Battery issue

My coach will charge the house battery from the engine, but shore power won't charge the chassis battery. Found that out when we went on our first week-long trip a couple years ago. I usually run the dash radio (powered from the chassis battery) all day to keep our dog's hearing entertained (otherwise known as keeping him from hearing everything in the campground and barking at it until we get evicted) when we're not with him. Although the radio kept playing all week, the engine wouldn't turn over when we got ready to leave...had to use the boost feature...glad I had that! To remedy that situation, I installed a Battery Tender trickle charger that is connected to the chassis battery and works when plugged in to shore power or on generator. The Battery Tender itself is plugged into the old TV outlet in the dash that is defeated when the engine is running, so the Tender is not trying to charge in addition to the alternator. Been working great for 2 years now!

Thank you Sailor Lou!! That's the perfect remedy for my problem. Thanks everyone. I don't know why the coach is designed that way but this should address it.

Thanks very much. Starting to make sense. After all these years, this is the first time I’ve been hooked to 50 amp for extended periods. The coach has a disconnect on the coach battery most likely for that reason. It’s fully charged so I’ll disconnect that 1 battery and try that. This coach has just 2 very large deep cycle batteries. Never had the issue when stored because from what you guys have said, that’s when solar charges one which keeps the other charged. Thanks again

Starting batts are not charging...several systems used over the years by Beaver and Safari. The easiest, least expensive solution is to install one of these

http://www.lslproducts.net/TLSPage.html

After one week, your chassis battery should still have held it's charge unless you had something that was left on and drawing power. I would use a meter to check how much current is being drained from the chassis battery when it is parked. Then you can pull out one fuse at a time to see which circuit is drawing current and discharging the battery.

Modern coaches come in two flavors. Older only one, for this post

My Coach has something called a Bi-Directional Isolator Relay.
That means that as I sit here plugged into 50 amps the chassis battery is charged by the HOUSE.. When I unplug in a bit the two systems are independent, but when I crank up the engine the Engine (Chassis system) will charge the house.

OLDER (And still some today) do not have this they have a uni-directional isolator.. Engine charges house. but not the other way around.

Multiple solutions.
Short term .. Turn off ENGINE (Chassis/main) Disconnect, leave AUX connected, when camping.

Better;;;; Trick-L-Start. Easy 3 wire hook up.. adds the "Reverse" to the isolator.

NOTE: Starting batteries really do not like being discharged more than 10-20 percent.. they can need replacement when they get too low just one time.

House batteries, if MARINE/deep cycle.. may survive one "DEEP!!!" discharge (Below 50%) but don't make book on it.

DEEP CYCLE (IE: GC-2) have no problem with 50% state of charge and often recover from even deeper discharges though overall age will be lost

I did OH S!!! discharges about 4 or 5 times on my original batteries. they lasted 9 years Only done it once with the current set, when the converter died.

Sounds like you have one of these.
Heart manual

I have a Heart 2000 Invertor. Says its in charging mode but the green light is not on. You could be right. It could be failing.

You should have either a converter or an inverter/charger. Either of these units should charge the batteries. They may or may not charge the chassis batteries.
I would guess by year you have a converter. It could be failing and you are running off battery power.
Look around the 120 volt AC circuit breakers for a converter. It maybe located outside near where the shore power connects to the rig.