I've figured out more about how the power and charging circuits are going to work. After hours of Googling, I've determined that I don't particularly like any of the charging options. What I would really like is the ability to charge with a micro USB cable, but that obviously won't work unless I break the batteries into eight 1-cell packs and charge them in parallel. This is feasible, but I already ordered the 2-cell packs, so I'm going to build with that for now. I'll draw up schematics for both designs, though. In the 2-cell pack design, there will be a power bus and a charge bus, with all the batteries independently switchable, mostly because that will look cool. The power bus will also have a micro USB port on it for powering from the wall. The last thing I'll include in the power circuit is a USB port for charging your phone from the internal batteries, with a 2 A current limiting circuit. Maybe I'll make that switchable, because the more the cooler looking, right?