This was posted over at our Thunderbolt Sister site by none other than dlwhtrose, but thought these tips would work for just about anyone with any phone.
Note: This post has been edited to better conform to multiple phone models and styles, so that information specific to any one phone will not be globally applied to others in error. Also, you may or may not choose to implement one or more suggestion below, but that's OK. These are the extremes of many different settings and may not be appropriate for all users, and in all situations.
a. Screen –go to settings/display, turn down Brightness (20-30%), or as an alternative, set to "Automatic Brightness", set Timeout to 30 secs, manually turn off by quickly pushing top button when not using anymore (instead of waiting).
b. GPS – always turn off when not using, and plug into car charger (or car dock if you have one) during extended use
c. Bluetooth – always turn off when not using
d. 4G – always turn off when not using, only use when you need the speed, (the TB will get a toggle either in an update or in app form at some point)
e. Mobile hotspot – always turn off when not using
f. WiFi – turn off when not near a WiFi signal for an extended period of time, but always use when available (faster than 3G, uses less battery), go to settings/wireless & networks/WiFi settings, press menu button and tap Advanced then WiFi Sleep policy and select“Never”, this sounds counter-intuitive, but it actually uses less power because when WiFi sleeps 3G or 4G wakes up to sync, get email, and retrieve other data (WiFi connection disables 3G/4G)
g. Background/wallpaper - use a static image instead of a live wallpaper (but these are cool, so use one if you really want to, they only drain for the short amount of time you are looking at the launcher screens).
h. Window animations – go to settings/sound & display/animation and select“no animations”
i. Keyboard vibration – turn off vibration function (haptic feedback) for when you hit a key (helps with speed too), go to settings/language & keyboard/touch input/text input and uncheck vibrate when typing, you can disable haptic feedback in other areas of the system by going to settings/sound & display
j. Notification lights – unless you really want/need to know when something happens on your phone when you are not looking, go to settings/sound & display/notification flash and uncheck all the boxes
k. Vibration – unless you really want this function, go to settings/sound & display/phone vibrate and turn it off
l. Monitor battery use - go to menu/settings/about phone/battery use, this will show you what is eating the most battery, uninstall troublesome unneeded app, useRunning services widget by going to shortcut/settings (helps identify processes running in the background and foreground).
m. Disable“always-on mobile data”– go to settings/wireless & networks/mobile networks, uncheck “Enable always-on mobile data,”you will still receive emails, texts, and phone calls, as well as internet usage, but it may cause connectivity problems in some third party apps (use manual refresh feature when opening apps to update online data)
n. WiFi and 4G network notifications – go to settings/wireless & networks and uncheck Network notification box (so phone will not constantly scan to look for open networks to tell you about)
o. Background data – if you are not using Google life-management services, go to settings/accounts & sync and uncheck Background data box (so that apps cannot sync, send, and receive data whenever it wants to). Add a homescreen shortcut to quickly toggle this (allows you to update/sync only when you want/need to).
p. Auto-sync – uncheck Auto-sync in settings/accounts & sync, or at least limit what apps are set to sync, it is better to manually sync/update/refresh in the app when you open it (set to update at launch), set update/notification frequency (polling schedule), if you do not want to turn off auto sync, just change widget or app update/notification frequency (refresh interval) in settings/accounts & sync to 30 mins or 1-2 hours, or better yet set it to update at launch, useful for Facebook, Twitter, Flickr, news, weather, Google apps, and stocks, be sure to manually sync/back up your contacts every once in a while in case you lose your phone or break it
q. Email – change sync option in settings, set email check frequency to 30 mins or 1 hour, or as items arrive, or better yet set it to never and manually refresh when you want to check/read your email
r. Camera app(s) – make sure they are not running in the background when not in use, exit/close when done
s. Video chat app(s) – make sure they are not running in the background when not in use, exit/close when done
t. Streaming app(s) – make sure they are not running in the background when not in use, exit/close when done, try to limit use or plug into a charger during use if you can
u. Google Talk – press Menu then tap All apps/talk/menu/settings and uncheck automatically sign in, make sure you exit the application by going to menu/more and selecting sign out when you are done (exiting the app by pressing home or back keys will not sign you out), if you want to receive IMs just open the application again
v. Adobe Flash Player – open browser, hit menu key, go to settings/enable plug-ins and set it to“On demand”(this way the browser only loads flash content when instructed to do so)
w. Update apps – hit menu key and to go My Apps to check for updates, even if you have selected“update automatically”because some apps require you to manually install updates (apps often get updated to use less power)
x. Location settings – disable when not needed, go to settings/location & security, uncheck “Use wireless network” and“Use GPS satellites”(box must be checked while you are using Google Maps Navigation), uncheck Geolocation option in apps where it is not really needed
y. Task killer – do not use them, uninstall if you currently have one, can harm phone and consume battery, just use back arrow key to exit apps instead of home key, simply monitor rogue apps instead and uninstall/replace
z. Anti-virus – do not use them, uninstall if you currently have one, only download and use periodically or when you suspect a problem, do not download suspicious apps (check reviews and rating in market first)
aa. Ad blocker – do not use them, uninstall if you currently have one
cc. Delete unnecessary apps – determine which apps you do not need or use anymore and uninstall them, determine which apps you keep are causing the most battery drain and see if a comparable replacement from the market will do better
dd. Home Screen widgets – turn off animations, do not use too many of them (choose them wisely), and delete unnecessary ones, they pull data in the background. At least make the interval/frequency of sync/updates longer for the ones you have. It may be better just to open some apps themselves instead of using the widget. Disable auto-updates on HTC Weather widget or at least set it to every few hours, manually update by tapping update icon on bottom of widget
ee. No service – turn off phone or go into Airplane mode when you are in an area that does not have cell service
Chargers – have them handy at home, at work, and in car, and plug in when available
If all else fails, buy an extended battery or have a spare handy just in case (or a portable battery booster if your battery is non-removable).
I hope this helps some of you. I know that a few of these steps and I am able to get 10-12 hours out of my battery with moderate use.