The BM-2 is designed to monitor performance of 12 volt lead acid battery systems with capacities of up to 999 Amp hours. It is supplied complete with a precision 200 AMP shunt and a prefabricated cable assembly to enable simple DIY installation. The unit continuously monitors voltage, current (charge or discharge), number of amp/hours (charge or discharge), the batteries state of charge and the time to charge or discharge. This information leads to more efficient use of the battery, which can enhance battery life and reduce the risk of failure.