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High power drain when disconnected from charger
So, My n900 eats batteries in 3-4 hours. Even when idle the thing warms my pocket quite nicely.
I've checked top and the cpu is at about 3-4% while idle. I found powerscript and have been running it to profile the system's power consumption. When on the charger, it reports 0-10mA power draw when idle. As soon as I yank the charger it jumps up to ~375mA, and stays at that level while running on battery. So with a 1300mAh battery, that'll get me < 4 hours. As soon as I plug it back in the power usage drops back to <10mA. Am I interpreting the powerscript output correctly? Should it give vastly different readings when plugged into the charger or not? I've got the power kernel, CSSU, and a few apps installed. CPU stays around 3-4%. I've tried with gprs, wifi, bt, & gps turned off. No change. Any suggestions of where else to look? Thanks! |
Re: High power drain when disconnected from charger
I have never used powerscript so I cannot make much sense out of the information you have mentioned along with the report that I'm getting when I just tried that script on my device.
I am guessing that when you took your device off the charger your CPU would state somewhere around 50-100% CPU usage? The best idea is to run top (as root) and unplug the device whilst top is still running. I am assuming there is a possible case of a stuck process somewhere that is using up large chunks of CPU somewhere.. and/or thrashing I/O. Also has your device ever been overclocked? |
Re: High power drain when disconnected from charger
what battery are you using? stock battery or one of eBay (some batteries say their much more than what they actually are)
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Re: High power drain when disconnected from charger
@tuxsavvy - That's the weird thing, top shows CPU at less that 10% CUP usage. Just X and hildon stuff show up but only at a few percent each. No processes appear to be out of control. CPU use doesn't change when I disconnect the charger, just the power consumption.
I recently reflashed and installed only the power kernel as well as the batterypatch. It is overclocked to 750MHz. @randomdood - I've got 2 BL-5J batteries. One came with the phone, the other I got on Amazon. They both report over 1200mAh after charge. I'm gonna try a complete reflash and will test again with stock PR1.3. |
Re: High power drain when disconnected from charger
I haven't tested after a complete reflash yet, but I have noticed that even after turning off the device, it stays warm and will drain the battery while "off".
Wondering if I have a "hardware issue"? :( |
Re: High power drain when disconnected from charger
Just some more data til I find a fix. This was all captured while logged in via ssh over wifi with the phone locked. GPS, bluetooth, FM all off.
Here's powerscript output while on the charger. (note the mA readings): Code:
Tue Sep 27 14:16:21 EDT 2011 3mA 119 total events, 23.752 events/sec Code:
Tue Sep 27 14:17:16 EDT 2011 189mA 429 total events, 85.662 events/sec Code:
Mem: 224300K used, 13012K free, 0K shrd, 9772K buff, 71920K cached Here's powertop output while on the charger: Code:
Nokia-N900:~# powertop Code:
Nokia-N900:~# powertop |
Re: High power drain when disconnected from charger
Update...
I did a complete reflash of my n900 (eMMC & FIASCO) to PR1.3. Fully charged it, turned off wifi, gps, bluetooth & let it sit idle. Battery was dead in a few hours. Then I installed only i2c-tools to get power measurements from powerscript. The problem remains: On charger, system pulls 0-50mA. As soon as charger is disconnected, it constantly pulls ~350mA and stays nice & warm. If left idle, according to top, CPU use stays at less than 5% in both cases, 0% io, 0% irq. Batteries still drain in <4hours. I tried installing the batterypatch for the non-power kernel, but it had no effect. meh... is this just something I have to accept? |
Re: High power drain when disconnected from charger
Did you try removing or replacing the SIM card with a different one? I remember reading some reports when N900 first came out about people with a flaky SIM card that caused battery drain. It would be interesting to try. Also try removing your SD card if you have one inserted. How it would be related to charging, I have no idea... grasping at straws.
Also try Offline mode, if you haven't already. It should normally last several days idling in Offline mode (but of course it's no fun...) |
Re: High power drain when disconnected from charger
I haven't tried without the sim yet. My sim is several years old and has been used in a few phones. I'll give it a try.
I only added an sd card last night to back stuff up before reflashing. The problem existed before and after that so I doubt its the sd card. I tried offline mode & tablet mode but it didn't help. I'll yank the sim & report back. |
Re: High power drain when disconnected from charger
No luck with the sim removed. :( All the contacts looked fine.
I mentioned earlier that it stays warm and drains the battery when powered off (either via gui or by holding the power button for ~10secs). It seem to be in a lame sleep mode since when I power it on, it sometimes boot up in a couple secs skipping the hands startup screen. If I yank the battery and put it back in, it stays off. But once I turn it on, it (the charger/power supply) seems to latch on and suck juice. I'm leaning toward a "hardware" issue a this point. Other than the high discharge rate when off the charger the phone works flawlessly, just have too leave it plugged in all the time. argh. |
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