The liquid mini runs on 1300mah battery which gives very less battery life.so in order to extend the battery life of the phone,what you need is a battery saver app.so here are the apps that you'll need.

1.JUICE DEFENDER This battery saver is most famous of all battery saver app,you'll have options to select and profiles for battery saving like extreme,balanced,aggressive,custom etc.if you use a rooted phone then this app is for you.

2.BATTERY DOCTOR This is also a nice app that can help you saving your power,its got various charging options,smart saving mode etc Download links for juice defender and battery doctor
JUICE DEFENDER APK:http://www.mediafire.com/?99lins0tpplmc11
BATTERY DOCTOR APK:http://www.mediafire.com/?ua636ybv527271z