ok.... some advice:
1) You don't need to turn 3G off unless your phone is constantly polling back and forth between 3G and normal signal. If that's the case you may want to shut off 3G at home and use your wifi if you have a wireless in your house (Trust me, wifi is easier on your phone if you have it because it's so much faster than 3G). When out and about... turn wifi OFF. You do not want it polling for networks constantly unless you're out war driving (And no, I'm not advocating war driving I'm just acknowledging that there are folks who do it.). But really... if you're doing that use a laptop or something. A phone is terrible for it.
2) Widgets!
OMG I never understand why people use so many widgets that auto-update themselves. Pay attention, closely, to what rights your widgets have. For example if you are only using the google calendar your calendar widget does NOT need full internet access or SMS access or access to your SD card or any of that. All it needs is 'read calendar information'. Apps, especially widgets, can chew up battery fast if they have too many rights and if they tend to do stuff in the background. Taking the calendar widget, for example, I use the 'smooth calendar' widget from the android market. It's very simple, very clean and looks great. Additionally it needs no special rights other than read calendar access.... and it's free. Now, most calendar widgets will 'update as needed' this is bad... this means they're constantly checking for updates to your calendar (battery drain, not much but it's there). This widget lets me configure it... you can turn off the 'as needed' which sets it to check for calendar changes every hour instead. Much easier on your battery. This is just an example but take my advice you want to try to set up all your widgets this way. Twitter/Toutier/Plume/Facebook/Weather Widgets all of these are constantly updating and most of them allow you to configure the interval. Make your intervals as long as you comfortably can. I usually keep my twitter app (plume in my case) set to 4 hours. Honestly I don't need to read tweets the second they come in... Facebook I tore off the phone anyway because it's so damn intrusive... I'd tear twitter off too but I do actually use it to read the news, etc (I really only subscribe to a couple twitter sources and most of them are news related). Bottom line: If you can configure a tool that auto-updates set it's interval as long as you comfortably can.
3) Uninstall that task killer OR learn to use it properly.
Killing tasks in Unix is bad. Yes, your phone is running unix (a version of linux actually). Turn off your auto-kill feature, it's draining your battery. Why? Because your phone is just going to re-launch those background apps anyway and it actually chews more juice for it to constantly re-start them than for the os to just put them in sleep mode in the background. If you really want to get rid of them, uninstall them. If they came with the phone? Root it and remove them or install a rom that doesn't have them in it. (I rooted mine to get rid of moxier mail and a whole host of other garbage sprint stuck on my phone). Rooted phones, if you pay attention to what you put on them, generally have much longer battery life than 'out of the box' phones because they don't have all the provider installed bloatware (most of which is auto-updating and everything else in the background). Bottom line: The only time you should kill a task on an android phone is if it has gone haywire and is chewing up more resources than it should or if it was supposed to close but got hung for some reason (make sure you're closing apps properly). This usually doesn't happen and, if it is, you should probably uninstall the app if it does it any kind of regularly. This isn't windows, folks. Leave the tasks alone unless they're broken.
4) Turn down your screen brightness!
(Don't use the autodetect, it's terrible). Keep your screen as dim as is comfortable depending on your localle/lighting/etc. Generally speaking you can comfortably keep the screen at it's very lowest brightness unless you're outside in bright light/sunlight. Bright screens eat batteries for lunch.
5) Turn off Vibrate & use standard ringers where possible!
Honestly... why do you need the phone to vibrate? Unless you are constantly having trouble hearing your ringer/alerts you should have vibrate off unless you have the phone in vibrate only mode for a meeting/movie/whatever. Vibrate mode chews up TONS of battery compared to using a ringer. Most apps that have notifiers default to having a vibrate on them. Turn those off too (I'm looking at you Handcent! GRR). As to ringers? Go with the build in ringers for your phones. Yes, using an MP3 as your ringer is fun... but using them uses a lot more battery than your built in ringtones.
6) Sounds...
Go into your phone settings under sound settings and turn audible touch tones, audible selection, screen lock sounds and haptic feedback off. (this is also another area for vibrate settings, turn vibrate to: Only when in vibrate only)
7) Set your phone timeouts low.
There is no reason to leave your screen on for 2 minutes if you're not using it. I have mine set to 30 seconds. Keyboard lights don't need to be lit if you're not typing (if your phone is rooted there are even .apk's to turn them off completely... I don't because I often use my phone in the dark and need to see the keys but some folks use those because those lights do chew battery power)
8) GPS:
Turn off GPS unless you're using it. ESPECIALLY if you're in a building. GPS chews through battery like crazy when it's hunting for sattelites.
9) Netork Location Service:
I also highly recommend turning off the 'network locations' service that augments GPS unless you're using it. While it doesn't chew as much power there's really no reason to have it turned on unless you're using it.
10) Antivirus software.... ok here's the deal:
- There really aren't any 'viruses' for the android. There are 'social engineering' apps that act like a virus but they can't get on your phone unless you install them.
