[Xiaomi Mi A1 Guides, News, & Discussion] Dornyx:
Hi. I'm quite new in the custom ROMs' space, but custom ROMs are one of the reasons I've bought the Mi A1. One thing that does matter very much to me is battery life, and therefore I'm always looking for the best combination of performance and battery life. That's why I decided to "test" any stable ROM that appears in this forum, to classify them from the best for battery life to the one with the worst battery drain.

TESTING CONDITIONS

Follow these testing conditions to share your results with us and give us a better rapresentation of average battery life. I'm still defining testing conditions, but that's what I've came up with:

TEST 0 (legacy): WHOLE DAY WITH TOO MUCH MEDIA

Screen on auto brightness, 35/45% all day long

No double tap to wake or always-on display

Always testing from full 100% charge to 15% charge

Test always starts from around 6.00/7.00 AM and finishes when at 15% battery left

Wi-Fi and 4G always on. Connected on 4G from 8.00 AM to 1.30 PM, Wi-Fi for the time left

GPS and Bluetooth always off

No overclock/underclock/power savings

Google Apps mini package installed

Chrome use in the morning, at launch and at dinner, while YouTube gets me the rest of screen on time in the afternoon

TEST 1: GAMING

20 minutes of Need for Speed No Limits,20 minutes of PUBG Mobile

Screen on manual 50% brigthness

No double tap to wake or always-on display

Always testing with battery between 90% and 20%

Wi-Fi and 4G always on; connected to wi-fi

GPS and Bluetooth off

No overclock/underclock/power savings

Google Apps mini package installed

TEST 2: STAND BY 1

3h of stanby

No double tap to wake or always-on display

Always testing with battery between 90% and 20%

Wi-Fi and 4G always on; connected to wi-fi

GPS and Bluetooth on, no device connected

No overclock/underclock/power savings

Google Apps mini package installed

TEST 3: MEDIA

2h of YouTube

Screen on outo 40% brigthness

No double tap to wake or always-on display

Always testing with battery between 90% and 20%

Wi-Fi and 4G always on; connected to wi-fi

GPS off, Bluetooth on (no device connected)

No overclock/underclock/power savings

Google Apps mini package installed

TEST 0 LEGACY RESULTS

Stock Android One 8.0 + MiNT kernel

Stock Android One 8.0

Resurrection Remix (12/15/218 build) + MiNT kernel

Resurrection Remix (12/15/218 build) + Moun kernel

NitrogenOS (02/05/2018 build) + Moun kernel

Android Open Source Illusion Project (AOSiP) (09/05/2018 build) + Moun kernel

NitrogenOS (02/05/2018 build) + MiNT kernel

dotOS (06/05/2018 build) + MiNT kernel

dotOS (06/05/2018 build) + FrancoKernel r7

dotOS (06/05/2018 build) + MetaPhoenix kernel

dotOS (06/05/2018 build)

CosmicOS (01/05/2018 build) + FrancoKernel r7

CosmicOS (01/05/2018 build)

MY RECOMMENDATIONS:

Resurrection Remix the best of the bunch. Use new builds as the older ones MAY give corrupted persist partition (new ones are totally fine);

Mod edit:- above-mentioned issue was only with one old build of RR, and its been already fixed.

AOSiP the next good one. Has less feature than RR but it's worth it;

NitrogenOS has slightly better battery life than AOSiP and RR, but with fewer customizations;

ROM request closed for now. Schedule may vary based on time available to me: remember that this phone is my daily driver and that I'm alone in testing and publishing data.

The need for more tests and the need to revise the first test may also bring the need to change schedule AND retest some ROMs

P.S.: I'm probably gonna update the topic with just ROMs with their own kernels (no other kernels installed) and then a separate list of kernels. The only thing is that same kernel gives different battery life deltas on different ROMs, so it would be best to try different ROMs with the best kernels for battery life (like top 3 of the kernel list)