House/chassis battery issue

ramsaymike wrote:
I have a 2007 Coachmen Concord DS275 and discovered that the only way to charge the chassis batteries is by the alternator. Shore power charges house batteries only. This is a real issue for me as the engine cracking speed is critical in starting the 6L Ford diesel. I also have a solar system but it too is house only. I would like to be able to use the solar charging as needed to keep the chassis batteries fully charged. The battery interconnect solenoid would seem to be what I need to use but when I activate it (apply 12v) the headlights turn on which greatly reduces the charging efficiency. Any ideas appreciated.

IMO, what you are experiencing is completely normal and it is how most Class A/B/C gas MH's are wired from the factory. The chassis manufacturer (Ford/Chevrolet/Mercedes/etc.) designs/builds the chassis including the charging system which NORMALLY charges the engine (chassis) battery. The coach battery(s) are charged by the MH builders system. (It is often interlocked to the chassis batteries when the engine is running) For my Class A gasser, the easiest way to charge the chassis battery is to use a separate automotive type 12 volt charger (I use a 10 amp charger) which is plugged into a 120 volt outlet inside the MH. You must run the generator or be plugged into shore power to do this. IMO this is the easiest/safest/cheapest way to charge the chassis battery without causing other issues. You can manually hold down the house/chassis battery interconnect switch, but that is NOT what it is designed to do. IMO, charging deep cycle and automotive batteries together with the same charger is not a good idea and can result in failing to get all the batteries fully charged or cause some to be overcharged. The house/chassis batteries are often of different age/chemistry/voltage and don't like co-operating with each other when charging.

You could also use a separate charger connected to a 12/120 volt inverter which is powered by your solar system.

Chum lee