Staff Answer
Jun 29, 2026 - 02:24 PM
If you want to monitor all the batteries for volts, amps and amp hours then you need a SmartShunt or BMV 712 for each. If you would be content with just the volts of some of these batteries then each SmartShunt or BMV can read volts, amps and amp hours for one battery and volts only for a second battery. The second battery would need to be close to the first. Another option would be to use the Bluetooth only Smart Battery Sense which reads volts and temperature only.
Getting state of charge from a start battery is not always that successful. To get accurate state of charge measurements the battery need to cycle from time to time. That means being run down at least to 80% state of charge and then charged back to full. This resets the measurement and cancels out the cumulative errors. Start batteries never normally cycle, they stay full all the time, and so after a while all the small errors accumulate and you get a wrong answer for your state of charge.
Getting state of charge from a start battery is not always that successful. To get accurate state of charge measurements the battery need to cycle from time to time. That means being run down at least to 80% state of charge and then charged back to full. This resets the measurement and cancels out the cumulative errors. Start batteries never normally cycle, they stay full all the time, and so after a while all the small errors accumulate and you get a wrong answer for your state of charge.
