access to some
*nix box? Or to ssh client? This might make sense _if_ Neo wasn't a
geek/hacker/developer device. But it is so its users are supposed to
be able to solve small riddles along their ways to freedom.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Mikhail Umorin
2009-08-10 19:27:55 UTC
Permalink
Post by Paul Fertser
Post by Rask Ingemann Lambertsen
But I think you should still not assume that every Neo owner has
access to the #1024 GSM fix necessary for the 140 hour standby time.
Should i also refrain from assuming every Neo owner has access to some
*nix box? Or to ssh client? This might make sense _if_ Neo wasn't a
geek/hacker/developer device. But it is so its users are supposed to
be able to solve small riddles along their ways to freedom.
Paul, I think you are missing the risk part of it: if I screw up in software I
can just reflash the device if I break a tiny piece of hardware -- my $400 fr
is gone.

Software and hardware are two totally different animals and being a geek in
one does not imply being a geek in the other.

I don't feel comfortable with any hw work exactly because of the risks
involved. So, I would like some else fix this hw bug, but not just a guy
around the corner -- I want a high degree of certainty that I shall get back a
working device.

Mikhail.
Paul Fertser
2009-08-10 22:22:12 UTC
Permalink
Post by Mikhail Umorin
Post by Paul Fertser
Post by Rask Ingemann Lambertsen
But I think you should still not assume that every Neo owner has
access to the #1024 GSM fix necessary for the 140 hour standby time.
Should i also refrain from assuming every Neo owner has access to some
*nix box? Or to ssh client? This might make sense _if_ Neo wasn't a
geek/hacker/developer device. But it is so its users are supposed to
be able to solve small riddles along their ways to freedom.
Paul, I think you are missing the risk part of it: if I screw up in software I
can just reflash the device if I break a tiny piece of hardware -- my $400 fr
is gone.
I'm somehow certain that's a wrong assumption. Unless you do something
really cruel you're not likely to foobar the whole device. Also even
some fatal mistake will cost you less than $400 because the prices
really dropped lately.
Post by Mikhail Umorin
Software and hardware are two totally different animals and being a geek in
one does not imply being a geek in the other.
Being a geek is a way of life, that's how i see it.
Post by Mikhail Umorin
I don't feel comfortable with any hw work exactly because of the risks
involved. So, I would like some else fix this hw bug, but not just a guy
around the corner -- I want a high degree of certainty that I shall get back a
working device.
Well, i had a talk with cell phone repair guy today. Showed him my FR
with front case dismounted so he could see how much work is involved
in doing the buzz-fix. He said the work itself is very-very easy and
he'd charge $30 or probably $15 if he liked the client.

Probably you just can't imagine what cell phone repair guys usually
do, comparing to that buzzfixing is really easy.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Mikhail Umorin
2009-08-11 01:47:01 UTC
Permalink
Post by Paul Fertser
Post by Mikhail Umorin
Post by Paul Fertser
Post by Rask Ingemann Lambertsen
But I think you should still not assume that every Neo owner has
access to the #1024 GSM fix necessary for the 140 hour standby time.
Should i also refrain from assuming every Neo owner has access to some
*nix box? Or to ssh client? This might make sense _if_ Neo wasn't a
geek/hacker/developer device. But it is so its users are supposed to
be able to solve small riddles along their ways to freedom.
Paul, I think you are missing the risk part of it: if I screw up in
software I can just reflash the device if I break a tiny piece of
hardware -- my $400 fr is gone.
I'm somehow certain that's a wrong assumption. Unless you do something
really cruel you're not likely to foobar the whole device. Also even
some fatal mistake will cost you less than $400 because the prices
really dropped lately.
Post by Mikhail Umorin
Software and hardware are two totally different animals and being a geek
in one does not imply being a geek in the other.
Being a geek is a way of life, that's how i see it.
Post by Mikhail Umorin
I don't feel comfortable with any hw work exactly because of the risks
involved. So, I would like some else fix this hw bug, but not just a guy
around the corner -- I want a high degree of certainty that I shall get
back a working device.
Well, i had a talk with cell phone repair guy today. Showed him my FR
with front case dismounted so he could see how much work is involved
in doing the buzz-fix. He said the work itself is very-very easy and
he'd charge $30 or probably $15 if he liked the client.
Probably you just can't imagine what cell phone repair guys usually
do, comparing to that buzzfixing is really easy.
Ok, maybe I'll give it a try (i.e. ask some one else to do it) :-)
What's a good website to get the required cap (and what cap, brand, product
#)?
Mikhail Umorin
2009-08-11 03:06:38 UTC
Permalink
BTW...

