1. Works on 6V 12V 24V batteries, battery ratings from 100 - 2200 ,including and alternator. 2. Reverse connection protection, even positive and negative are inversely connected, you still no need to worry about battery damage. 3. Test result: , SOC, value, rating, voltage,etc. 4. If the clip is not properly clamped,the screen flicker,just re-clamp it. Clip properly clamped screen not flicker. Perfect for beginner Name:Car Battery Tester Know your battery conditions in advance before it dies! Plug and play: button to switch battery type and ok button to confirm. Then input the rated battery capacity. Use BM550 to see whether your car battery is OK. Good:The battery is in good condition, to use. Normal: General state of the battery may continue to use. Poor: The battery is in poor condition, please replace it in time. Perfect for: Cars, SUVs, Pickups, Boats, Motorcycles, Trucks and Golf Carts and more Display state of health, the readable analysis results on 1.8 inch blacklit screen High precision amplifier and calibrated by professional instruments give you the reliable results in seconds! Over-voltage, short circuit and spark proof protection. Don't need to worry about battery and equipment damage Support both in-vehicle and out-of-vehicle tests, no need to remove the battery from the vehicle. provide you with more accurate test results quickly, thus replacing the bad cell in time. 1. Identify battery status Good or Replace 2. Check Battery Capacity - Cold Cranking Amps (), BCI, CA, , , DIN, IEC, EN, SAE, GB information relative to battery rating. 3. Check Internal resistance value (Ohm) 4. Display battery life in percentage (%) Colour:As Shown Material:ABS Package Contents: 1 * Car Battery Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.