RV Clinic: Battery Upgrades
We purchased a new Cougar fifth-wheel trailer last summer. The trailer came with one standard 12-volt battery to run the DC side of the system. Since we tend to do a lot of dry camping, we are always looking at ways to increase the battery capacity and extend usage without killing the battery, and were thinking of adding additional batteries. Would it be better to add a couple of 6-volt golf-cart type batteries wired in series to provide 12 volts, or possibly a couple of 12-volt batteries parallel wired, providing the 12 volts? Which is a better way to go. I am in the process of installing a solar system that will charge the batteries with an output of 175 watts. I also intend to add an inverter in the future and integrate that into the overall system.
– Bob Kelley | Grand Junction, Colo.
Before you upgrade the battery system in your trailer you should first figure out how much power you will need to draw from that new bank of batteries. Websites like www.lifelinebatteries.com/rvsizing.php include calculators that allow you to estimate the power consumption and battery sizes you will need. Generally one 12-volt battery is good only for light-duty use. Most moderate users who dry camp find a pair of 6-volt golf cart batteries sufficient. You can pair most batteries, 12-volt too, in parallel as long as they are the same age and same strength. It’s only when one battery is significantly weaker than the other that we don’t recommend it because the weaker battery may cannibalize power from the stronger one in parallel.
– Ken Freund