Hi,Generally, it is designed for 18650 batteries, with a flat head and no protection circuit. If used with lithium batteries, you can choose one with a protection circuit.

Note:If using a lithium battery, the required voltage is 3.7V;

if using a battery pack, please make sure it is a parallel battery pack.

There are 2 XH2.54-2P battery connectors on board, it is recommended to use the same type of battery.