This is a rechargeable lithium ion cylindrical 18650 battery with a JST-PHR-2P connector. The connector is "reverse wired", meaning that battery + & - are connected to pin 1 (+ = red wire) & pin 2 (- = black wire), respectively. The integrated PCB protects against: 1. applying too much voltage when charging, 2. demanding too much current when discharging, for example, if the output is a short circuit, and 3. deep discharge - the load is disconnected once the battery voltage reaches 3.0 V to prevent damage.

We use lithium ion batteries in our own products, in sufficient volume to procure directly from the factory, so we can pass on our cost savings to people who need smaller quantities.

We have used PKCell batteries in our own products for several years because of their high-quality construction and reliability.