is this bug fixed in A7?
Mikhail Umorin
2009-08-12 00:31:59 UTC
Permalink
Post by Mikhail Umorin
Ok, maybe I'll give it a try (i.e. ask some one else to do it) :-)
What's a good website to get the required cap (and what cap, brand,
product #)?
What you need is 0805 ceramic capacitor, 22uF, 6.3V (or more).
http://chipdip.ru/product0/276924954.aspx
This was bought and used successfully by Q-Master.
HTH
Thank you for the info, Paul. Thanks also for the hint about digikey.com as
the source for those caps in the US.
Michal Brzozowski
2009-08-11 08:35:27 UTC
Permalink
Post by Mikhail Umorin
Post by Mikhail Umorin
Post by Paul Fertser
Post by Rask Ingemann Lambertsen
But I think you should still not assume that every Neo owner has
access to the #1024 GSM fix necessary for the 140 hour standby time.
Should i also refrain from assuming every Neo owner has access to some
*nix box? Or to ssh client? This might make sense _if_ Neo wasn't a
geek/hacker/developer device. But it is so its users are supposed to
be able to solve small riddles along their ways to freedom.
Paul, I think you are missing the risk part of it: if I screw up in
software I
Post by Mikhail Umorin
can just reflash the device if I break a tiny piece of hardware -- my
$400 fr
Post by Mikhail Umorin
is gone.
I'm somehow certain that's a wrong assumption. Unless you do something
really cruel you're not likely to foobar the whole device. Also even
some fatal mistake will cost you less than $400 because the prices
really dropped lately.
I think I've read an email on this group from someone who broke their LCD by
trying to do the #1024 fix. The geek inside me will gladly wait for one of
the resellers to offer the fix.
Paul Fertser
2009-08-11 08:51:10 UTC
Permalink
Post by Paul Fertser
Post by Mikhail Umorin
Paul, I think you are missing the risk part of it: if I screw up in software I
can just reflash the device if I break a tiny piece of hardware -- my $400 fr
is gone.
I'm somehow certain that's a wrong assumption. Unless you do something
really cruel you're not likely to foobar the whole device. Also even
some fatal mistake will cost you less than $400 because the prices
really dropped lately.
I think I've read an email on this group from someone who broke
their LCD by trying to do the # 1024 fix. The geek inside me will
gladly wait for one of the resellers to offer the fix.
IIRC it was a buzzfix attempt. Doing #1024 is safer for the LCM (as
you put the device LCM down and solder on the opposite side of the
pcb). Also, even a new LCM bought from one of the resellers doesn't
cost $400.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Rask Ingemann Lambertsen
2009-08-14 10:05:19 UTC
Permalink
Post by Paul Fertser
Post by Rask Ingemann Lambertsen
1) Find somewhere to buy a 10 uF SMD capacitor small enough. E.g. there's
nowhere in Denmark I can get one. I'd need to go abroad (Malmö, Sweden)[1]
for a shop that sells a 0805 16 V one to hobbyists or, as I'll do in this
case, buy 20 0805 22 uF ones from Digikey, of which 18 will be used
for the bass fix, one for #1024 and one for fun and games[2].
I admit it's easier to source the cap being in Moscow, here you just
go to a shop and buy as many as you need. But even if one can't go to
a shop himself he can ask a buddy to get the caps and send by snail
mail. I can't see how it's can make a real problem.
This means you need to find a buddy who can get the caps. I think it's
just a lot easier to find components in your part of the world. For example,
while looking for a VS6724Q0FB camera module, I've come across no less than
four russian webshops[1] that seem to offer it. In contrast, the only three
places that turn up in Europe are distributors that only sell to businesses
and organisations[2].

[1] http://www.radel.ru/items_128989.htm
http://www.prom-electro.ru/index.php?categoryID=13+99+2
http://www.cec-mc.ru/icatalog/view/377595.html
http://www.imek.su/66500/item66295.html
[2] http://www.eurotech.co.uk/components/1523.html
http://www.rutronik.com/
http://www.baselectronic.com/stocklist.html
Post by Paul Fertser
Post by Rask Ingemann Lambertsen
2) Disassemble the Neo not doing any damage.
Trivial, wiki instructions are very clear, and plastic clips are
durable enough. I did it the day i bought my FR without fear or
issues.
No, you need to apply a lot more force than I'm comfortable with for a
device that I want to keep in a usable condition. As it turns out, it works
out fine, but that's not obvious from the beginning. But yes, maybe we just
need to make a video of someone doing it. For example, I would be most
interested in seeing Jörg Reisenweber's one-hand trick with the PCB.
Post by Paul Fertser
Post by Rask Ingemann Lambertsen
5) Put the can back on in a reasonably good shape.
6) Assemble the Neo.
Both are non-issues for any man who's not disabled.
I withdraw 5) and 6). If you've gone so far as to take the Neo apart in
the first place, reassembling it will be a non-issue.
Post by Paul Fertser
Having seen so many cool hardware projects/tricks/hacking devices/DIY
mods from European folks i really doubt it's that hard to find a guy
who can solder modern components somewhere nearby. Aren't there any
projects in universities that require soldering? So there're people
who know how to do it.
I, for one, wouldn't really know where to look if I couldn't solder
myself.
Post by Paul Fertser
Sometimes i'm told i'm leaving in a parallel universe. Well, that's
quite possible indeed.
And a much better universe too. Where did you find that wormhole? :-)
--
Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year
Wolfgang Spraul
2009-08-02 19:18:46 UTC
Permalink
Paul,
Post by Paul Fertser
Wolfgang, please consider making current measurement in suspend
easy. :)
Yeah - I thought that's what we were talking about :-)
I'm not sure about your TP/DMM/EE advice.

Isn't the Coulomb counter the perfect way to make precise data available to
everybody? That was the point I was trying to get to.
If not CC, what are the alternatives? Test points don't sound right to me.
Precise current measurements maybe, but only if they are precise enough and
can really serve the same purpose as the CC.

