No need any Batteries or Charger, gets the power directly from the OBDII Data Link Connector in your vehicle. It’s equipped with a 2. 5 feet long cable and made of a very thick flexible insulator. There are 4 buttons on AD310. The Up and Down button for scrolling the menu, the Enter and Exit button allow for navigation back and entering menu.
https://www.amazon.com/ANCEL-AD310-Enhanced-Universal-Diagnostic/dp/B01G5EA74I

