Sizing a House Battery Bank?

Question:

We purchased a new motorhome last summer and I was having some trouble with keeping the house batteries charged. I am not sure if the charger I have is the best one for the job. There are 4 US 2200 XC Batteries that are charged by a Magnum ME 2012 Inverter/Charger. There is a remote (like the one you put on our boat) but it does not have SOC info and I do not know why my batteries die so fast. What accessory do I need to install to have proper SOC readings? There are two systems (a 110V and a 24V), five televisions, water pump, fans, lights, residential fridge, and a few others that all seem to run off of the battery bank when not connected to shore power. If I’m a betting man the draw from the fridge alone will kill those batteries in a matter of a couple of hours. It has a built in Onan Generator that I use to charge the battery bank, but I have to run it all the time. I do not know if my batteries were damaged from misuse when on the dealerships lot.

Answer:

The four golf cart batteries make for an OK at best battery bank. The Magnum ME 2012 charger has a 100 amp charging capacity and remote has the ability to become a battery monitor. It is called the battery monitor kit and retails for about $200. That way you will get a SOC for your batteries.

All of this load adds up to a huge amount of power but the fridge could probably last a day on those batteries, possibly even more. This battery bank is too small for this motorhome. I would consider getting a larger bank, perhaps 4 X L16 if you can accommodate the height. Also, you should consider the EFOY generator for quiet power. See our Tech Talk article about it: http://www.pysystems.ca/tech-talk/techtalk/2014/12/03/efoy-fuel-cells/