Question: I am a proud owner of a 1991 Grand Villa it has three batteries, one for the engine and two for the coach. Is it possible to charge the engine battery with the boost switch? If I do not start the RV at least every two weeks the battery go's down.
Yes, you can do that. BUT you are counting on a relay/solenoid working 24/7.
There ARE better ways to do it.
Best:
Use a smart combiner such as Xantrex Echo Charger OR separate smart charger (3-4 amp is adequate).
Acceptable "manual" technique: Use jumper cables from chassis to house battery bank. Can be done at any location where the two are close-- batteries themselves, battery isolator, etc. THE CAUTION: Both ends are HOT with no fuse. You can make a real mess (think arc welding) if either end touches any metal. Never, never leave this connected when the coach is moved.
I just take a 12 gauge wire with an alligator clip on each end and attach to the positive posts. $1.50.
Much better ways than the boost switch. It is non-latching which means it needs juice to actuate and connect the two battery banks. It draws enough power to get too hot to touch in an hour or so.
If on shore power, I have a trickle charger installed at the electrical bus that feeds the engine batteries. The electrical bus in our 1993 U300 is in the wet compartment. Photo shows the trickle charger at the bottom right of the photo. About $20 at HF.
If not connected to shore power for any length of time (a week or more), I run about a 3" wire jumper between the engine and coach battery lugs at the electrical bus. Like Brett says, make sure to remove before the coach is moved. This is probably where Twig recommends.
Without charging, the engine batteries will go flat from various parasitic connections in a few weeks.
Pierce.
I have a similar set up in our 91 GV. My engine battery stays well charged for at least two months. In your case, I would look for a parasitic drain as your situation does not sound normal to me. I cross connect often while on the road, but mainly to charge house batteries. I dont see any reason not to cross connect while plugged in to maintain the engine battery if needed. What am I missing?? Thanks and have a great day ---- Fritz
Thank you all for the great advice. Did not know I would be over working a relay so that was some good information. So much to learn, but we love this 91 GV. I must say all but one post was very helpful except for one. I am not sure why you bothered. Safe travel to all! 8)
Mustang, Glad you found a solution. Please don't judge us all by the comments of one person. It takes all kinds and we try very hard on the forum to tolerate even those who sometimes are hard to like.
Gary B