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Help Battery incorrect reading?

MrBaker22

Well-Known Member
I took my battery out of my phone the other day while the phone was on, the battery read 26% when i rebooted the phone it read 13% does anyone know why this is ? could the battery be faulty or calibrated wrong ?


Any advice welcome :)
 
Apparently completely charging, fully discharging and then completely charging the battery will recalibrate it.

Not sure how much truth there is to this as you can't fully discharge a li-ion battery. Devices prevent you from doing this. Running the battery until your device turns off will probably in reality discharge the battery about 95% or something.
 
Apparently completely charging, fully discharging and then completely charging the battery will recalibrate it.

Not sure how much truth there is to this as you can't fully discharge a li-ion battery. Devices prevent you from doing this. Running the battery until your device turns off will probably in reality discharge the battery about 95% or something.


Thankyou, if i discharge it until the phone shuts off will this harm the battery? and when i fully charge it after the discharge should i charge it and leave it alone or charge it while phone is off etc....
 
fully discharging once or twice won't harm. repeatedly doing so is bad for the battery.

if you've fully discharged with the aim of recalibrating, you should recharge to 100% without using
 
fully discharging once or twice won't harm. repeatedly doing so is bad for the battery.

if you've fully discharged with the aim of recalibrating, you should recharge to 100% without using


Thankyou, Right i know now not to use it while its doing the final charge, should i turn the phone off while its doing the final recharge ?
 
Thankyou, if i discharge it until the phone shuts off will this harm the battery? and when i fully charge it after the discharge should i charge it and leave it alone or charge it while phone is off etc....

Sorry I should've been more clear.

Fully discharging the battery in terms of running it until the phone shows 0% is fine, but this isn't truly completely discharging the battery. As far as I understand it a li-ion battery will stop working if it's *completely* discharged, so devices have to prevent the battery from being fully discharged. They would do this by reporting 0% charge and shutting down when, in reality, there's about 5% charge left in the battery.

Running the battery until the phone shuts down isn't harmful at all to the battery. Most batteries will last for a certain number of full cycles until they need to be replaced. Running the phone to 50% and then charging it, and doing that twice, would have the same effect on your battery as running it to 0% once.
 
just to report i followed the steps given to the Tee, and my battery is still draining 10% in just over an hour, thats with just a small amount of web browsing and a couple texts,

am i just being picky ? or is it ot right ?
 
just to report i followed the steps given to the Tee, and my battery is still draining 10% in just over an hour, thats with just a small amount of web browsing and a couple texts,

am i just being picky ? or is it ot right ?

Doesn't sound right to me.

My battery stats now:

90%
1hr 32m 11s on battery
39m 15s on display
~about 15 minutes browsing
1 telephone call, 1 text
5 minutes gaming

Can you post a screenshot of your battery stats page? If you don't know how to take a screenshot, hold down the home button and then tap the power button and it'll save a screenshot to your gallery.
 
Doesn't sound right to me.

My battery stats now:

90%
1hr 32m 11s on battery
39m 15s on display
~about 15 minutes browsing
1 telephone call, 1 text
5 minutes gaming

Can you post a screenshot of your battery stats page? If you don't know how to take a screenshot, hold down the home button and then tap the power button and it'll save a screenshot to your gallery.

As you requested
 

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As you requested

Seems like a typical stat display to me, nothing looks too out of the ordinary. Display is by far the most power hungry thing on the device.

5% in half an hour isn't too unusual considering you were actually using the device. 5% would be bad if it was just sat in your pocket.

The only thing I would say is an actual problem is that it dropped 13% when you rebooted the phone.. that would indicate a battery or calibration problem. I would try a full battery cycle to see if things improve and, if not, maybe ask if you can have the phone replaced.
 
Seems like a typical stat display to me, nothing looks too out of the ordinary. Display is by far the most power hungry thing on the device.

5% in half an hour isn't too unusual considering you were actually using the device. 5% would be bad if it was just sat in your pocket.

The only thing I would say is an actual problem is that it dropped 13% when you rebooted the phone.. that would indicate a battery or calibration problem. I would try a full battery cycle to see if things improve and, if not, maybe ask if you can have the phone replaced.

