BoostBloc6600 ($99) is a surprisingly dense backup battery from Eton. The 6600mAh cell is housed in a plastic block 1.7" tall and wide, and 2.8" deep. At one of the square ends you'll find a Micro-USB port alongside regulatory text; the other contains two full-sized USB ports. The battery can output up to 2.1A when only one device is connected, enough to charge iPad minis and older iPads at full speed. Eton includes the Micro-USB cable to recharge…
