[Q][SK17i][FXP117 7.2.0] Battery curve readings

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aidennwitz

Senior Member
Nov 30, 2011
77
19
Hello,

I've been wondering if it's possible to recalibrate how the system reads the remaining battery charge. I'm using Rage 2.8 kernel for FXP and battery life is very good (over 30h with moderate HSDPA youtube streaming, browsing etc.), but what bugs me is that it goes from 100% to 80% extremely fast, then it slows down as it reaches 0%, it can hang on 1% for an hour before it finally shuts down.

I'd like it to be somewhat linear (even if the real physical battery discharge cycle is not linear), is it possible?

Cheers!
 

Someguyfromhell

Senior Member
Feb 2, 2012
4,148
1,828
Hello,

I've been wondering if it's possible to recalibrate how the system reads the remaining battery charge. I'm using Rage 2.8 kernel for FXP and battery life is very good (over 30h with moderate HSDPA youtube streaming, browsing etc.), but what bugs me is that it goes from 100% to 80% extremely fast, then it slows down as it reaches 0%, it can hang on 1% for an hour before it finally shuts down.

I'd like it to be somewhat linear (even if the real physical battery discharge cycle is not linear), is it possible?

Cheers!

Depends how you and other apps really use the phone.
 

aidennwitz

Senior Member
Nov 30, 2011
77
19
I've done idle testing with screen off and no apps, the drain is simply faster at the beginning after charging and later slows down to the point where streaming youtube "eats" less power than idling at 99%. I'm not saying it really does that (because it's impossible), it's just that (I guess) the physical battery discharge curve is like this, but that doesn't really help me at all with estimating how much time I have left.

I may be wrong, but I've tested this twice now (going from 100% to 0%) and it's always faster in the beginning completely regardless of what I'm doing with the phone.
 

schmolch

Senior Member
Nov 27, 2010
291
41
I dont want to **** on the cake but if you care about battery-life you should not use a CM-rom. I used CM-7.2 for 6 months and now switched to a stock-based rom (Spartan). The result is twice the battery-life. CM's battery consumption is horrible especially when the phone is idle. I used to lose 20% during 8h of airplane mode. Now i lose 1-2% without airplane-mode.
 

aidennwitz

Senior Member
Nov 30, 2011
77
19
Actually, the battery life is just fine for me. I agree, pure CM 7.2.0 drains the battery like there's no tomorrow, but Rage kernel alleviates that by a lot.

The reason I don't use official rom mods is that I like CM a lot, and while battery life could get some more love from the devs it's certainly not that bad, especially with Rage kernel. 30h+ with normal usage, internet, browsing, youtube etc. isn't that bad.

My problem is not that the battery is drained fast, but that the percentage display goes down unevenly regardless of usage. Let's say we compare idle to idle, no airplane mode, no background apps. When the percentage is at 99% it goes down about 5% in an hour (I didn't measure it with a timer, but it's a good estimate), while when the percentage is at 20% it goes down about 1-2% in an hour.
 
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BlackArtsInc

Senior Member
Apr 26, 2012
773
77
Athens
Here s an also weird graph!
Stock Rom .62 rooted.
Check the vertical drops!

h ttp:// img.tapatalk.com/8ded9580-228b-a194.jpg

No problems.Just weird.

Sent from one of my 4 iPads.
 

aidennwitz

Senior Member
Nov 30, 2011
77
19
Ok, after deleting battery logs after fully charging the phone (although I don't know whether it was this or something else, maybe it just needed three charges) I got a linear discharge curve. Also, now it turns off at 2%.

BTW battery life on CM 7.2.0 - this time (with LAGLESS governor) it got the phone to 59 hours, which I think is really good enough. Rage kernel FTW. Of course, with LAGLESS and stock rom it'd probably reach over 70. Still, I don't need that much, and CM is great. :)

-- edit --

After another change (switching to 2G when data transmission isn't needed) the phone eats 0.6% battery per hour. Now I really don't need stock. :D
 
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