[Galaxy S 5 Android Development (Snapdragon)] chaoscreater:
I've recently switched from a stock ROM (XXU1ANE2) to this on my i900I.

Have flashed the ANG3 bootloader and ANG2 modem for my i900I and using the XXU1ANJ1 stock kernel for i900F, everything is running well but it feels like this ROM drains my battery a lot quicker than on the stock ROM. I have the exact same apps installed and applied the same settings, everything is consistent. The only thing that's different is the difference in the bootloader, modem and this custom ROM.

I've done a lot of testing over the last few days with BetterBatteryStats, Amplify, Greenify, Wakelock Detector and Battery Stats Pro Plus and found nothing wrong. No unnecessary wakelocks, nothing out of the ordinary and the device is in deep sleep 99% of the time.

The only thing I found is the "PowerManagerService.Display", which is a Kernel related wakelock and apparently is also the placeholder for partial wakelocks. Again, I have the exact same apps and settings applied to this ROM as I did to my stock ROM, everything is consistent. None of the apps I use hold any wakelocks for longer than 5s, this is consistent across BetterBatteryStats, Battery Stats Pro Plus and Wakelock Detector.

When I go to sleep at night, the device is idle for 8.5 hours. Airplane mode isn't enabled but everything is turned off. The battery drops from 100% to 98% or 97%. Even though 3% drop over the course of 8.5 hours isn't a big deal, but compared to the stock ROM I was using, it's bad. On the stock ROM, battery drops 1% after 15 hours, that's the average measurement I've taken. When I'm using the phone extensively, it drops 1% every 15~20 minutes on the stock ROM. On this ROM however, battery drops 1% every 6 minutes on extensive use. By extensive, I mean browsing the web with 4G enabled, chatting on Skype, etc. Everything I do is the same as I did when I was still using the stock ROM, I make sure to carry out my testings consistently.

I have tried different kernels and it seems the modded stock kernel for i900I:

"Modded Stock Kernel (for the T/I/W8/L/S models and G900F/M with old bootloader)"

Drains battery faster than using the kernel for i900F (XXU1ANJ1). Therefore, I think the underlying battery drain issue is caused by the kernel, but possibly with the ROM itself as well.

I think I'm gonna go back to the stock ROM (XXU1ANE2) with the ANE2 bootloader and modem. It runs so much better on my i900I (in terms of battery life). If you debloat the stock ROM then it's just as fast as this ROM. I've already tried to disable a lot of unnecessary services and system apps such as NFC, Fused Location etc. Everything is turned off in my testing with very VERY minimal usage, yet the phone drains faster for some reason.

BTW, the Xposed module "ProtectedApps" worked for me on the stock ROM, but on this ROM it caused my phone to get stuck in a bootloop. Took me ages to troubleshoot, I've had to run Xposed in safe mode multiple times to find out it was this module that was causing it.

I also noticed there's a bug with the Location setting. If you disable it and re-enable it, it always sets itself to High Accuracy instead of what you've chosen.