you need something like battery doctor from the app store, it kills the many many apps that you've got running but don't know about, and encourages you to re-charge your battery properly. you can also buy a battery upgrade as the ones that come with HTC's (as with most phones) aren't as good as they could be. an app to turn down the brightness on the screen should make a bit of difference too (as well as sopping your phone from dazzling you at night)......now how do u keep your htc battery life good cos mines terrible....
This is what you need!!!!
http://www.ebay.co.uk/itm/3X-1500ma...ultDomain_3&hash=item415fbff5e2#ht_2449wt_973