Custom ROMs and battery

**ulnek** · 12-08-2012, 09:49 PM

can rooting and getting a custom rom give me better battery life? if so, which one(s) will do it? thanks for the help.

**Paul627g** · 12-08-2012, 10:19 PM

Custom ROMs in themselves normally don't yield much better battery life. The key to battery life is within the kernel that runs along with the ROM/OS.

I recommend something along the lines of Trinity or Lean Kernel for best battery life.

**Patrick Schroedl** · 12-09-2012, 07:47 AM

There was a thread in this forum about two weeks ago asking similar questions; there are certainly more of them around and searching for them should yield plenty of results. The thread I mentioned can be found here, but I'll quote two posts from that thread (by myself and the ever-helpful 2defmouze) as well.

Originally Posted by 2defmouze

Kernel and kernel settings are going to have more effect on battery life.. the ROM has little to no effect, really.

EDIT: as well as the usual factors like signal strength, etc...

Originally Posted by Lumenii

Going off of what 2def said, the following things will be your best friend when you need longer battery life:

CPU clock speed (underclocking)
CPU voltage (undervolting)
Signal management (LTE toggle, Airplane mode)

Fewer clock cycles per second mean less power used, a lower voltage level means less power used per clock cycle and smart signal management is simply the most efficient method of power conservation for LTE-enabled devices.

There is one exception to the typically negligible impact that ROMs have on battery life. If the ROM you have flashed has a bug, or is poorly written, to the effect that it prevents the device from going into its 'deep sleep' mode when not in use, your battery will not last nearly as long. Re-downloading the ROM, checking the MD5 hash, and then re-flashing it would solve that problem. I should note, however, that the Android community devs are usually very good about preventing these issues, though it does happen occasionally.

Edit: I second Paul's recommendation on Leankernel. I've used it for a long time.

**ulnek** · 12-09-2012, 09:34 PM

ah ok. i don't really know anything about rooting and i'm afraid i'm going to ruin my phone and it would stop working. i just need a bit more battery life though so i'm looking into it.

**Patrick Schroedl** · 12-10-2012, 01:30 AM

Originally Posted by ulnek

ah ok. i don't really know anything about rooting and i'm afraid i'm going to ruin my phone and it would stop working. i just need a bit more battery life though so i'm looking into it.

Don't be too afraid -- once you get going, it all starts to make sense really quickly. And on the off chance something does go wrong, the AC community is extremely helpful.

**bbudnick5001** · 12-10-2012, 03:44 AM

[GUIDE] Don't Panic: The Hitchhiker's Guide to the Galaxy Nexus

^This is written very well and should answer a ton of questions. It did for me!

Sent from my Galaxy Nexus using Android Central Forums

**sr2012** · 12-24-2012, 08:59 AM

Underclocking definitely cools down my HTC One X for sure... Now that it is summer in the Southern Hemisphere here...

**MRW1215** · 12-26-2012, 08:25 AM

I've had disappointing battery life since I was on the official AOKP 4.1 builds, and I can't quite figure it out. Yesterday, I was down to half my battery, and when I looked at my screen on time in the settings, it said my screen had only been on for about 24 minutes, total. Which would mean that, on a full charge, I'd get about 48 minutes of screen on time... That seems pretty bad, to me.

Currently, I'm on the DizzyThermal AOKP 4.2 builds, and I've been using franco's kernel releases (I even have the franco kernel app, and I have it set to run in "BeastlyBattery" mode).

I wish I could figure out why my battery seems to not give me much use. I feel like I should be getting at least 2 hours of screen on time. 48 minutes is not a lot at all.

**myriad46** · 12-28-2012, 03:19 PM

Originally Posted by MRW1215

I've had disappointing battery life since I was on the official AOKP 4.1 builds, and I can't quite figure it out. Yesterday, I was down to half my battery, and when I looked at my screen on time in the settings, it said my screen had only been on for about 24 minutes, total. Which would mean that, on a full charge, I'd get about 48 minutes of screen on time... That seems pretty bad, to me.

Currently, I'm on the DizzyThermal AOKP 4.2 builds, and I've been using franco's kernel releases (I even have the franco kernel app, and I have it set to run in "BeastlyBattery" mode).

I wish I could figure out why my battery seems to not give me much use. I feel like I should be getting at least 2 hours of screen on time. 48 minutes is not a lot at all.

What else is in that list of battery usage, besides "Display". Something else is chewing up your battery. Also, what was your total time on battery? If your phone hasn't been plugged in for 30 hours, it doesn't matter how long your screen has been on.

In my experience with various roms and this phone, your idle time can be affected significantly with Roms and Kernels, but screen on time, and the effects of heavy data use, are never going to change much.

**MRW1215** · 12-28-2012, 03:32 PM

Well, I realized I constantly had GPS on, and when I turned that off, my battery has been a little better. I can get about an hour of screen on time and be down to 25-ish percent left. Still seems like I should be able to get a little more out of it than that, but I'm not really sure what else to look at. I only have a handful of things syncing from my Google account, so that shouldn't be TOO much of an issue. At the moment, my battery settings show:

9 hours and 7 minutes on battery
screen 45% (56 minutes)
Chrome 12%
phone idle 12%
cell standby 9%
Android OS 8%
Maps 5%
Android system 3%
Beautiful Widgets 2%
Mediaserver 2%
Amazon Appstore 2%