Chassis Batteries Dead

[Dennis Belfils]

OK, so we have been parked for a couple of months now with full hook-ups, and the Chassis batteries went dead. I realize there are parasitic loads to them, but in the past we would start up the engine once every 30-45 days. That being a bad idea, we stopped the practice. I was under the impression our 100 watt solar panel coupled with a Heliotrope RV-45D controller would alter charging between the House and Chassis, giving priority to the House. Upon checking the controller, the Engine terminal has no output wires attached to it.
My question is, should I run a new wire to the Chassis Batteries and the best way to accomplish it? Or run the generator once a month for 15-20 minutes? Or something else? Pretty sure the 6+yr old Chassis batteries need to be replaced, but don't want them to die. We plan to be parked here for an indeterminate period of time. Any input would be appreciated.  Thanx

[Fred Brooks]

     Dennis,
Here is a brief overview how the coach and chassis batteries are charged from shore or generator power. Your coach has a B.I.R.D. system (bi-directional relay delay). When the system senses that the inverter/charger has 120 volts present and the battery charger starts to charge the house batteries, when the battery voltage exceeds 13.1 volts the Bird delay relay activates the Big Boy solenoid and then starts to charge the chassis batteries. My suggestion is read up on the system and then trouble-shoot your issue. When you go to log in the forum, go farther down and click on "coach assist".
Scroll down until you find "battery and charging systems" Click on the first 3 articles about Bird delays and relays and how it works. My suggestion is to replace the chassis batteries to remove that issue from the situation. Hope this helps, Fred

[Steve Huber Co-Admin]

Dennis,
Access Coach Assist by logging on to the BAC Club website. It is under the Technical tab.
Steve

[Joel Ashley]

Dennis, how did you rate the 45D when others of us Monty’s got 30D’s?  🤔😁

As your Coach Assist research and thread search’s here may reveal, its a common malady that the Big Boy contacts corrode/freeze up.  Some owners have dismantled, cleaned, and repatriated theirs, or done that to their old one to keep as a spare after installing a new Big Boy.  I’d bet there are even YouTube videos about that. 

Less common are BIRD failures, except for the rare loose wire situation.  So after reading Steve’s advised documents in Coach Assist, check all connections there, or that a wire from it didn’t get pinched in the door like I have to watch out for with mine. 

As Fred commented about, once the house set are at a certain voltage, the BIRD reverts park or genset charge current to the chassis set, although my understanding and experience is that it’s at 13.4 volts.  I think that will happen via the BIRD even if you’re relying only on solar.

Joel

[Dennis Belfils]

Thanx for the responses. Have reviewed the info, and it gives me a direction to troubleshoot. Not sure if I'm up to getting into it that deep, but will check all that I can.............