The Antigravity Battery Tracker monitors your vehicle battery status through your phone or tablet by using our free Battery Tracker App (iOS or Android, Bluetooth 4.0). The app has three main pages: Voltage Test, Cranking Test and Charging Test. The simple interface makes it easy to monitor the battery's voltage, automatically check its performance during starting, and test your alternator's charging operation. You can view real-time data as well as historical results (31 days) that graphically displays the dates, voltages and more. The tracker will even send a warning to your phone if your battery is getting low and needs a charge. You can choose the alerts and notifications you want to receive.