charging house batteries from the alternator

In my recently purchased 2002 Winnebago Adventurer, I see that they no longer offer the option to charge the house batteries while driving down the road. Apparently,the house batteries can only be charged from shore power or running the generator.

There is a "battery boost " switch which allows the house batteries to start the engine. My question is: if I leave this switch in the battery boost position while I'm driving, will the alternator charge the engine batteries plus the two house batteries???
charging house batteries from the alternator

You have the right idea but it won't work exactly like that because the start boost switch is probably a solinod. To check this out, with the ignition key in the on position and everything quiet (engine shutdown), push the boost button and you should hear an audible click. If so the boost switch is a solinoid as I mentioned.

You can do exactly what you are saying by purchasing a lighted switch rated for 15 to 20 amps and running a 10 gage wire from the positive side of the engine battery through the switch, then to the positive side of the house batteries.

But here is the catch, the reason for the lighted switch is to remind you to turn it off before you shutdown the engine. Never turn it on while the engine is shutdown lest you drain the engine battery down then you will be looking for a jump off. Never try to start the engine with the switch in the on position because you will probably smoke it.

More than likely there is somewhere you can purchase an automatic switching system. At a boating shop because I had a switching setup in my trawl boat and I know a lot of sport fisherman have something in the more expensive bass boats.

Hope I was of some help. :laugh:
charging house batteries from the alternator

Thanks for the input Poppa,
I had a 1985 Winnebago and that had the switch right on the dash. If the switch was "on" then the alternator would charge the engine plus the house batteries. The warning there was, that if the switch was on, and I started the aux generator I could backfeed the engine's alternator and blow it out. Needless to say, I was pretty careful with the switch. A couple of times I forgot about it, nothing bad happened but I was probably lucky.

They probably discontinued using this switching arrangement on newer units as too many problems can and did occur.

I am familar with the marine type battery switches but never thought about instaling one in the RV. What you say makes sense - if I don't forget the switch. (remembering things like that get harder and harder each year ).

Your comments were very useful and I think I should leave well enough alone and run the darn generator while Im traveling down the road if I need to charge the house batteries. The more I think about crossing over the shorepower, generator and alternator I see that I could be asking for pretty big trouble.

Thanks for setting me straight.

Little Paulie
charging house batteries from the alternator

Well I had a little time. There is a battery switch that may do the trick for you without a bunch of extra wiring. Contact the following,, They make an adapter that connects to the back of your altenator on the battery connection. You then connect the existing witre to one post and run a single wire to the house battery posiitive terminal. Check with them to make sure that is how the tbattery disconnect works they sell. :clown:
charging house batteries from the alternator

Thanks Poppa for the tip. Will investigate it and see what they say.

I checked the RV carefully today and the switch for the battery boost is as you predicted. As soon as you take your finger off the switch, it automatically clicks off and breaks the connection between the house and engine battery.

Thanks again.
Little Paulie
charging house batteries from the alternator

It can't possibly take more than 15 minutes to recharge your house batteries from your generator. Why risk electrical problems by "rigging" a wire and switch from your alternator to your house batteries just to save running your generator for 15 minutes?

There are numerous isolators that can be wired in (my 2005 Winnie has one) to recharge your house batteries, but for such a small savings why mess with it?

Is there some other reason?
charging house batteries from the alternator

Are you sure that the alternator is no longer designed by Winnie to charge the house batteries? Charging off of generator takes far more time than from the alternator. Dont understand why Winnebago would eliminate this feature. Have you talked to Winnebago Customer Service about this? :question:


Senior Member
charging house batteries from the alternator

quote: see that they no longer offer the option to charge the house batteries while driving down the road.

I would bet you that your system is designed to charge the coach batteries from the chassis alternator when traveling. If it is not doing so now, there is some problem, probably with the battery isolator. It is intended to close once the chassis engine has started to charge the coach batteries as you travel.

Also, if you choose to charge the coach batteries from your genset, it will take a lot more than 15 minutes to do so. The best way to do that would be to get a good battery charger and connect it to the AC power from your genset and charge them in that way. Your genset only puts out 120V-AC power so all that is there to charge the coach batteries from the genset is your converter, which is very slow.
charging house batteries from the alternator

This is a question I've had for a long time.

I want to charge the batteries with an external battery charger. I plug it into a 100V outlet and run the generator. Not knowing what the circuit looked like I would charge one battery at a time (the house has 2 batteries). It is a pain, but, was afraid I'd blow somthing in the generator/converter/inverter if I hooked up to batteries that were already hooked up to the generator.

So from what you describe, I can just hook up the external battery charger, connect the clamps to the house batteries and go.