Battery monitor for vehicles - 12V voltage tester with low charge alert1、Features: Receive notification of battery conditions when enter BLE range, check starting system and charging system, list the time of each driving, review voltage history in graph mode. 2、Function: Check battery state on phone APP via Bluetooth 4.0 when device is installed, supports for iOS and for Android users, which has high efficiency and accuracy. 3、Easy Operation: The battery monitor can connect with battery directly, with no code required, compatible with all 12V vehicle batteries, with 6‑20V voltage. 4、Practical: Ensure safe operation with short circuit and reverse connection protection, and it's ultra low power consumption, with average current of 1.0 mA. 5、Alert: Alert mobile phone if some data abnormal, and has the function of low battery, viewing charge history, and displaying the charging status of the battery.