Wolfgang
Post by Paul Fertser
Post by Wolfgang Spraul
Hmm, that's a pretty strong statement.
At Openmoko we spent _a lot_ of money combined to get this CC thing to work.
The theory was that you have it in most notebook batteries so it's 'a good
thing to have'.
But if it's not actually used, then it would be one of those many things
we did that should have been better thought through.
No, I think it was a very good decision. Not only low-level
programmers need it, but also normal* users who want to know how
long the battery lasts with certain configurations. I know for
example that with gsm on it lasts about 50h in suspend, with gsm off
about 100h
Hm, there's probably something very wrong with your config, no?
With GSM on in suspend it should last for 140 hrs and with off it
should be even more.
Hm, so basically your point is that CC allows current measurement in
suspend. Ok, but if there're convenient TPs you can use your DMM to do
the same as well. Also you can do that by connecting the device via
DMM to a lab PSU or a pack of AA batteries. Moreover, there's quite a
limited number of usecases (wrt power-management) so those who has
some EE skills can do the measurements once and then share the info
for everybody.
Wolfgang, please consider making current measurement in suspend
easy. :)
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
_______________________________________________
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http://lists.openmoko.org/mailman/listinfo/community
Paul Fertser
2009-08-02 19:30:45 UTC
Permalink
Post by Wolfgang Spraul
Post by Paul Fertser
Wolfgang, please consider making current measurement in suspend
easy. :)
Yeah - I thought that's what we were talking about :-)
I'm not sure about your TP/DMM/EE advice.
Hm, if the TPs are easily reachable i'd say that measuring voltage
over them is fairly easy. I don't think the guys working on suspend
consumption issues would need more. Also the kind of battery
receptable for BL-5C is very convenient to hook up an external PSU to
(even without soldering) so that's not really a problem as well.
Post by Wolfgang Spraul
Isn't the Coulomb counter the perfect way to make precise data available to
everybody? That was the point I was trying to get to.
The question is if in fact everybody needs precise data. Gta02 shows
that's not the case, at least that's how i see it. Both for end-users
and for app developer. And for me personally battery accessibility (i
can go to the nearest shop and buy a BL-6C in no time and for a fairly
low price) is far more important than accurate readings.

So let's wait and see what other folks say.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Wolfgang Spraul
2009-08-02 19:37:53 UTC
Permalink
Paul,
And for me personally battery accessibility (i can go to the nearest shop
and buy a BL-6C in no time and for a fairly low price) is far more
important than accurate readings.
Oh sure, totally agree with you.
The question for me is only whether the device should support the 3rd pin
on the battery connector.
One could imagine that the device normally ships with regular (non-CC)
batteries, but a SW developer interested in power consumption could use a CC
battery. Hey, for the NanoNotes we wouldn't even need to make special batteries
because the gat02 batteries fit, at least for development purposes (the
battery cover doesn't really fit anymore as I said).

So we could ship the device with the 3rd pin wired up, but without a CC battery
in the package. The CC battery would be the tool of choice for power
consumption work.

Like you said, let's see whether someone else speaks up...
Thanks for all your feedback so far,
Wolfgang
Post by Wolfgang Spraul
Post by Paul Fertser
Wolfgang, please consider making current measurement in suspend
easy. :)
Yeah - I thought that's what we were talking about :-)
I'm not sure about your TP/DMM/EE advice.
Hm, if the TPs are easily reachable i'd say that measuring voltage
over them is fairly easy. I don't think the guys working on suspend
consumption issues would need more. Also the kind of battery
receptable for BL-5C is very convenient to hook up an external PSU to
(even without soldering) so that's not really a problem as well.
Post by Wolfgang Spraul
Isn't the Coulomb counter the perfect way to make precise data available to
everybody? That was the point I was trying to get to.
The question is if in fact everybody needs precise data. Gta02 shows
that's not the case, at least that's how i see it. Both for end-users
and for app developer. And for me personally battery accessibility (i
can go to the nearest shop and buy a BL-6C in no time and for a fairly
low price) is far more important than accurate readings.
So let's wait and see what other folks say.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
Michal Brzozowski
2009-08-02 19:20:39 UTC
Permalink
Post by Wolfgang Spraul
Post by Wolfgang Spraul
Hmm, that's a pretty strong statement.
At Openmoko we spent _a lot_ of money combined to get this CC thing
to work.
Post by Wolfgang Spraul
The theory was that you have it in most notebook batteries so it's 'a
good
Post by Wolfgang Spraul
thing to have'.
But if it's not actually used, then it would be one of those many
things
Post by Wolfgang Spraul
we did that should have been better thought through.
No, I think it was a very good decision. Not only low-level
programmers need it, but also normal* users who want to know how
long the battery lasts with certain configurations. I know for
example that with gsm on it lasts about 50h in suspend, with gsm off
about 100h
Hm, there's probably something very wrong with your config, no?
With GSM on in suspend it should last for 140 hrs and with off it
should be even more.
Really? Isn't that with deep sleep on?
Post by Wolfgang Spraul
Hm, so basically your point is that CC allows current measurement in
suspend. Ok, but if there're convenient TPs you can use your DMM to do
the same as well. Also you can do that by connecting the device via
DMM to a lab PSU or a pack of AA batteries. Moreover, there's quite a
limited number of usecases (wrt power-management) so those who has
some EE skills can do the measurements once and then share the info
for everybody.
Paul, of all those acronyms I only understand AA batteries. I said I'm a
normal user :-)
Paul Fertser
2009-08-02 19:23:36 UTC
Permalink
Post by Paul Fertser
With GSM on in suspend it should last for 140 hrs and with off it
should be even more.
Really? Isn't that with deep sleep on?
Sure.
Post by Paul Fertser
Paul, of all those acronyms I only understand AA batteries. I said
I'm a normal user :-)
ROTFL
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Rask Ingemann Lambertsen
2009-08-09 01:40:29 UTC
Permalink
Post by Michal Brzozowski
Post by Paul Fertser
With GSM on in suspend it should last for 140 hrs and with off it
should be even more.
Really? Isn't that with deep sleep on?
Yes. With GSM off, approximately 8 mA is drawn and the battery should
last for something like 150 hours from fully charged battery when new.
Post by Michal Brzozowski
Post by Paul Fertser
Hm, so basically your point is that CC allows current measurement in
suspend. Ok, but if there're convenient TPs you can use your DMM to do
the same as well. Also you can do that by connecting the device via
DMM to a lab PSU or a pack of AA batteries. Moreover, there's quite a
limited number of usecases (wrt power-management) so those who has
some EE skills can do the measurements once and then share the info
for everybody.
Paul, of all those acronyms I only understand AA batteries. I said I'm a
normal user :-)
CC = Coulumb counter. Measures the flow of charge to/from the battery.
TP = test point. Makes a signal of interest on a PCB available to probes.
DMM = digital multi meter. Measures voltage, current, resistance and such.
PSU = power supply unit
wrt = with regard to *
EE = electrical engineering
PCB = See http://en.wikipedia.org/wiki/Printed_circuit_board

