Battery GP Crane stock 10.8V/3700mAh is made of NiMH cells GP. It's a special high-capacity battery for high discharging currents. Quick charge: 65 minutes/3.6A, Imax: 30A continuous/58A peak, Ri = 0.002-4ohm. The battery is designed for use in weapons with a very strong spring. You can also use it in guns Systema PTW M4A1 and M16A3 with a set M150!