This PPA includes the battery board with 15 AAA Sanyo 900mAH batteries. It was a very interesting build. It is currently powered with a Steps power supply (see the Steps Gallery) but will eventually have either it's own Steps and/or a beefed up Tread Brick for easy travel).
The battery board is configured to fast charge in about 3 hours and features DeltaV and temperature based backup termination. It is currently providing about 6 hours of run time with the PPA buffers biased to 20ma.