* Hey, you said you only understood AA batteries. ;-)
--
Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year
Wolfgang Spraul
2009-08-02 19:15:31 UTC
Permalink
Paul,
one more thing...
Post by Paul Fertser
To me it seems that CC readings are almost unused except for
presenting the user with a bit more accurate capacity data. And when
someone is developing something lowlevel he could as well connect and
external ampmeter, much more reliable and flexible approach.
This is where I'm not so sure. Also see Michal Brzozowki's mail.
I think real power consumption improvements in software can only be made if
it's throughout the whole stack, from kernel to middleware to apps.
I don't think you can optimize real system power consumption in the kernel
alone, where the kernel knows or correctly predicts all sorts of middleware or
app behavior.

So of course you first want the kernel situation, and charging, to be robust
and cover all cases. But then it should go on.
And I don't think we should assume every software developer has an ampmeter.
There are lots of application developers that could do valuable work if they
would get speedy and accurate readings on how much energy was consumed in the
last 5 minutes, 20 minutes, 2 hours, etc.

Now, if an accurate way to measure the current in the device solves 80% of that
as well, then the (big) extra cost of supporting CC batteries is not worth it.
So for me it all comes down to precision. Is it possible to build a cheap and
accurate way to measure current in the device?

For the NanoNotes, I will look into this first. If it's possible, this may be
all it needs to support application developers doing power consumption work.
If it's not possible, I think CC is good - I don't want to make the assumption
that you have to have an ampmeter to be able to do power consumption work.

Feedback very appreciated.
Wolfgang
Post by Paul Fertser
Post by Wolfgang Spraul
this is an excellent document, obviously I cannot spot anything wrong!
Thanks for you kind words. :)
Post by Wolfgang Spraul
I didn't know that some external chargers would not charge gta01 or gta02
batteries because of the thermistor check you are writing about.
I'm not sure i saw any charger like that myself or seen reports
(except on our wiki). But i suspect the probability of that for nokia
brand charges is quite high.
Post by Wolfgang Spraul
All the cheap external chargers we bought in Taiwan or China for testing can
charge both gta01 or gta02 batteries without a problem.
Proves my point :D
Post by Wolfgang Spraul
We will ship our first NanoNote with a BL-4C compatible battery, without
Coulomb counter (middle pin unused) [1].
Hm, can BL-5C fit there? Because it'd be much nicer as modern 5Cs have
quite some capacity.
Post by Wolfgang Spraul
How are people really using the Coulomb counter in gta02?
Theoretically I would think that it provides far superior power measurement
options for actual software development, just as you write.
For example when playing with power saving codes, whether in the kernel,
middleware or applications, I would think over the course of several hours or
days the Coulomb counter data is the primary means for efficient development.
To me it seems that CC readings are almost unused except for
presenting the user with a bit more accurate capacity data. And when
someone is developing something lowlevel he could as well connect and
external ampmeter, much more reliable and flexible approach.
Post by Wolfgang Spraul
So we are considering shipping the next version of the NanoNote with Coulomb
counter batteries same as the Neo FreeRunner.
But if nobody is actually using the data from the Coulomb counter, then it's a
wasted effort.
I'm not sure you'll get much for using CC.
The only problem so far with using a dumb battery on FR is that
there's no way to know the current from inside the device. On gta01
there's a resistor shunt supposed to be used to measure the current
but readings are too noisy to be useable. So if you have a good way to
measure current already i'd not go for CC.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
Paul Fertser
2009-08-02 19:22:40 UTC
Permalink
Post by Wolfgang Spraul
Post by Paul Fertser
To me it seems that CC readings are almost unused except for
presenting the user with a bit more accurate capacity data. And when
someone is developing something lowlevel he could as well connect and
external ampmeter, much more reliable and flexible approach.
Now, if an accurate way to measure the current in the device solves 80% of that
as well, then the (big) extra cost of supporting CC batteries is not worth it.
Yes, i think that's the case. The only state where integrated power measurement
readings are unavailable is suspend and that's quite low level
already.
Post by Wolfgang Spraul
So for me it all comes down to precision. Is it possible to build a cheap and
accurate way to measure current in the device?
bq27000 measures current accurately so it should be possible. I'm sure
there's some decent IC suitable for your task.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Wolfgang Spraul
2009-08-02 19:32:56 UTC
Permalink
Paul,
Post by Paul Fertser
Yes, i think that's the case. The only state where integrated power measurement
readings are unavailable is suspend and that's quite low level
already.
You could measure the current when you wake up, couldn't you?
Post by Paul Fertser
bq27000 measures current accurately so it should be possible. I'm sure
there's some decent IC suitable for your task.
bq27000 is a chip, right? You mean we should have that chip inside the device,
instead of having it in every battery?
That would make the batteries cheaper as well, I believe the CC batteries
cost 2 USD or so more than without CC :-(

