Charger Circuit Boards are from Project X. With slight modifications, they can be made to work with NiMh battery packs (although not recommended and not for extended periods of time). This unit has 5 circuits for Lead Acid Batteries (6 and 12 volts), and 5 circuits for NiMh battery packs (6 and 7.2 volts). The charging voltage is displayed on a Digital Panel Meter (a very bright LED DPM). An 11th jack is provided to measure external voltages.