[HTC One S] rootrider:
Just a few thoughts on battery life:

- first and most important of all:

Charge your phone until it's fully loaded. Sounds quite simple but isn't that easy. You should know that while charging your phone your LED will turn green as soon as it reaches 100%. But it typically needs another 30 to 60 minutes to charge to the max, usually on an average of +50 to +25 mA. Max charge I can achieve on my device is 4230 mV. After nearly one year of use I still can get pretty close to that, but no longer every time I'm charging. But that's ok.

- second is:

Use available powersave settings on your phone. Usually disabling HTC SmartSync will result into higher battery drain during night time as all connections will stay on. I don't know exactly what's being affected by enabling this feature (I think wifi and mobile date will be turned off and on again, if needed, also cpu will be on a different governor and not scaling up that fast and much) but to my experience I didn't miss any call, any sms, any mail or whatsoever. The device doesn't even feel less snappy at all. It simply still works as it should.

And if you want even more, enable powersave mode in settings -> power. By the time writing this, this feature is part of HTCs Jelly Bean sense UI and no sources for the kernel are available. As a couple of things is hardcoded into that kernel and can't be reliably changed from 'outside', things might change in the future when sources become available. Either to the better or worse in these cases.

- use fast dormancy, if your provider supports it.

Otherwise simply disable that feature. If your provider supports it, fast dormancy will keep you connected to the network at lowest possible power consumption. If not and you've enabled that feature, your phone will always be searching for it at max performance. You can watch your battery draining...

- wifi connections

It's big fun to walk through the streets, finding every wifi spot in your neighbourhood and trying to connect to it, you think? I don't. I want my device to connect only to known spots and have it succesfully logged in there and not wasting power for finding useless connections. So I decided to use tasker for that purpose. A little script just enables wifi search coming close to my home or any other useful location by simply watching my home cell towers nearby. And what's even better, if successfully connected to my home wifi, it simply switches off mobile data, to switch it back on, when I'm leaving home. If you still don't know tasker, search for it on google play and find scripts on it's home page. I won't make this a tasker thread.

- blue tooth connections

If you don't use it, simply switch it off.

- screen on time

Black is beautiful, especially on amoled screens as it consumes less or no power at all. Using black backgrounds and inverted apps you're on the right side. I can't say whether auto brightness or setting brightness manually is more advantageous, it simply depends on your needs.

- the right governor

Choosing the right governor is also important. If you want a most snappy device, look for governors scaling up lightning fast and staying on max speed a little longer than others and scaling down slowly (e.g. interactivex2). But they need a lot of battery power, so they should be preferred for light or moderate use only. If saving battery is most important to you, you should choose a conservative based governor. You'll find some very good descriptions over here at CPU Governors explained.

- find power consuming apps

This is another very important thing. Sometimes apps stay active in the backgruond even if they are not in use. For identifying these you will usually need another additional app that records power consumation or online time. The HTC thing in one word is crap. I'm using android tuners statistic for that, but there are plenty of others for free to be found on google play. To get a right view of the things going on, you should check these statistics after a longer period without loading or switching off/on your device, as they usually reset your statistics.

If you find an app or widget draining your battery above average, check in it's settings if it's possible to set lower refresh intervalls, invert colors or whatever seems useful to you for reducing power drain. And think of using alternative apps if that's not possible or doesn't work the way you want.

Last not least I added a zipfile, showing my battery drain last night for about eight hours. Typically not more than 3%. Between 11 PM to 8 AM.