This Li-ion Battery Holder is specifically designed for the micro:bit educational robot Maqueen. It can be used to hold a CR123A 3.6V lithium rechargeable battery to provide more than 8 hours of continuous power for the Maqueen. Using this environmentally friendly product, you can save about 200 batteries per year! This Li-ion Battery Holder integrates charging circuits and a Micro USB interface, so you won't need to buy another charger. It also includes over-current and reverse-connection protection for it to improve the safety in using Li-ion Battery.