The Phantom 2 sort of gives you only 1 choice: the charger built in to the battery. The part that plugs in to the wall (or your car) is just a regular 12.6V DC supply. The circuit board in the battery then takes this and balance-charges the 3 logical battery cells (which are really 2 physical cells in parallel each). You can use wall chargers that supply more or less current (up to a limit). You can get adapters to charge more than 1 battery at a time. Some of them can provide a voltage reading. That's all I'm aware of.