[EVO 4G Android Development] laydros:
I've been watching battery life comments through this thread and the nightly thread since the first nightly, but I haven't said much (maybe anything) about it yet.

First, I will agree battery life it isn't great. I've been able to use this as my daily driver since the first nightly, but I typically get it on the charger once or twice during the day. Because micro USB cables are cheap on Amazon, and I work at a desk and drive a car, it isn't a problem for me. It has gotten better, but Cyanogen mentioned that some tweaks still need to be made.

Second, it bears repeating that the meters are not right.

- For one thing, when you take the phone off the charger with a green light, it may be in the low 90s for battery %. This is a function of the EVO, and has been mentioned many many times.

- Additionally you will need to calibrate the battery stats. It is also listed many places but get to 100% (not green light, use OS Monitor or something to check for full 100%) then deplete all the way, then charge back to 100%. This will get an initial calibration, and within a couple of days things will be about right. But even after this initial calibration they aren't quite there.

- The meters that show what has been using the battery are wrong. We probably are still getting that calculated based off N1 hardware or something. When you see that the screen has been using 90% of the battery, that isn't correct. Yes the rest of the stuff probably uses less than it did in 2.1 (that speed bump you see from JIT is going to help the CPU use much less juice too), but this meter will be updated once Cyanogen can get better hardware info.

Third point, and I'll get off my soap box. I have read so many posts about battery life, but I really don't think I have seen anyone mention this part.... It really seems to me like battery life with the screen off (3G on, sync on, BT off) is WAY BETTER than stock. It is the awake time that battery life is worse. Part of this is that the screen is using more juice relative to the rest of the hardware, but it may also speak to CPU scaling or something else being particularly good or bad. Either it is so good that this battery hogging rom just sips when on standby, or so bad that the ROM is generally very battery efficient, but eats it up when ramped up for usage. I dunno, but I noticed it. There certainly doesn't seem to be an always awake bug going on.

Generally I think battery life isn't too bad for something with this level of customization. I know most people realize this, and not to cut down other rom devs, but for the few that don't know, this ROM is nothing like anything else we have for the EVO so far. It is (gross simplification) taking the stock Android that Google provides, and then tweaking it from scratch to work with the EVO. All the other ROMS out there are based on the work HTC did to get it to work on the EVO, and then tweaked. Most of the ROMs you use from now on will at least in part borrow from the work Cyanogen and Team Douche are doing now. This is hard stuff. It took HTC a lot of work to get these things right, and the people working on this right now are having to do a lot of the same things.