1. Supports real-time monitoring of 4 vehicles battery . Receives notifications of battery conditions in Bluetooth range. Supports the connection of multiple devices and monitors four devices on the same page. 2. Automatic cranking system automatically while engine is starting. 3. Automatic charging system (alternator) test 4. Real-time battery health monitor . Real-time display of battery power, temperature and voltage. 5. Alerts mobile phone if detects abnormal data. Abnormal voltage APP automatically sends alarm notification abnormal. Short-circuit and reverse connection protection. Historical device data can be stored for up to 30 days(voltage, charging percentage, and temperature). Save data every 2 minutes.Track, expenses and driving habits are recorded for each trip, which can be exported to Excel files. Automatic synchronization when in Bluetooth range. Compatible with all 12V vehicle batteries. Shows historical data graphically. Engine starting detection automatically. Free app for iOS and Android. Support multi-battery management Exclusive private account, data not be lost Car location seeking function via map. Trip record with map and route. Works with all 12V batteries. /Wireless (Bluetooth 4.2) in10 meter. Lists the time of each driving. Automatically records parking position and provides car finding function through navigation. Color: Material: ABS Package Contents: 1PCS 12V Car Battery Monitor 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.