The BMV 712 can monitor everything about your house battery, amps, volts, amp hours, amount consumed, percentage charge and time remaining. It can also monitor the voltage (only) of your start battery. You really dont need all that detail for the start battery, you just need to know if it is charged and if the voltage goes up when the engine is running. Reading the voltage is all you need to do that. So I think the BMV 712 will be ideal for your application.