- READ the permissions any application you are installing is asking for and use common sense before allowing them on your phone if they're asking for hinky rights. Seriously, your barcode scanner does NOT need access to your phone contacts, system logs or what other applications are running on your phone. There are other options that don't ask for that info. Internet access I can understand... it allows the app to search for product matches etc. But there is no need for the other rights (looking at you Bar Code Scanner, go pick up ShopSavvy or another barcode reader that's less invasive.)
- The only way the get on your phone is if you allow them to.
- That being said there's nothing WRONG with anti-virus software for your phone except that it's another TSR that's running constantly in the background slowly chugging away at your battery. Think about whether you really need one or not. A lot of us don't bother with it because we know what we're doing and know how to check what apps want rights for etc. If you're fairly tech savvy and have solid common sense you PROBABLY don't need an antivirus program. If you DO want one do some research and find one who's footprint is fairly light. ALWAYS read user reviews thoroughly and go through several pages to see if anyone is complaining about large battery drain from them before installing them (Really you should do this for any app but especially for these buggers)
11) Internet Prevention where needed/possible:
If you are rooted there are two apps you will ABSOLUTELY want to install
- Droid Wall: Firewall app for your phone that updates your Linux IP Rules in the phone itself to block / allow certain apps access to the internet. If you have apps that you simply must have that also have internet access but don't really need it (games, sms programs, etc) you can use droidwall to shut off their access to the internet, which will reduce their battery consumption, especially the ones running constantly like SMS programs, etc)
- Addfree Android: This is a nice app that updates your phone's host file (if you don't know what one is go look it up on wikipedia). What this does is download a host file to your android that blocks (by changing their route to 127.0.0.1) known advertizer sites. What this does is prevent the adds in many programs from displaying/downloading which, again, reduces bandwith they use on your internet / 3G thus reducing their battery drain. This is great because there are lots of programs that NEED internet access that also pull adds down (web browsers, social apps like plume/facebook/twitter/handcent/etc).
12) Proper Battery Maintenanc/Use:
The biggest and best thing to do though is about once or twice a month totally drain your phone and recharge it to 100% This will help keep it at optimum performance. Contrary to what many vendors will tell you lithium-ion batteries (which is what's in our phones) have a sort of 'memory' which gets all mixed up over time as it charges and dumps. Also, don't keep the phone plugged into a charger all the time. USE your battery. Leaving the phone plugged in constantly actually winds up 'overcharging' your battery and can reduce it's lifespan. You are better off charging your phone up then taking it off and using it until it's low and needs to be charged again than keeping it on a charger constantly. (Tons of people make this mistake)
The best way to 'reset' your battery is as follows:
- Use the phone until it *dies* and turns itself off
- Turn the phone back on, it will come up, run for a moment or two then shut itself back off. Do this step once, maybe twice.
- Leave the phone off and plug it into the wall jack charger (not the usb charger for your PC) and walk away, leave it alone, let it charge to 100%. I know, you feel naked without it. Go relax and have fun and remember that you do not need to be 'connected' every living moment.
- Once it's fully charged use as normal.
- You should immediately notice that the battery is lasting longer than it was.
**** NOTE ***** DO NOT OVERCHARGE YOUR BATTERY!!!!
There are several posts around the web lately telling people to charge their phone to 100% then unplug it then plug it back in and charge it more... then repeat this as much as 2 or 3 times. Do NOT do this. Yes, in the SHORT term you will get a bit more life out of the battery but over time you will burn it out much faster and wind up having to replace the battery way more often. You even risk causing the battery to burn up which could cause it to 'melt down' and dump power faster than normal which could, potentially, damage your phone. Don't do it.
Here's a pretty decent article about it. There's a LOT more to it than that but this gives you a nice 'nutshell'. If you're really interested in learning more knock yourself out. It's a pretty fascinating subject.
Lastly:
Close apps properly. Use your "Back" button (the back arrow beside the home key on most androids) to close them rather than the home button. The home button will almost always leave apps running in the background while the 'back' button usually closes them unless they are a 'resident' app that stays open in the background for some reason. If you like you can use a task manager to see this in action and, if an app isn't closing properly after you're done with it, you can kill it.... keep in mind: Things like Market tend to stay open sometimes because they're checking for updates for your apps. Give them a bit to close before panicking and killing a task (see up above about task killers) remember that, in general, killing tasks in linux is BAD. All those posts you see around the web about how wonderful task killers are are from people who do NOT understand how the linux OS works. It's bad advice. Don't follow it. Task killers are NOT helping you unless you use them properly. (Can't really emphasize this one enough).
Wondering how much this helps?
I'm on a Samsung Moment running Android 2.2.1 Rooted
I get about 25-30 hours of life out of my phone on a single charge with light-to-moderate use. Before I rooted it a couple days back I got about 16-18 hours out of it on a single charge when it was on the stock 2.1-1 android version. My wife has the exact same phone on the stock android 2.1-1 build that Sprint provided before discontinuing support and doesn't follow most of the above guides.... she is lucky to get 8-12 hours.