spotrot wrote:
It's interesting to learn of the difference in systems RV's have.
I posted this because I guessed that many others have a coach wired like mine, it being a 2008 Itasca 30B. Some of the above was surprising to me and not noted in the manuals.
As I mentioned, the engine's alternator does not charge the coach batteries.
And I have installed a simple switch to link the batteries together when I want for charging on the road or when plugged in.
spotrot,
You seem pretty sure yourself when doing all your checks. That's great. And at present, you're pretty dead sure your coach was set up to not charge the house batteries with the engines alternator, correct? Well, at this point, you may have determined that your engine is not charging the house batteries but, that doesn't mean it's supposed to be that way. As just about every answer to your original post has indicated, your alternator SHOULD charge both sets of batteries.
Just how it does it or, is linked or wired up to do so, all depends on just how the coach builder set it up in the first place. There are a few types of dual battery charging systems utilized by coach builders. But, I'd just about bet my house that, a 2008 coach, no matter who built it, engine type, chassis type etc. is set up for the engine alternator to charge both sets of batteries. I could be wrong but, I doubt it.
I have no idea what kind of dual battery system you have. I'll give you a short story. Our coach, an '04 Itasca Horizon 36GD with the C-7 330HP CAT, has what's called the "Battery Boost" switch on the left side of the dash. The switch itself, is wired to a extra heavy duty solenoid. The function of that solenoid is dual purpose:
1. IF and when the chassis batteries are low in charge or, just don't have enough to turn over that CAT, then a push of that switch, will link the house batteries into the starting circuit and allow the extra power from them to help start the engine.
2. After the engine starts, that solenoid is wired in such a way that it closes and, that's what links the alternator to charge the house batteries.
That particular system, is used on many, many type/make and model coaches. As stated, there are other types that link the house and chassis batteries for alternator charging.
As for dual banks of battery charging with shore power, well, that too has various setups to accomplish this. For instance, our coach, the one mentioned above, from the factory, DID NOT ACCOMODATE the ability for shore power or, generator power, to charge both battery banks. I later remedied that with what's called the "Amp-L-Start". That little tiny black box, is a "thinker". It's actually tied into that solenoid I was describing above. And, it's tied into the chassis batteries too.
When it sees a .5V difference between the house and chassis batteries, it steps into action and, provides a maximum of 15 amps to be diverted to the chassis batteries for charging. The Winnebago factory started installing the "Trik-L-Start" (Amp-L-Starts) little brother, in or around early '06.
So, that's how some of the make/model/year coaches link charging of both systems, at or during either engine running or, shore power.
So, in my opinion, while you may have determined that your alternator is not charging your house batteries, I'd also bet something is broken or, malfunctioning which is causing that situation. Sorry for the long dissertation but, I thought it better to lay down some history for my explanation and, that might help you in determining that something is wrong with your system and maybe where to look for the problem. Hope this helps some.
Scott
