Home Forums Hardware Mac Desktops & Notebooks My Back vs. My 13" MBP

My 13" MBP is still under Apple warranty soooo I don't want to really mess with it, but, the battery is so damn heavy and I bought it so I could leave my 15" at home. (Always have something available and working.) I know it was their selling point that the battery last a long time, but most places I go, I can plug it in. I don't want to pull the battery because:
1) It voids the warranty
2) It will not give me a 'soft landing' if someone trips over the cord (the downside of the magnetic connector), it won't go into that nice 'coma.'

Is there a smaller, lighter battery available for 'cripples' like me? I don't want a macbook air. Considered both very carefully before I bought this, don't want it.