Does GrapheneOS also need to optimize the battery for the first few days?

nolongerhuman

I’m having issues with my Pixel 8 on stock OS where it drains about 2.5-3% battery per hour while idle. That’s in airplane mode, no sim, and only using wifi. Most adaptive settings are also off and no apps running in the background.

Because of that I tried to install GrapheneOS, its on Android 16 and I haven’t installed anything on it yet, just fresh after setup. Even with that, I can still observer the same drain, about 2-3% per hour while idle and no apps installed.

It has 300 cycles and is running Android 16, January update, Nov for Play Services before I installed GrapheneOS.

Watermelon

As far as I know, the “optimization” you're talking about is Android doing JIT (just in time) compilation of the Dalvik bytecode in all apps, and creating profiles to know which parts are the “hot” parts in order to AOT (ahead of time) compile them.

Both profiling and JIT compilation of Dalvik bytecode is disabled on GrapheneOS. After certain OS updates (not all of them), GrapheneOS may need to recompile apps, so it uses a combination of AOT compiled code together with interpretation of the non-compiled parts without JIT compiling these parts, and there's a visible notification showing a progress bar of fully AOT compiling all apps. It's shown to you and not hidden, and once it's done, it's done until the next OS update. When you install/update apps, they're fully AOT compiled before the app install/update completes (this causes app installs/updates to be lengthier on GrapheneOS, especially some apps that contain a lot of Dalvik bytecode compared to other apps).

nolongerhuman

Watermelon

If I remember correctly, there’s an update just after I installed and setup GrapheneOS. There’s no notification or progress bar anymore so I’m wondering if it should still consume that amount of battery in a short time.

Watermelon

nolongerhuman I think it's possible for increased battery use in the first two minutes or so after you unlock your device the first time after an update. The OS still does things after updates besides app optimization. But it really shouldn't take more than a minute or two.

The update you're talking about could be the opt-in to security preview releases. I believe the WebUSB installer always installs the open source releases, so when you opt into security previews it immediately begins updating to it.