Wolfgang
Post by Paul Fertser
Post by Wolfgang Spraul
Post by Paul Fertser
To me it seems that CC readings are almost unused except for
presenting the user with a bit more accurate capacity data. And when
someone is developing something lowlevel he could as well connect and
external ampmeter, much more reliable and flexible approach.
Now, if an accurate way to measure the current in the device solves 80% of that
as well, then the (big) extra cost of supporting CC batteries is not worth it.
Yes, i think that's the case. The only state where integrated power measurement
readings are unavailable is suspend and that's quite low level
already.
Post by Wolfgang Spraul
So for me it all comes down to precision. Is it possible to build a cheap and
accurate way to measure current in the device?
bq27000 measures current accurately so it should be possible. I'm sure
there's some decent IC suitable for your task.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
Paul Fertser
2009-08-02 19:46:06 UTC
Permalink
Post by Wolfgang Spraul
Post by Paul Fertser
Yes, i think that's the case. The only state where integrated power measurement
readings are unavailable is suspend and that's quite low level
already.
You could measure the current when you wake up, couldn't you?
It's possible with bq27k because it works autonomously. But if you do
something similar to gta01 there's no way to measure current in
suspend without an external equipment.
Post by Wolfgang Spraul
Post by Paul Fertser
bq27000 measures current accurately so it should be possible. I'm sure
there's some decent IC suitable for your task.
bq27000 is a chip, right? You mean we should have that chip inside the device,
instead of having it in every battery?
It would be a possible solution but it doesn't make much sense because
bq27k assumes it's connected to the same battery all the time. I meant
that since bq27k manages to measure the current accurately, there
should exist some other more simple IC (properly shielded to be immune
to noise) to measure the current inside a device. Also the charger IC
must know the current too, it's just that PCF50633 doesn't allow to
read it for some reason :(

There's also a possibility to use some other CC on device side, take
a look at http://focus.ti.com/docs/prod/folders/print/bq27510-g1.html
( $1.6 )
Post by Wolfgang Spraul
That would make the batteries cheaper as well, I believe the CC batteries
cost 2 USD or so more than without CC :-(
And also special batteries are always harder to source for
end-users. Especially if they're not located in EU or the USA.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Wolfgang Spraul
2009-08-02 20:00:45 UTC
Permalink
Paul,
Post by Paul Fertser
It's possible with bq27k because it works autonomously. But if you do
something similar to gta01 there's no way to measure current in
suspend without an external equipment.
Can't you measure current before and after suspend, and knowing how long you
were in suspend calculate energy consumption during suspend?

Wolfgang
Post by Paul Fertser
Post by Wolfgang Spraul
Post by Paul Fertser
Yes, i think that's the case. The only state where integrated power measurement
readings are unavailable is suspend and that's quite low level
already.
You could measure the current when you wake up, couldn't you?
It's possible with bq27k because it works autonomously. But if you do
something similar to gta01 there's no way to measure current in
suspend without an external equipment.
Post by Wolfgang Spraul
Post by Paul Fertser
bq27000 measures current accurately so it should be possible. I'm sure
there's some decent IC suitable for your task.
bq27000 is a chip, right? You mean we should have that chip inside the device,
instead of having it in every battery?
It would be a possible solution but it doesn't make much sense because
bq27k assumes it's connected to the same battery all the time. I meant
that since bq27k manages to measure the current accurately, there
should exist some other more simple IC (properly shielded to be immune
to noise) to measure the current inside a device. Also the charger IC
must know the current too, it's just that PCF50633 doesn't allow to
read it for some reason :(
There's also a possibility to use some other CC on device side, take
a look at http://focus.ti.com/docs/prod/folders/print/bq27510-g1.html
( $1.6 )
Post by Wolfgang Spraul
That would make the batteries cheaper as well, I believe the CC batteries
cost 2 USD or so more than without CC :-(
And also special batteries are always harder to source for
end-users. Especially if they're not located in EU or the USA.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
Paul Fertser
2009-08-02 20:16:11 UTC
Permalink
Post by Wolfgang Spraul
Post by Paul Fertser
It's possible with bq27k because it works autonomously. But if you do
something similar to gta01 there's no way to measure current in
suspend without an external equipment.
Can't you measure current before and after suspend, and knowing how long you
were in suspend calculate energy consumption during suspend?
You should certainly ask Joerg for a precise and qualified answer.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Rask Ingemann Lambertsen
2009-08-09 11:37:00 UTC
Permalink
Post by Wolfgang Spraul
How are people really using the Coulomb counter in gta02?
Theoretically I would think that it provides far superior power measurement
options for actual software development, just as you write.
For example when playing with power saving codes, whether in the kernel,
middleware or applications, I would think over the course of several hours or
days the Coulomb counter data is the primary means for efficient development.
To me: The clearly most useful part of the bq27000 is the current
measurement. You get what seems to be a reasonably accurate measure of the
current flow to/from the battery updated every 25 s or so. It's much more
practical than an external ammeter: No need to open the case and fiddle with
probes, you can measure battery current while in the train, at work or
wherever. Having it built in makes accurate current measurement available to
many more people in a lot more places.

Here's a few examples where the current measurements have proven useful:
1) Tracking down that current leak from the serial ports into the Calypso.
2) Finding that 8 mA apmd current leak Debian used to have.
3) Confirming the X.org server screen blanker current leak of 38 mA.
4) Measuring the effectiveness of reducing CPU clock and core voltage.

Hopefully it will also help to curb assorted forms of spyware because
they will be easier to detect with the power consumption figures readily
available.

I don't think it is worth it to spend a coulomb counter on each battery.
The selling point would be to keep track of battery degradation, but I've
already seen it change its mind from 1067 mAh to 1148 mAh - that's an error
of two hours worth of idle time at 100 MHz.

