[12V and 24V Automotive Battery Tester]:AUTDER AD-808 automotive battery tester is suitable for all 12V and 24V automotive batteries of cars, sedans, motorcycles, trucks, mobile homes, crossovers, SUVs, boats,yachts, lawn mowers and even golf carts.Voltmeters for automotive batteries are accurate to close to 0.01 V, for example B. 12.29 V.[GENERATOR CHARGING SYSTEM ANALYZER]: In addition to providing a quick reading to see if a car battery needs cracking or replacing, it also tests the condition of the generator output to prevent damage to thebattery due to overcharging or incomplete charging.[Ease of Use]: We creatively developed three speeds for testing alternators, 12V batteries and 24V batteries. If you hold the runner in the center position, the LCD displays the voltage in timecurrent and the LEDs indicate the status of the alternator.When switching to 12 or 24 V, the LCD displays real-time voltage and LEDs indicate battery status.[Reverse connection and overvoltage protection]: In the event of a reverse connection, the error code "ERR" is displayed on the LCD screen and the built-in buzzer sounds.Digital voltage is tested between 4 and 20 VDC.If the voltage is out of range, the display will show “LO” (< 4 V) or “HI” (> 30 V).Each package includes the AD-808 battery tester, alligator clips, cigarette lighter adapter and user manual.