NuPower 55.5 Watt-Hour PowerBook Battery

Newer Technology's NuPower AL15 55.5 Watt-Hour Battery ($140). The high-capacity replacement battery offers more capacity and longer run times than the stock Apple battery, letting us surf from the couch for much longer than we could before. Plus, the NuPower battery not only runs longer than the stock one, it will also last longer by providing more use cycles
before a new one is needed.