I need a bigger battery for our battery-powered grass trimmer. The 2.0 Ah battery that came with it is not big enough for the area I was supposed to tackle tonight. Luckily the trimmer is from a well-known brand, so they have compatible 4.0 and 5.0 Ah batteries available. Maybe I will buy one of those at some point. They have obviously a bit hefty price, but batteries are expensive.