[HTC Sensation] n1ghtl1fe:
*Disclaimer* This is all from a personal experience and testing/research from a long time android user, what I have discovered over time and has helped me and some friends. This will work whether your rooted OR not. I kept it as basic as I can so everyone can benefit. If you dont like what you read and disagree, or want to add something PM me, Ill change/add and give credit to you. Hopefully, this can grow with the community.

*Rooted Section Will be Added*

*When I charge my battery I usually drain it all the way down or as much as i can (around 20% left) then charge plugged in till green, then power down and charge for another hour or so. Not sure if this matters or not but seems to help me out try it!*

This guide will help you if your rooted or non-rooted, all the apps I talk about I honestly have no ties to the devs. I don't use any SUPER AWESOME AMAZING BATTERY SAVER 5000 apps or anything like that. Those mostly just turn ur radios off and on and kill apps in the background. In my experience a lot of them cause syncing issues with my e-mail and other notifications. I like to receive my information instantly not have an app waiting for me to turn my screen on to check for updates.

About my personal setup: Basically, I want my phone to last me all day but still perform well with a heavy use, WITHOUT needing to constantly change settings to save battery. With what I have here Im able to keep my Sensation running for a full day of moderate-heavy use (7:30am to around 10pm) with its STOCK battery (Did damn well on my Evo 4G too). Days of very minor use Ive gone into the second day with 60% + battery. Yes, I use all my home screens and have a good amount of widgets, I love sense and its widgets. I play games, surf the web, do a lot of texting, listen to a lot of music, decent amount of fbing and email, usually take a few pictures a day. Half my day is wifi/other is mobile data.

Here goes the real basics, mostly common sense here not trying to insult anyone. Feel free to browse thru it quick (green text) if your not totally new to the android scene, whats after it will be a good read for noobs and vets.

*I use the power control widget, make getting to a lot of settings quicker. Why waste battery digging thru menus?*

Basics:

-Screen brightness: (duh :) ) these pretty screens eat battery brighter=quicker drain naturally and from my experience leaving it on Auto Brightness kills more battery too. Each time your phone pulls information from the sensor to decide on how bright it should adjust itself too.

-GPS: If GPS is on it should not effect battery unless an app is using it and you see the GPS icon on your notification bar. I noticed a very slight increase in mA discharge when i had it enabled, to be safe leave it off if you dont use it extremely frequently.

Location thru mobile networks: Not to hard on battery. I leave mine on it does add drain but it takes away from my weather widgets updating when Im traveling.

-Bluetooth: Moderate battery drain. I honestly don't use it at all myself but if you do try your best to keep it off when not in use.

-Wifi: Android has gotten a lot better at managing wifi over the past few years. It doesn't drain that bad on battery and it shuts off/on periodically on its own when screen is off depending on whats using it.

Google Back-Up: Takes a little juice here and there no biggie. I dont use it just because I like to fresh install my apps when I try a new rom, run into less problems that way.

2G/3G/4G: This varies phone to phone, the slower speed the better battery life. If you know your not going to be using 4G for a while turn it off. I leave mine on 4G or wifi all day with my sensation. When I had Sprint and my Evo I would leave it off most of the time. Depending on your carrier and how their data works this is a big one. T-Mobile seems to handle well, Sprint and Verizon's 4G Ive seen eat an insane amount of battery.

Sync/Background Data: I lumped them together because sync is pretty much reliant on background data. These kill a lot of your battery in general. It syncs your apps (email, facebook, google data, contacts, etc.), the periodic checks your apps do to check for and download new emails and notifications, using background data (data still transmits when screens off). I always leave these on and still manage great battery life, I like things instant if I wanted to wait Id just wait till i got in front of a PC. Sync and Background data are the settings most battery saving apps control because they really can help your battery if you turn it off. You can control what core apps sync in settings>accounts and sync. Or the power widget that 95% of android phones have has it on there. I recommend minimizing the amount of apps you allow background data with, example: WeatherBug first launch it asks if it can automatically update itself in the background for apps were thats not necessary hit no.

Radio/Airplane Mode: Pretty self explanatory, turns off your connection to your wireless provider. No point in ever turning it off in my eyes, your phones no longer a phone.

What has really helped me with my battery life (non-basics):

There is a lot to be said when it comes down to 2.2+ android phones and whether they need a task killer anymore or not. Since Ive had a lot of android phones and a few now that are 2.2+ Ive done a lot of testing. I usually go about a 2 weeks on one idea or new task killer and keep a close eye on battery drainage using Battery Monitor Widget, free app in the market. It tells you exactly how much of your battery is being drained without killing battery itself. Each phone/rom settles at a different average mA lower the better. In my experience if I can keep my phone anywhere under 100mA when idle im doing good. This held true on both the Evo 4G and my Sensation. Some ASOP roms i could get down to the 30's but for sense under 100mA is good. Keep in mind you will get the occasionally spike here and there its just android and/or apps in the background. You can view the a chart of the battery data in Battery Monitor.

Instead of boring you guys with each task killer Ive used and its results, Ill just get down to what I found out in the end.

Basically, the way android 2.2+ works it really isn't necessary to run a task killer it does a decent job removing apps from memory when you need more memory. But at the same time I found running a task killer periodically (BUT not killing frequently used apps) results in a lower average mA drain leading to overall better battery life.

The best application I have used has to go Automatic Task Killer , trust me Ive used a lot from the top free ones to a few of the more popular paid ones. What this task killer does is kill a selection of apps you allow it too every time your phones screen shuts off and goes idle. On Automatic Task Killer's first boot your shown a screen of every application that could at some point run in the background on your phone. This part sucks a little bit but it is worth it, you need to select which of the apps you want to allow it to kill automatically. It does not kill foreground apps the ones you currently have open on the screen aka a browser or a game. Example your playing NFS: Shift and your boss walks by so you quickly pause and hit the power button turning off the screen, next time you turn the screen on it will kill all other allowed background apps but your game will still be up front and center.

Now the trick is to go thru and set it to kill apps you know your phone won't automatically just restart or you don't use 90% of the time. So don't select things like Dialer, Contacts, Clock, Calendar, Messages or apps you constantly use/check such as a third party SMS app or your main E-Mail Client or third party keyboards (various by person and what you use most). Letting the app automatically kill those is just going to lead to worse battery life because your phone will just restart it each time leading to more CPU cycles (not what you want and part of the reason some consider task killers bad things).

Also, when using any task killer and killing the proper apps sense seems runs smoother, a big deal with sense 3.0.

Re-calibrate Battery: After you flash a new rom or start using a new battery, you should use your recovery (CWM or other) to Wipe Battery Stats. Before you do this make sure your battery is at 100% and has been on the charger for over an hour with the fully charged green led on. This will allow your device to better drain your battery and can really help battery life.

So hopefully with a little messing around you can get a good setup where your phone lasts you all day without having to constantly keep changing settings and watching your battery life. All while everything stays syncing and instant. Hope this helps!

Thanks to people who have contributed:

-JadeSoturi