Quantity   Component name
1 × Stock UV3R charger base.
1 × Mini USB 5V 1A Lithium Battery Charging Board The can be found on ebay. Search for "USB Lithium Battery Charging Board" will return a number of board options. Note some come with mini USB and some come with micro USB connections. get the one that suits your needs.
1 × 20gugae wire Red and black wire makes it easy to identify the polarity, but any wire will work.