2001 E-350 6.8L V10 Electrical Isolation Questions

[ApacheCheef]

Hi All,


I've done loads of searching, and have filled my brain with so much information about electrical systems - that I feel like I need to lay out a few of my questions and get some feedback. Please take a moment to review a few (hopefully simple) questions...


The van is a 2001 6.8L V10 with the Ford factory "heavy duty auxiliary battery" option; so I've got a starter battery - and a frame-mounted auxiliary battery.


I've procured (4) Lifeline 6v AGM batteries to wire in series/parallel, so I'll ultimately have a sizable 12v AGM bank for "house" power.


I plan to augment the vehicle/alternator charging system with (2) roof-mounted 100w solar panels (and appropriate charge controller).



I plan to keep the alternator charging system simple, by utilizing the stock relay (that's mounted to the underside of the main battery tray).



My questions are:


1) Does anyone know the specs or amperage rating of the relay/solenoid that comes with the factory auxiliary battery system?



2) Will it be able to be re-used in my electrical system, or would it be prudent to upgrade the solenoid?


Thanks in advance for your help!

[carringb]

Factory six batt charge circuit is only 40 amps. And maybe 8 gauge wire. For what you want to do, better off starting over with bigger components.

[ApacheCheef]

Hey carringb, thanks for your response, I appreciate your engagement and willingness to help other forum members.

I’m restarting this project and I’m at wit’s end on the electrical.

Per your recommendation, I will be “starting over” with bigger components. But my question is whether it’s possible to keep the original auxiliary/frame mounted battery tied to SLI battery, yet add-on my (in cabin) house batteries that will be charged via alternator or solar?

Would this require two separate relays? Unfortunately, I only know enough about electrical to be dangerous.

[Scalf77]

If you have a targeted use for auxiliary/frame mounted battery ( winch, off road, lights, etc ) there is really not a reason to keep that battery. I won't help with starting or anything unless you put it to use.

You would need a second relay/solenoid for the house battery bank. Do not attach down stream of the aux relay, as stated before that relay would be limited to 40 amps

If going with a relay to combine the starter battery & alternator I would probably recommend the Blue Sea 7622 ACR. It will give you the most options and also add low voltage disconnect if the alternator can't keep up with the load of 3 battery systems, or for that matter 2.

Choices for managing a house battery via alternator are pretty much covered in this thread Battery Isolators, Separators, Switches & More (updated 2020)

-greg

[ApacheCheef]

Thanks Greg (Scalf77)!

I’m going to remove the existing frame-mounted auxiliary battery and it’s associated components (the relay). I wouldn’t want to connect downstream of that 40A relay, because that’s limiting the charge capacity, correct?

I’d like to maximize the amperage to my house batteries (since it’s ~425Ah AGM bank), but do so “correctly,” so now I’m thinking I want to go the second alternator route - install a second alternator with a multi-stage charge controller wired to my house battery bank (which will also have solar).

Or is that overkill and my existing alternator plus the recommended ACR wired between my starter battery and house batteries will be fine?