To get a charge level reading, add a voltmeter connected to the battery
terminals. As long as the charge and discharge rates are moderate, it will
be good enough.
--
Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year
Wolfgang Spraul
2009-08-10 11:54:03 UTC
Permalink
Rask,
I guess it comes down to price.
Most normal end users won't need the current measurement as they
don't do development, so adding an extra chip to do the measurement
either in the device or in every battery might not be worth it.

Maybe in the device just run a wire to the 3rd battery pin, then sell
it with a non-Coulomb counter battery normally, and offer the
Coulomb-counting battery as an add-on for developers?

Thanks a lot for your excellent feedback, we need to study this more...
Wolfgang
Post by Rask Ingemann Lambertsen
Post by Wolfgang Spraul
How are people really using the Coulomb counter in gta02?
Theoretically I would think that it provides far superior power measurement
options for actual software development, just as you write.
For example when playing with power saving codes, whether in the kernel,
middleware or applications, I would think over the course of several hours or
days the Coulomb counter data is the primary means for efficient development.
To me: The clearly most useful part of the bq27000 is the current
measurement. You get what seems to be a reasonably accurate measure of the
current flow to/from the battery updated every 25 s or so. It's much more
practical than an external ammeter: No need to open the case and fiddle with
probes, you can measure battery current while in the train, at work or
wherever. Having it built in makes accurate current measurement available to
many more people in a lot more places.
1) Tracking down that current leak from the serial ports into the Calypso.
2) Finding that 8 mA apmd current leak Debian used to have.
3) Confirming the X.org server screen blanker current leak of 38 mA.
4) Measuring the effectiveness of reducing CPU clock and core voltage.
Hopefully it will also help to curb assorted forms of spyware because
they will be easier to detect with the power consumption figures readily
available.
I don't think it is worth it to spend a coulomb counter on each battery.
The selling point would be to keep track of battery degradation, but I've
already seen it change its mind from 1067 mAh to 1148 mAh - that's an error
of two hours worth of idle time at 100 MHz.
To get a charge level reading, add a voltmeter connected to the battery
terminals. As long as the charge and discharge rates are moderate, it will
be good enough.
--
Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year
_______________________________________________
Openmoko community mailing list
http://lists.openmoko.org/mailman/listinfo/community
Sebastian Krzyszkowiak
2009-08-10 12:10:33 UTC
Permalink
Post by Wolfgang Spraul
Rask,
I guess it comes down to price.
Most normal end users won't need the current measurement as they
don't do development, so adding an extra chip to do the measurement
either in the device or in every battery might not be worth it.
Maybe in the device just run a wire to the 3rd battery pin, then sell
it with a non-Coulomb counter battery normally, and offer the
Coulomb-counting battery as an add-on for developers?
Thanks a lot for your excellent feedback, we need to study this more...
Wolfgang
Post by Rask Ingemann Lambertsen
Post by Wolfgang Spraul
How are people really using the Coulomb counter in gta02?
Theoretically I would think that it provides far superior power measurement
options for actual software development, just as you write.
For example when playing with power saving codes, whether in the kernel,
middleware or applications, I would think over the course of several hours or
days the Coulomb counter data is the primary means for efficient development.
To me: The clearly most useful part of the bq27000 is the current
measurement. You get what seems to be a reasonably accurate measure of the
current flow to/from the battery updated every 25 s or so. It's much more
practical than an external ammeter: No need to open the case and fiddle with
probes, you can measure battery current while in the train, at work or
wherever. Having it built in makes accurate current measurement available to
many more people in a lot more places.
1) Tracking down that current leak from the serial ports into the Calypso.
2) Finding that 8 mA apmd current leak Debian used to have.
3) Confirming the X.org server screen blanker current leak of 38 mA.
4) Measuring the effectiveness of reducing CPU clock and core voltage.
Hopefully it will also help to curb assorted forms of spyware because
they will be easier to detect with the power consumption figures readily
available.
I don't think it is worth it to spend a coulomb counter on each battery.
The selling point would be to keep track of battery degradation, but I've
already seen it change its mind from 1067 mAh to 1148 mAh - that's an error
of two hours worth of idle time at 100 MHz.
To get a charge level reading, add a voltmeter connected to the battery
terminals. As long as the charge and discharge rates are moderate, it will
be good enough.
Well, for me user experience when using CC battery is much better when
using dumb battery. I just tested dumb battery on my gta02 yesterday,
and it works fine... but seeing percentage growing up without any
charger connected isn't thing which normal user wants to see ;)
--
Sebastian Krzyszkowiak
dos
Adam Wang
2009-08-13 04:50:58 UTC
Permalink
Hi,
Post by Rask Ingemann Lambertsen
To me: The clearly most useful part of the bq27000 is the current
measurement. You get what seems to be a reasonably accurate measure of the
current flow to/from the battery updated every 25 s or so. It's much more
practical than an external ammeter: No need to open the case and fiddle with
probes, you can measure battery current while in the train, at work or
wherever. Having it built in makes accurate current measurement available to
many more people in a lot more places.
1) Tracking down that current leak from the serial ports into the Calypso.
2) Finding that 8 mA apmd current leak Debian used to have.
3) Confirming the X.org server screen blanker current leak of 38 mA.
4) Measuring the effectiveness of reducing CPU clock and core voltage.
It's an good easy way proposed, it would be probably get the related
current leak to spyware.
But I just wondering that is there anyone who really did a whole current
measurement about
battery's consumption; not only indicators are partly in percentage. Any
exact plot of current
curve have illustrated by CC/CV mode [1]? then compared to battery's
specification to check?
I am searching that is there an existing linux software that it can
remote DMM measure to do
real current/voltage measure. Hope someone knows.

