how much time your cell battery can giving backup?

Generally it could hardly reach the time mentioned in the Instructions, it is different if the cell phones belong to the same company, it deponds on the use frequency.

Well, I use Sunsang and Sony Ericsson cells. I have to say I prefer the former one, because it has almost everything I want in a cell phone. But as for the Sony Ericsson, I have no comment on its design or sound quality, cuz it's pretty cool. But the battery is not that good and serviceable. Often when I make and receive calls too often, the battery can run out very soon. It's bad for u to always have to check out the battery at any minute when you are making long-time calls to some important persons,right? It brings a lot of inconvenience.

i think caring for your battery life depends on the user...usually a battery has 5years life guarantee but if the user overcharge it often...it shortens the years you will be able to use the battery.

Nokia certainly gave a good service regarding battery. I am also a Nokia user and I am much satisfied.