Patented (US 8,386,199) BatteryMole Car Battery Warning System.
This freely available application displays the car battery's voltage, temperature, state-of-charge, engine start voltage and start times as transmitted by the 4 Peaks Technology LLC BatteryMole Montior (Bluetooth):
http://www.amazon.com/BatteryMole-Monitor-Bluetooth-Detection-Technology/dp/B01C0S0WZC?ie=UTF8&keywords=batterymole&qid=1461004948&ref_=sr_1_1&sr=8-1
The BatteryMole's patented technology analyzes your vehicle's battery and starting system like no other product. Simply clip the unit onto your battery. No tools are required. Install this free Android application and you are done. Not even a $4,500,000 Lamborghini Veneno roadster is capable of telling the driver it is time to replace the starter battery
~ Patented technology (US 8,386,199) that virtually eliminates unexpected car battery failures
~ Captures engine start times and start voltages
~ Calculates the battery's State of Charge
~ Generates alarms when battery nears end-of-life or is in a low State of Charge condition
~ Monitors the alternator and battery voltage for alarm conditions