[Nexus S General] ben.selinger:
This thread is to discus extremely poor battery life on the Nexus S. When we say extremely poor, we mean averaging <24 hours per charge at idle.

After much research I think it's safe to say that some of us are experiencing extremely poor or contrarily, extremely good battery life and no one seems to have an explanation. I'm hoping this thread will find the answer.

The issue:

Many NS users are experiencing extremely poor battery life regardless of:

Rom installed

Apps installed

Installation method

Battery used

Charging method/battery training

Phone usage

Power configuration/tweaks

When we say "extremely poor" we mean <24 hours at idle, but many users are getting less than 8h/C at idle.

I personally have tested this against several ROMS both GB and ICS. We all see slightly better battery performance with GB ROMS, but never greater than 24h/charge.

My ROM history:

Tested the following ROMS for 4 days each, following the same installation procedure each time.

CM7 (nightly/stable) - ~15h/C@idle

CM9 - ~13h/C@idle

CyberGR .v4.5 - ~11h/C@idle

CyberGR .v5.0 - ~11h/C@idle

Installation method:

Wipe battery stats

Wipe data/factory reset and wipe cache partition

Flash Dalvik-wiper.zip and wipe Dalvik Cache

Wipe data/factory reset and wipe cache partition again

Format /system/data/cache/boot/sdcard

Flash ROM

Flash Gapps if applicable (CyberGR comes with Gapps installed)

I was running an AUCKF1 Radio for all tests. I did try a few other radio's but did not see any noticeable increase in battery life *edit-flashed XXXKB3 and may have increased my idle time by 6x? still testing*

I've also never personally seen an NS get >24h/C, and I've deployed >40 of them to customers. I've only ever heard of >24h/C here on the forums where it seems quite common.

I've seen reports of users flashing the OTA automatically or manually, and some experience <8h/C@idle while others see >3d/C@idle. I've also tested the OTA and never saw better than 13h/C@idle.

So, we're trying to find the common denominator between those with good battery performance vs. those with poor performance.

Suspects:

Android OS is almost always reported to be active/awake for at least 50% of the time, even at idle on a brand new clean install. It is always the highest consumer of battery, always keeps the CPU awake.

I propose the following test:

Regardless of your setup, if you are experiencing >2d/C@idle or with use, please post the following:

Phone model (ie: i9020a, i9020t...)

ROM

Radio version

Installation method

Screenshot of your battery monitor from a full charge over a minimum of 10 hours.

Screenshot of your battery use by application/service (we notice that Android OS seems to be the culprit in most cases of poor performance)

For those getting <1d/C@idle, please do the following and then post the same as above:

Note: This should be done overnight.

Follow the above flash instructions and flash whatever ROM you please.

Reboot to recovery and wipe your battery stats.

Power off your handset and give it a full charge while powered off.

On first reboot, sign into a single Google account but do not restore your apps/backups and disable Google sync.

Do not install any additional applications.

Enable wifi/bt/gps/data/sync and associate to a wireless network

Do not modify any power settings.

Leave your handset to idle overnight for at least 8 hours without touching anything.

In the morning, take a screenshot of your battery use as well as battery use by application/service.

Post Phone model, ROM, Radio version, Carrier, and Screenshots.

I recognize that there is some argument about how fast your battery will re-train itself after wiping battery stats. In my experience the training seems to be optimal after 1 full charge to full discharge cycle, but ultimately I've never seen further training result in >24h/C. Someone please let me know if there's a more accurate way to test this? Maybe we shouldn't be wiping battery stats at all?