Adam
Post by Rask Ingemann Lambertsen
Hopefully it will also help to curb assorted forms of spyware because
they will be easier to detect with the power consumption figures readily
available.
[1] http://focus.ti.com/lit/ml/sprp569/sprp569.pdf
Rafael Campos
2009-08-03 08:05:58 UTC
Permalink
Nice discussion on the follow mails, but i've a doubt
Post by Paul Fertser
Hi,
This is a text version of the wikipage [1], feel free to ask new questions
there on the talk page. Discussion on this ML is also appreciated (and
in fact i'm more comfortable with ML than the wiki).
Openmoko devices
Battery questions and answers
NB: Some of the described behaviour depends on the kernel, the
relevant code was pushed on 02 Aug to andy-tracking
Hardware capabilities
Q: What batteries can be used with gta01 and gta02?
A: Original OM gta01, gta02, Nokia BL-5C, BL-6C and compatibles.
Q: Do other BL-5/6C compatible batteries fit?
A: If the battery is thicker than BL-6C, you won't be able to close
the back cover.
Q: What is the difference between all those types?
gta01, gta02 - 1200 mAh
BL-5C old (newer/new) - 850 (970/1050) mAh
BL-6C - 1150 mAh
gta01, BL-5C, BL-6C - thermistor
gta02 - bq27000
gta02 - accurate and sophisticated reporting of capacity,
time_to_full, time_to_empty, temperature and battery current during
both charge and discharge thanks to bq27000 (aka Coloumb Counter)
Q: What are hardware capabilities of gta01 and gta02 with regard to
battery management?
gta01: charging all battery types, measuring temperature with
battery-integrated thermistor (currently charging and measuring
temperature for non-gta01 batteries doesn't work due to the kernel
driver issues but it's software limitation), measuring battery output
voltage, very inaccurate and noisy measuring of battery current
gta02: charging all battery types, measuring battery output voltage,
communicating with bq27000
Q: Can nokia phones use/charge gta01/gta02 batteries?
A: gta01 and gta02 batteries will fit wherever BL-6C fits but they
can't be charged in nokia phones unless you isolate the middle pin
from the battery and connect a resistor of ~50k (actual measured value
on a cold (25C) battery is 75k, on a slightly warm battery - 82k) from
it to the ground (to fake a thermistor presence).
Q: Can third-party chargers charge gta01/gta02 batteries?
A: The "good" ones will most probably require the same trick needed
for nokia phones. More cheaper ones are more likely to ignore
thermistor absence.
Q: I have several compatible batteries. What are the storage
requirements for them?
A: Keep in a dry cool place charged to no more than 75%.
Safety issues
Q: Do OM devices control temperature to stop charging if the battery
gets too hot?
A: No (probably gta01 does, need to check).
Q: Isn't it dangerous?
A: No, since all batteries (not raw cells!) have an integrated
protection circuits.
Q: Can i use that fancy 2800 mAh BL-5C-compatible battery i saw on
ebay?
A: Unless you want an explosion in your pocket i wouldn't recommend
using any battery that is not produced by a reputable vendor and
widely tested. And even reputable vendors make mistakes, nokia once
had to recall 46 million batteries manufactured by Matsushita (
http://batteryreplacement.nokia.com/batteryreplacement/en/advisory-2007.html
).
Q: You say that BL-5C is compatible with my gta02. Does that mean i
can use that BL-5C-compatible bat i bought for a buck from a bum?
A: You bet, go ahead.
Charging
Q: My battery charges to 100% but then charging stops and the battery
keeps discharging, wtf?
A: LiIon batteries don't like to be kept fully charged, so the charger
stops as soon as charging current becomes less than threshold. If you
have GSM on it will discharge the battery.
Q: But why doesn't it ever stop charging on my device?
A: The GSM modem is connected directly to the battery terminals so if
it's active, charger will think it's still charging the battery and
won't turn off unless GSM becomes inactive. The default threshold is
about 16mA, the latest Qi increases the threshold to ~32mA.
Is this true for gta02 deevices only or it's the same for gta01?
Post by Paul Fertser
Q: Does it mean if i leave my phone plugged it will eventually fully
discharge the battery?
A: On gta02 the charger will restart the charge automatically once the
battery voltage reaches ~4V which corresponds to ~76%. Not sure about
gta01, requires more investigation. :-/
Q: Ok, how to make sure my battery is fully charged before a long
trip?
A: Replug the charger, it will trigger charging no matter what the
current capacity is.
Q: My power/aux LED indicates charging/discharging/whatever, what does
that mean (aka why it's still blue even after i unplugged the
charger)?
A: Ask FSO guys about it, some of them think that the user shouldn't
really know what's happening and therefore they do some special
mangling of "status" sysfs node before presenting it to the user. If
you want to make a decent bugreport please add clear steps to
reproduce and /sys/class/power_supply/battery/uevent contents for all
relevant states.
Using compatible batteries with gta02
Q: So, how do i use "dumb" batteries with my freerunner?
echo bq27000-battery.0 > /sys/bus/platform/drivers/bq27000-battery/unbind
modprobe gta01_battery
rmmod gta01_battery
echo bq27000-battery.0 > /sys/bus/platform/drivers/bq27000-battery/bind
If you use Enlightment you might need to restart it after that.
Q: Is capacity reported for dumb batteries accurate?
A: During discharge it should be pretty (+-10%) accurate, during
charge the capacity reported is ~20% more than real.
Q: Why does /sys/class/power_supply/battery/charge_full says i have a
850 mAh battery no matter what i use?
A: It's a workaround to make popular battery gadgets work with this
driver.
This Q&A were prepared by
[1] http://wiki.openmoko.org/wiki/Battery_Questions_and_Answers
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
_______________________________________________
Openmoko community mailing list
http://lists.openmoko.org/mailman/listinfo/community
Regards,
--
___________
Rafael Campos
o0 Methril 0o
http://openblog.methril.net/
Paul Fertser
2009-08-07 17:28:04 UTC
Permalink
Post by Paul Fertser
Q: But why doesn't it ever stop charging on my device?
A: The GSM modem is connected directly to the battery terminals so if
it's active, charger will think it's still charging the battery and
won't turn off unless GSM becomes inactive. The default threshold is
about 16mA, the latest Qi increases the threshold to ~32mA.
Is this true for gta02 deevices only or it's the same for gta01?
I need to look it up in the datasheet and u-boot for gta01 sources to
say for sure. It should be roughly the same for gta01, if it's not,
it's a bug and should be fixed.
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
mailto:***@gmail.com
Rask Ingemann Lambertsen
2009-08-10 00:35:26 UTC
Permalink
Post by Rafael Campos
Nice discussion on the follow mails, but i've a doubt
Post by Paul Fertser
Q: But why doesn't it ever stop charging on my device?
A: The GSM modem is connected directly to the battery terminals so if
it's active, charger will think it's still charging the battery and
won't turn off unless GSM becomes inactive. The default threshold is
about 16mA, the latest Qi increases the threshold to ~32mA.
Is this true for gta02 deevices only or it's the same for gta01?
The threshold on the gta01 can be 0.05, 0.10, 0.20 or 0.40 times Ifast,
where Ifast is 111 mV / 0.22 Ohm = 504 mA. The gta01 uses a threhold of 0.2
* Ifast = 100 mA.

