maemo.org - Talk - N900 battery discharges very quickly: small rant about rare but sharply annoying problem

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N900 battery discharges very quickly: small rant about rare but sharply annoying problem

1. It's not a battery problem. This week, I have once left N900 during the night (eight hours or more) running Modrana, with GPS and cellular connection on, and it has lost at most 25% (more likely, 10%) of the charge. So, the battery holds its charge. Despite the many grains of sand that found their way inside the device.
2. It's not a WiFi problem. WiFi was turned off. No Internet connection at all. Though... Let me remember... I have tried to access a WiFi connection, N900 said 'connected', browser said 'authenticate before you can access Internet', I said 'disconnect' (it was not like I really needed Internet, just curious about many WiFis floating around). But it's still not enough explanation for draining the battery, since all WiFi operations were done within three minutes, and afterwards it was disconnected.
3. Let me explain the timeline:
3.1. Battery 8/8. Turning on 2G cellular connection, Modrana, going on a trip.
3.2. Battery 8/8. Occasinally turning on and off 3G, starting up and down Modrana, with GPS on, switching between Silent and General Profiles.
3.3. Battery 8/8. N900 warm, no applications open. When starting top in terminal, CPU usage jumps from 50% to 5%. Still, battery 8/8. Is there any bug when battery shows '8/8' while the charge is much lower?
3.4 Less than half-an-hour later, during a telephone call, without any warning (like 'Battery low' or 'Shutting down'), N900 blacks out. And, of course, it cannot be turned on again: darkened 'Nokia' logo, yellow led (not blinking), then returning to black screen, and not even attempting to start up - evidently, not enough battery. It can be turned on again only after some looong recharge. Add to that that I have not taken the charger (not even the USB cable) with me (I have seen the 8/8 battery, and it's not like such sudden discharges happen every day), that there is free electricity around, and even free USB ports... Close to the torments of Tantalus. Especially when there is no other cellular phone, no other navigation tool, no other electronic camera around. It's a poor consolation that there is non-electronic watch, or I would have had to look time up on the tower, listening to the bells.
4. It might be bug 9150, or not. Is bug 9150 going to be solved anytime soon? It has turned out to be reproducible around 2011-01-28.
5. Whatever drains the battery, the watchdog should have noticed the drain before it was drained to zero. The watchdog should have restarted the device when the battery still had enough charge to boot the device up, and give it a hour or two of 'slow' functioning - cellular connection, no WiFi, no GPS, no music, no video.
Does anybody have any possible explanation of the extra quick drain, or suggestions how to prevent it from being repeated in the future? Is CSSU better protected from such occurrences?
Thank you for your support.