The rechargeable battery for Swift RL Petzl headlamp is Lithium Ion and recharges via a micro USB port. The battery also has a light charge indicator that allows you to evaluate at any time how much charge you have left. With Accu Swift RL you get high performance even at low temperatures. The upload takes place in six hours. Instructions. Petzl Accu Swift RL rechargeable battery for Swift RL headlamp