Btw, on the gta02, there's a switch U1705 between the battery and the GSM
modem. It's not like on the gta01 where the GSM modem can stay on while the
gta01 is otherwise turned off.
Post by Rafael Campos
Post by Paul Fertser
Q: Does it mean if i leave my phone plugged it will eventually fully
discharge the battery?
A: On gta02 the charger will restart the charge automatically once the
battery voltage reaches ~4V which corresponds to ~76%. Not sure about
gta01, requires more investigation. :-/
I looked at the PCF50606 manual. I can't see where it restarts charging
automatically.
--
Rask Ingemann Lambertsen
Danish law requires addresses in e-mail to be logged and stored for a year
Timo Juhani Lindfors
2009-08-03 16:04:18 UTC
Permalink
Post by Paul Fertser
Q: I have several compatible batteries. What are the storage
requirements for them?
A: Keep in a dry cool place charged to no more than 75%.
My new gta02 battery shows capacity of 0% when I plug it in and starts
to slowly charge. Is it better to charge it to ~40% than to keep it at
0%?

Could the capacity measurement get confused during long storage?
Timo Juhani Lindfors
2009-08-03 19:39:04 UTC
Permalink
Post by Timo Juhani Lindfors
Could the capacity measurement get confused during long storage?
Answering to myself here: When I charged the battery capacity
increased steadily but when it reached 67% it suddenly jumped to 100%
in one minute. I think this concludes that the capacity reported by
Linux is not always correct.
Al Johnson
2009-08-04 01:10:10 UTC
Permalink
Post by Timo Juhani Lindfors
Post by Timo Juhani Lindfors
Could the capacity measurement get confused during long storage?
Answering to myself here: When I charged the battery capacity
increased steadily but when it reached 67% it suddenly jumped to 100%
in one minute. I think this concludes that the capacity reported by
Linux is not always correct.
Where exactly is this figure from? Are you looking at the battery monitor
sysfs entry, or something that gets the incorrect figure from hal?
Sebastian Krzyszkowiak
2009-08-04 11:35:41 UTC
Permalink
Post by Al Johnson
Post by Timo Juhani Lindfors
Post by Timo Juhani Lindfors
Could the capacity measurement get confused during long storage?
Answering to myself here: When I charged the battery capacity
increased steadily but when it reached 67% it suddenly jumped to 100%
in one minute. I think this concludes that the capacity reported by
Linux is not always correct.
Where exactly is this figure from? Are you looking at the battery monitor
sysfs entry, or something that gets the incorrect figure from hal?
I think he's talking about E battery metter, which proves that he's wrong ;)
--
Sebastian Krzyszkowiak
dos
Timo Juhani Lindfors
2009-08-05 18:50:05 UTC
Permalink
Post by Sebastian Krzyszkowiak
I think he's talking about E battery metter, which proves that he's wrong ;)
Sorry for the late reply, but no, I don't run any E stuff :-)
Timo Juhani Lindfors
2009-08-05 18:49:33 UTC
Permalink
Post by Al Johnson
Where exactly is this figure from? Are you looking at the battery monitor
sysfs entry, or something that gets the incorrect figure from hal?
current_now file from sysfs.
Paul Fertser
2009-08-04 19:21:29 UTC
Permalink
Post by Timo Juhani Lindfors
Post by Timo Juhani Lindfors
Could the capacity measurement get confused during long storage?
Answering to myself here: When I charged the battery capacity
increased steadily but when it reached 67% it suddenly jumped to 100%
in one minute. I think this concludes that the capacity reported by
Linux is not always correct.
Yes, that's the info from bq27000 that you see. I'll soon expose the
flag that tells if bq27000 is certain in its values or not.

So yes, i recommend to charge the battery before storage a bit (~50%
is ok), and to be sure of capacity to do a calibration cycle (which
i'll describe later).
--
Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
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