The last weekend camp I went on, my phone (HTC Legend) was dead well before the end despite hardly using it and I generally got sick of having to charge every evening so when I got my new phone I looked for one with better battery life but on the reviews, they all said the same - charge every night. So I decided I'd try optimising the setup to get some more and this is what I've got so far. With reasonable use using the internet, email, some calls and texts I'm getting 2 days easily. I'd estimate 4-5 days or longer if it was just on standby for emergency use. New phone is HTC Explorer. (Android)
1/ I've installed the JuiceDefenderPlus app (£1.99) which turns off the wifi etc. when it's not needed. If you don't want to pay, the free version is almost as good (use the 'agressive' profile). This makes a huge difference and I don't know why Android doesn't do a lot of this itself. My current settings are:
Mobile data: enabled (will turn it off when it can)
WiFi: enabled (will turn it off when it can)
Options auto disable, wifi preferred
Schedule: enabled (1h, 1m) so I can quickly flick on the screen and see if there are any emails to read
Night: enabled (22:00->06:00)
2/ I've avoided the use of widgets. The only one I'm using is a free clock (DIGI Clock Widget) which doesn't include loacation information, just the time. I'm pretty sure that monitoring your location uses quite a bit of power and isn't really necessary.
3/ Maps - Try not to use it. If you do it seems to start up a background process that continually monitors where you are so that next time you use Maps it is ready and doesn't need to search. If you must use it, afterwards go into 'Manage applications' and clear all data for Maps which will get rid of it. Force stop won't work - it will respawn.
4/ Settings->Power->Fastboot should be off. If left on, it stops the phone from sleeping properly so it can start up quicker. For the sake of a few seconds wait at startup I don't think it's worth it.
5/ Settings->Location turn off WiFi and GPS. Again, you don't need to know where you are that accurately and neither does anyone else. Turn them on if/when you really need them but by default leave them off.
Hope that helps someone and would like to hear any further hints/tips to extend the battery life even further.