TrustFire TR18650 2500mAh 3.7V Rechargeable Lithium Battery-BLue(2-battery pack) TrustFire TR18650 2500mAh 3.7V Rechargeable Lithium Battery-BLue(2-battery pack) This product is TrustFire TR18650 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.