[Motorola Droid RAZR] Ohmster:
Man you are asking me tough questions because I am satisfied with the battery life, as is. I also know as a nightly, this build will change, constantly, so I "do not setup shop" for heavy tweaking and customizations. Never know when it all has to come down to install fresh, all over again. So, I follow the KISS rule, "Keep It Simple, Stupid!".

If you are getting very bad battery performance, it is NOT this rom causing it. You may just have a bad battery, charger, or just really use the phone a lot. Battery tweaks will yield small, collective performance gains, NOT double the life of your battery.

I have friends on droidxforums that can wring days out of a single battery charge and actually use the phone all the while. But these are not "average people" like myself and many others.They wipe and redo their phones every day, sometimes more than once, and eat it like sweet breakfast cereal. I would choke on a diet like that. :p

...sigh. The one I know of that will wring the most possible life out of your battery is also the most dangerous one to use, especially if you are "Going for the Gold". It also adds another layer of complication to the nightly builds when something goes wrong. More to troubleshoot, install, and setup. That would be the JBX Kernel with the Trickster app. In there you have one feature called "Battery Friend". Nice, huh? You can gain a lot more life out of your battery if you start in with the "Expert Adjustments" like CPU speed, timing, voltage, memory timing, voltage, clock rates, etc. These are extremely dangerous things to do. You can easily burn your phone to a crisp with these settings, brick it but good, an no warranty will save you. There are CPU governor settings that affect how hard your CPU is allowed to work, at the cost of performance. This is the only add on I know of where you can safely bump your CPU speed from 1.2 Ghz to 1.3 Ghz. That in itself is pretty neat, and safe, "by itself", but will not save any battery power. I overclocked my phone this way and had no trouble with it and boy was it better. So, I set the governor to "Performance" and anytime I picked up the phone, it was usually locked up, reboot, anything FAR from stable. So, unless you are a real enthusiast, please leave JBX alone. It is a very good kernel. People use it, like it, and have good results. But the detailed things I mentioned are dangerous and should be left to experts and expect crashes.

Trickster by itself is pretty good, but without a custom kernel, you cannot wring that many benefits out of it. Too many numbers to adjust, strange names that are not intuitive. Not so good for the inexperienced. You can reduce your CPU speed with it, slows down the phone, but gives more battery life. At rest lowest speed is 300MHz and that is stock anyway.

Since I am not looking for battery saving measures, they would be slight, each one, and even many of them would not amount to anything significant to me, I am not expert on this. Others may chime in with helpful ideas on

how to improve battery performance

. Things that keep the screen dimmer or darker help, A LOT, limit WiFi and Location, anything that makes the phone transmit power like talking, save battery.

Keeping the screen darker, auto adjusting to the needs of ambient light, gain significant battery power. One of the best apps for this is Custom Auto Brightness. You can really tweak this to save power by setting how much light you need for different room lights in real time. I like and use this free app a lot, but not for Kit Kat. This build has so many things built in and changes so often that putting this kind of work into setting up something so fleeting is pointless to me. I use the auto brightness built in for now. It can all go down the toilet next week, Kit Kat is evolving.

I can give you the list of modules and their descriptions. Browse them. Use the Xposed Framework to download and install some of them, and try them out. Look for stuff made for Kit Kat. Aside from battery power, there is a whole crapload of very, very cool things you can do with these modules. Check out the list and stay tuned, other experts hopefully will give up some of their battery saving techniques in follow up posts. Remember though, we are using NIGHTLY builds so things can change overnight, rendering all you have done, useless. That is why I do not go "nuts" tweaking nightly builds and get them to where I am happy and that is good enough for me until final.

Xposed Module Repository

Go browse modules and install some things you like. Play. Experiment. Have fun. Be amazed. You want my list of modules, sure, you are welcome to see them in the screenshots below. Not that these are "the best" or anything like that, just what I have discovered, use, and like, so far. Your needs and mileage may vary.