I did a battery cycle last night and its still draining quick and im hardly using it bit of web browsing and text messages, i have litening rom on here they wont replace the phone or battery will they? This my latest usage ive hardly been using it and its on 79% its been kike under 2 hours ......
 

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Also ive just pulled my battery out while phone was on the put back in the battery and rebooted and it was on 77% and it dropped too 66% ..... any advice ?
 
I did a battery cycle last night and its still draining quick and im hardly using it bit of web browsing and text messages, i have litening rom on here they wont replace the phone or battery will they? This my latest usage ive hardly been using it and its on 79% its been kike under 2 hours ......

Duh I should've realised you were rooted, it didn't click with me that you had different icons at the top :p

Do you have clockworkmod recovery? If so, that has a "wipe battery stats" feature in the "advanced" menu which might help.

79% is terrible for under two hours, definitely looks like something might be wrong. Has anything else shown up in your stats?

For comparison's sake my battery has been on for 3hr 42m and I'm on 80%. Unrooted, push emails enabled, about 30 text messages (sent+received), few facebook checks, bit of browsing, the usual stuff.

I wonder if your ROM has changed the way the processor underclocks when the screen is turned off? You could try installing SetCPU and setting up your own screen off profile.
 
Also ive just pulled my battery out while phone was on the put back in the battery and rebooted and it was on 77% and it dropped too 66% ..... any advice ?

^ try wiping the battery stats, then if that doesn't help I would unroot the phone and get it swapped as dropping 11% like that is bizarre.
 
^ try wiping the battery stats, then if that doesn't help I would unroot the phone and get it swapped as dropping 11% like that is bizarre.

I dont know what that clockwork is .... and how do i unroot? Just install the firmware i was on through odin? Its annoying that my battery is droppig this quick does your phone lose battery like mine if you take the battery out while the phone is on and you reboot it?
 
I dont know what that clockwork is .... and how do i unroot? Just install the firmware i was on through odin? Its annoying that my battery is droppig this quick does your phone lose battery like mine if you take the battery out while the phone is on and you reboot it?

When you start up the phone, try holding volume down at the same time as power and it should boot into some kind of recovery menu. There might also be a reboot into recovery option in the power menu - not sure as I haven't rooted the SGS2.

I'm not going to try it, you shouldn't really turn the phone off in that way. It doesn't lose any battery with a normal reboot and if I pull the battery while the phone is off. Does it lose battery if you do a normal switch off, pull the batter, switch on?

Finally, not 100% how you would go about unrooting as I've not rooted the SGS2.. all of my rooting knowledge is for the HTC Desire :p You could try asking in the "all things root" subforum though and they'll be able to help.
 
When you start up the phone, try holding volume down at the same time as power and it should boot into some kind of recovery menu. There might also be a reboot into recovery option in the power menu - not sure as I haven't rooted the SGS2.

I'm not going to try it, you shouldn't really turn the phone off in that way. It doesn't lose any battery with a normal reboot and if I pull the battery while the phone is off. Does it lose battery if you do a normal switch off, pull the batter, switch on?

Finally, not 100% how you would go about unrooting as I've not rooted the SGS2.. all of my rooting knowledge is for the HTC Desire :p You could try asking in the "all things root" subforum though and they'll be able to help.


i lose about 13% when i pull the battery when the phone is on and reboot, i loose about 1 or 2% when i shutdown normally and then reboot, i think im going to unroot and go get a new handset today only had it a few days, but yes 2 hours light - moderate use and it drops to 79% so as you say i think something may be wrong
 
i lose about 13% when i pull the battery when the phone is on and reboot, i loose about 1 or 2% when i shutdown normally and then reboot, i think im going to unroot and go get a new handset today only had it a few days, but yes 2 hours light - moderate use and it drops to 79% so as you say i think something may be wrong

Right well you're not meant to pull the battery when the phone is on, only do that if you really have to... like if it totally crashes. So I would stop doing that.. but the high battery usage could definitely be a sign of a problem.

Probably best to get a replacement just in case.
 
Right well you're not meant to pull the battery when the phone is on, only do that if you really have to... like if it totally crashes. So I would stop doing that.. but the high battery usage could definitely be a sign of a problem.

Probably best to get a replacement just in case.


will do thanks for all the help
 
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