Test 12v batteries capacity, crank amps, cold start without a multi-meter. This is a cool tool to have in your toolbox for testing batteries. Check out its functions in this quick demo review. https://shopping.wed2c.com/s/1gELjjw0-00
https://www.ebay.com/itm/Konnwei-Kw208-Car-Battery-Battery-Resistance-Tester-/235088958329