High quality 3.7 V Li-Ion rechargeable battery pack,Made of 2* 2200mAh cylindrical 18650 cells with PCB and poly switch for full ... 1. High quality 3.7 V Li-Ion rechargeable battery pack2. Made of 2* 2200mAh cylindrical 18650 cells with PCB and poly switch ... and prolongs battery life7. Perfect 3.7V battery pack for bike lighting, RC toy, robots, laptop and DVD external battery Li-Ion 18650 Pack 3 ...