TrustFire TR10440 600mAh 3.7V Rechargeable Lithium Battery-BLue(4-battery pack) TrustFire TR10440 600mAh 3.7V Rechargeable Lithium Battery-BLue(4-battery pack) This product is TrustFire TR10440 li-ion battery with great capacity and without memory effect. Compared with other on-off battery, it can recharge for many times and is contribute to protect enviroment. The voltage of full charge and cut-off discharge is 4.2V and 2.75V.