Community Forums

Lonnie & Bona · 05-29-2023, 08:22 PM

I am in the process of switching my house batteries over to Lithium. My 2001 Spartan Chassis is set up on the BIRD system. I want to disable my coach batteries (Lithium) from being charged by the alternator. Between the chassis solenoid, coach solenoid, and the Bi-directional isolator relay, I am not sure which wire(s) needs to be detached from which device so my house batteries will no longer be charged by the alternator. Please see the attached photo of my system which is located in the electrical bay of my Mountain Aire. There are wires ran from the ground, coach battery, ignition, relay terminal of the Bi-directional isolator, but no wire from the genset terminal. The coach solenoid is in the upper left of the photo, the chassis is in the upper right of the photo, and the Bi-directional is in the lower left of the photo. Can someone please tell me which wire(s) need to be disconnected to disable the alternator of charging my Lithium batteries? I would also like to know if it is also possible to disable my system so the chassis batteries will no longer be charged by shore/generator power? I would like to keep my system as simple as possible. K.I.S.S. For additional info, my converter/inverter is an older 2500 Xantrex/Trace model. Thanks for any help anyone can give me concerning this.

2004Horizon · 05-29-2023, 09:29 PM

I can see your BIRD black box -- visible in your picture -- so just follow the wires to the solenoid and disconnect them.

Skip426 · 05-29-2023, 09:44 PM

Yes if you want to disable both the , coach battery charge from alternator and the chassis battery from the inverter /charger ; then disconnecting the solenoid from the control box works BUT you'll also loose " Boost " function.

You would have to take the " Boost "wire from the dash that is currently attached to the control box and hook it directly to the solenoid , so the solenoid is only active with the boost button pushed.

153stars · 05-30-2023, 07:35 AM

I agree and was going to suggested same thing. LIFEPO are not crank batts but can help recharge chassis batts and give at least 100a per 100 ah. A DC-DC charger is usually added to charge house batts while driving.

Quote:

Originally Posted by Skip426

Yes if you want to disable both the , coach battery charge from alternator and the chassis battery from the inverter /charger ; then disconnecting the solenoid from the control box works BUT you'll also loose " Boost " function.

You would have to take the " Boost "wire from the dash that is currently attached to the control box and hook it directly to the solenoid , so the solenoid is only active with the boost button pushed.

twinboat · 05-30-2023, 09:27 AM

Simply unplug the red wire from the BIRD, marked relay. Done.

Solenoid can't close with no signal from BIRD.

shootist · 05-30-2023, 09:41 AM

I originally put a switch in my rear run box to disable the bird/big boy relay because it hummed too loud in the bedroom. The second time I had to clean the contacts in the big boy I put in a blue seas ml-acr. You can just bolt it in, hook up the battery cables and leave it at that. Turn it to locked out. If you ever needed boost you would manually turn it to combined. Or you could wire it to the dash and make it fully functional from the dash.