[Schnee100]

My battery is starting to give me trouble. Doesn't last long at all. It is orig. 9780. how long is life of such a battery? is it ok to replace with a non-original but good one?

[BergerKing]

Lifespan isn't as much dictated by time, but rather charging cycles. Over two years, how many times have you charged the phone? If you come up with 400 to say, 600 times, rest assured your battery has been through the wringer.

I would recommend you use the official battery, if at all possible, as the battery contains circuitry that regulates the charging of your phone. If it is a quality replacement, say Seidio or a Megan, or another reputable brand, those can be OK, but beware of generics, some of them can damage your phone.

[Schnee100]

In terms of a non-original battery....have you ever heard of "Touch Mobility"?

[BergerKing]

Not personally familiar with them, no.