See Estel's guide here and very nice piece of scripts he put together called bnf.

Try turning it on, wait around 2 sec and then plug in the charger it should boot eventually. Why is this happaning I have no clue but mine was behaving similarly...

Maybe springs that holds battery in place needs tightening? Also, single battery could just got discharged beyond safe limit. Check it's voltage with multimeter.

/Estel

Good point Estel, definately worth checking but that wasn't the case for neither of them on my device. The problem was gone since I flashed it to thumb from testing cssu.

Does anybody know if those blue dream scuds will be available again?

Thanks Estell for bq27x00 scripts and tutorial on battery capacity measurement; you stated that after the first time running the bq*.sh script you can do anything except for turning the device off.

I'd like to know if we can also recharge the device in that time? I recharged to 100% and ran the bq*.sh once. Now if I connect the N900 to USB a few times (but not let it go 100%) it affects the measurement?

Im hopefully receiving some soon for testing so we again have a supplier. (avartardeals)

I've been transferring files over mass-storage (without disabling bme, so it definitely charged), without affecting VDQ. Yet, if You overdo it - for example, connect and disconnect many times, or charge for too long - VDQ will reset to 0, until next full charge.

/Estel

BATTERY GAUGE CHIP BQ27200 SEMI-AUTOMATIC CALIBRATION

for your convenience: http://maemo.cloud-7.de/maemo5/patch...brate-bq27k.sh automatic calibration script for bq27200 chip.

(serving suggestion:

Code:

root
cd $(dirname $(which bq27200.sh)); 
wget http://maemo.cloud-7.de/maemo5/patches_n_tools/calibrate-bq27k.sh;
chmod +x calibrate-bq27k.sh

)

HOW TO USE:
There are two slightly different modes to use this:

• first plug in wallcharger, then start the script

  will start charging battery on plugin of charger, and script waits untill battery full and VDQ:1, before the discharging begins (tested)

• first start the script, then plug in wallcharger

  the script, when finding a valid discharge process (VDQ:1) in progress, will try to stop charging (also emergency charging aka flatbatrecover) and continue to DIScharge battery until the learning cycle complete. Advantage: faster. Tested to work by Kerio

You will need bq27200.sh (also here, plain file) installed (incl i2ctools) - quite probably you already have that otherwise why would you want to calibrate bq27200 chip ;-)
and you need to cd to the directory where bq27200.sh lives, before starting the calibrate-bq27k.sh script (the script calls ./bq27200.sh).

The script will

• charge battery until full (actually until VDQ:1), then
• switch off charging (stop bme) and
• discharge battery until
• learning cycle complete (EDV1:1), when it will
• re-enable charging by starting bme.

For proper unattended discharging/calibrating during you're asleep in the night, you want to set screen backlight to 'always on' and level 5 (will result in discharge during ~4h).
Don't feel shocked when BME starting charging - after learning cycle - will leave device completely dark - some even think it's not something exactly inconvenient. Just engage lockslider 2 times to 'revive' your acting dead device ;-) (or un-comment last line in calibrate-bq27k.sh which restarts mce and thus as well reverts backlight to normal operation)

PS: you'll probably need root for all of the above

enjoy
/jOERG

ps: you may want to check for improved or bugfixed script versions every now and then. I won't announce every minor update here.

Dr. Frost!

Nice to see you are still the dean of the "College of Nokia N900 Power". You are, indeed, a cornerstone of the community.

I'm back from the dead and am considering putting something together for the current contest. It would definitely be something security related as that is the vast majority of my work. My understanding is that I have approximately six weeks. I'm trying to set some time aside.

I have been using the pitiful Mugen battery. I loathe it. I am now going to try to get my hands on the much loved Scud batteries. I can't decide if I want to use a single or put two in series. Anyway - point me in the right direction.

Side note: If anyone has any wishes for some specific security application/solution - I am all ears.

Cheers,

Abe