2/3/4S 3-6V to 8.4/12.6/16.8V Li-ion Battery Charger Step-Up Boost Module
£3.11
4S 16.8V version LED indicator: "CR" LED is charging status indicator. li-on lithium battery 18650. Input current: 1A (1A version); 2A (2A version); 4A (4A version). Good adaptability to input power with limited drive capability.
