Product informationVgate Battery At 12V Bluetooth Diagnostic Analyzer Monitor for Android & iOS DeviceVgate battery at is a kind of car battery monitor for all 12V car batteries, works via Bluetooth and mobile phone APP to check the battery status and relative systems in thecars. Vgate Battery AtBle 4.0Battery Monitor Advanced Features: Compatible with all12Vvehicle batteries and installed in the car battery Real-time monitoring via mobile phone app.Check the starting system (cranking) at each engine start and check the starting voltage every hundredths of a second when the engine startsEngine start is automatically detected and check the charging and starting systems (alternator)Receive battery condition notification when you enter bluetooth range and notify mobile phone when some data is abnormalView short circuit and reverse connection protection and voltage and charge information. When the user is close to the vehicle, the app does not need to be openedAutomatically syncs when entering Bluetooth range and data stored in battery monitor for up to 35 days if out of sync.List the time of each trip and check historical data graphically.How to use battery tester:1.Open the car battery cover, find the battery positive and negative. 2.Screw the screw positive and negative, install the product;s red and black connector to the positive and negative pole of the battery accordingly. Then tighten the screw. 3.Pre the app on your phone, it should connect to the device. As it is Bluetooth (4.0), it does not need to pair and connect the automatic battery monitor automatically. 4.Release all permiions while running the app(Battery-At) 5. Check the feature details 6. When a red letter appears on the top left, please pre to reconnect the Ble 4.0. 7. System configuration 8. Notification bar meage