Livre d'Or

I don't have much useful advice, I'm afraid, but I was having terrible trouble with battery life on my (now I think five-year-old) Samsung Galaxy S smartphone - so I turned off the wifi except for specific times when I need it, and now it usually lasts a couple of days at a time. I don't know exactly what you're doing with your phone, and if you're really relying on the smartphone always-connected functions, it obviously won't help, but turning off Bluetooth and wifi and 3G if you aren't using them constantly will save a lot of battery.

Also, a lot of devices these days will show you what is draining the battery - I had a few days where my new tablet was running totally flat within four hours if left unplugged, and managed to identify that one of my game apps was for some reason sucking up enormous amounts of power if left running in the background.

Anyway: my experiences, just in case they might be helpful.