Battery Voltage fluctuates

[saint_david]

I've had really poor battery performance for the past couple of weeks and have noticed that the battery voltage levels fluctuate quite a bit (using the bettery stats app from spare parts). Is it normal for the voltage levels of the battery to vary at all?

[prettyboy85712]

The faulty battery status is a know issue in the current build of cupcake.

[simms22]

Everytime you reboot your phone , throws off the battery meter . Discharge the battery fully , then charge to 100% , then reboot . This should make it accurate again . Also , if you are rooted , you can enter this script before you rebbot . In terminal type....

su
rm /data/system/batterystats.bin

[simms22]

Everytime you reboot your phone , throws off the battery meter . Discharge the battery fully , then charge to 100% , then reboot . This should make it accurate again . Also , if you are rooted , you can enter this script before you rebbot . In terminal type....

su
rm /data/system/batterystats.bin

[extorian]

It's certainly normal for batteries to change voltage under different circumstances... I don't know if this accounts for what you're seeing, but let me use some examples.

The voltage of a fully charged G1 battery might be around, say, 4.2v. If you don't use your phone and just leave it on your desk, it will drop slowly to around, say, 3.2v (I'm guessing on these figures, but they should be close) as it discharges to about 5% to 10% full over a day or two. At which point the voltage suddenly drops off sharply, and when it does this your phone turns off. This is called the discharge curve, and makes a graph that looks a bit like river and waterfall viewed from the side (it gradually goes downhill in a straight line, then drops off suddenly at the end).

When you use your phone more so that it draws more power (in this case, say - play a game, make a call, use the GPS/Maps, etc) the battery voltage will drop in proportion to the additional load. If you compared it to the standard discharge curve above, the voltage would be somewhat lower than what you'd expect it to be. This is normal.

When you use your phone less (i.e. turn the screen off, stop using it) the battery voltage will bounce back from the above drop back to where the standard discharge curve line is.

It should be noted her, that booting your phone puts the battery under significant load, which may throw the battery meter off.

So, this might explain why you're seeing weird voltages going up and down, as the voltage will drop when the phone is putting the battery under high load, and the voltage will increase again as it rests.

There is also something I don't want to get into the physics of, called the recovery effect. This is where when you remove all load from a battery for a time (i.e. turn the device off for a few minutes, an hour, whatever), the battery will appear to have recharged slightly all on it's own. This also throws the battery meter off, as this phenomenon is short lived, and the battery will quickly discharge back to the level of that graph we talked about above.