Looking for a Battery?

My laptop is coming to its brokenness, its battery is going down, what's saddened me is its more than two years old and yet its battery is not doing good already. I have chosen a quite good brand when we bought that hoping its lifespan would go long, but I think I was wrong because its giving frustration already.

Hope I could easily find an inexpensive but good quality battery for my laptop just like acer batteries where you could find it online on its online catalog. I just hope and pray also that my laptop will still work long time and satisfy me and hubby its owner. :)