Engine battery

[Gerry863]

My battery seems to need a charge about every 5 days or it just won’t start my Jayco Alante RV. This could be a serious problem depending on the area I’m camped out in. If boondocking it would be an inconvenience of the highest order.
I started thinking of the house batteries but am concerned that they might not be powerful enough. I then had the idea that I have an Onan generator I hardly ever use and thought “ of course that is what the designers planned! “ well I was wrong!
What do campers do? Stick out a thumb? My first thought was to equip my Jayco with a spare high cranking power battery and some starter cords! Another thought was to mount it near the generator and run the generator if needed to charge the battery. There must be some technical reason why a button couldn’t be pressed to run the Onan that one could hook the batteries to. Ideas?

[JimD]

I added a little RF relay to the solenoid/relay that connects the house and chassis batteries together while the engine is running. While camping I use a power outlet voltage monitor to keep tabs on the chassis battery. When it drops I simply hit my remote switch while the generator is running and it connects the chassis battery in to be charged. Works like a champ.

I connected my remote relay into the primary side of the rig's solenoid/relay so it energizes it rather than using my small relay to try to carry the heavy charge current.

You must have a lot of static current draw to bring down your chassis battery in only 5 days. Mine does drop but I think it could go twice as long these days. I added my relay back in the day when I had my entire family in the rig. I had set up a multi-tap USB charging block and had it plugged into the rig's power outlet so everyone's electronic device could be easily charged without firing up the generator or running down my house battery.

When I am not using my RV I have a trickle charger on the chassis battery to keep it full. My solar keeps the house batteries up. Happy days!

[mkassab]

The engine alternator, the shore power & generator via the converter do charge both the house and engine batteries.

For the shore and generator power via the converter, the house battery is primary 1 and the engine battery as pri 2 once house is charged.

For the alternator, it also does both engine and house batteries, but may be at the same time.

And, yes, the house batteries will start the engine via toggle switch on the dash and vise versa for the generator.

If your engine battery is draining down that much in 5 days, you need to fix (my opinion) the root cause and not look for Band-Aids. Either something is "ON" or "drawing power" that shouldn't be, your battery is bad or it's not being charged properly.

Mark