Go to Amazon Sites : http://www.amazon.com/gp/product/B0043G1FZG?tag=shitmycatsrea-20 <br /> <br />BatteryMole Car Battery Warning System (12 Volt Automobile Battery Monitor with Battery Failure <br /> <br />Patented technology that virtually eliminates unexpected car battery failures <br />After the engine is off for a minimum of 4 hours engine start times all cars start voltages most cars are sampled and displayed <br />Calculates the batterys state of charge after the battery has been at rest for 4 hours <br />Performs a comparative analysis of engine start times and start voltages in order to determine the batterys health <br />Warns of low battery voltage charge alternator charging problems relatively slow engine start times and relatively weak start voltages
