I was a little reserved at first, but Im happy with the 30 that I spent. The batteries look cool, too.: Although a AAA option would have been a nice touch-but Apple obviously designed this to work with its wireless accessories - to add a green option to all the batteries that you will be using. More
The D31A, D31T and D31M below are new models. D31A connectors are SAE automotive-style top posts. See Model D31A top-view more info here. The D31-series batteries are Optimas largest. In addition to being providing deep-cycling ability, the D31A, D31T or D31M also serve as incredibly powerful starting batteries, with huge initial amperage discharge to spin hard-turning motors.