V8 Dual Batt Set up. Tell me what I'm doing wrong... (1 Viewer)

[Taylorious]

Here’s my full breakdown on the system, with clarification where I think necessary:

IMPORTANT EDITS to Post #1’s wiring diagram:

1. The 1st adjustment is the wiring of the switch, which has both post #3 and #8 connected to the house battery in a 2A circuit.
2. The 2nd is the “hot” 8awg line to the rear of the vehicle has been protected with a 100a Bussman circuit breaker as opposed to a 100a fuse, and is running a full 8awg return ground.
3. The two voltmeters are both fused (5a) and switched to their respective battery of indication.
4. There’s a 20a Renogy “Voyager” solar charge controller for optimizing the system when engine is off for 24+hrs now installed and working as well (paired to 100w panel).

Breakdown:

Would I do this again?
100000000% yes. This was/is, besides the differential locker, the most useful modification I’ve made to the Cruiser.

The switchable voltmeters and (most importantly) ACR is the heart of the system, and as previously mentioned, really the treat. I can isolate the “House” and “Start” batteries if I wanted at any time manually from my cabin, I can combine them with “Smart” isolation that will automatically isolate them when there’s a voltage imbalance, or I can “Hard” combine them to do something like charge while driving or winch.

Further, flicking on the A-pillar switches and seeing the little voltmeters jump up to 11-12-13-14v is wonderfully reassuring. And, I can flick JUST the “House” meter on when the truck’s sitting in camp to see how much voltage my solar is sucking in… real slick, sez I.

It’s been used 95% of the time to keep a Norcold NRF45 electric refrigerator running constantly (Set 28’f/37’f) and it has never dropped ‘house’ battery voltage below 12.5v. Granted, this cooler has a built in selectable shut-off/turn-on for voltage limits, but… even before last week’s Solar supplement, this has been used to great effect.

The other usages have been mostly small air compressors to fill things like showers and lake floaties. Nothing like a 35” tire, but… I have NO doubt that it’d easily top those if I wanted without using much power.


Adjustments/Modifications/Pitfalls/Thoughts for anyone seeking to do this themselves:

1. This is a good time to upgrade the “Big Three” electrical cables in the engine bay. (Battery to Ground, Alternator to Battery, Battery to Solenoid/Starter)

1. If you can fabricate well, you can do with a cheaper / different battery box than the 4Plus. That said; it’s a BEEFY boi. I’d not hesitate to use it again, since I know it won’t break. NOTE: It does NOT fit the ACR in stock configuration, so plan on making a bracket.

1. Plan on taking out (at least) 1/2 of your interior, and 100% of your dashboard. I did Dynamat/Noico, New Carpet, and New Door Cards (Thanks @DrLui ) at this time… and it REALLY made life easier. This really was the key to ease, since I had everything able to be routed where I wanted and could re-assemble as I needed. It’d be possible, but difficult, without this.

1. Mounting the rear fuse box required me to fabricate a custom inner quarter panel bracket. It sits just aft of the rear seat upright locks. Without the 2 12v plugs, you’d never know it’s there… but I couldn’t think of how else you’d build this custom hanger without a welder.

1. EVERY electrical connection from 10awg on down is soldered. I don’t believe in crimps and splices, as they’re another failure point, and I DON’T want to take the dashboard apart again unless I have to. I really, strongly, whole-heartedly recommend this.

1. I have nothing against National Luna, or any of the Out-of-the-box other systems out there… but dollars-to-donuts, I knew I could build a better system using Blue Sea Systems components and using my own garage time. I’d really recommend this if you’re considering just buying a ‘kit’, as it’ll educate you as well as give you something to be proud of making yourself.

1. Perhaps the most significant: I wanted 99% of the system (sans REAR fusebox/ports) built into the engine bay. As such, I welded up a custom tray to hold the 2 fuses, the ACR, and the solar charge controller. This needed real estate meant that I had to move, re-bracket, adjust, and extend the following:
   1. The ECU and wiring harness and associated OBDII wiring.
   2. The ARB compressor and associated fuses/wiring.
   3. The Charcoal Canister

Full Parts List:

• x2 Optima Yellow Top AGM 34/78 series Batteries.
• Trail Gear Optima Battery Box (Start)
• 4Plus parts battery tray (House)
• Blue Sea Systems 7622 ACR w/ Switch
• X2 Blue Sea Systems 200a fuses and holders
• Bussman 100a Circuit Breaker
• Blue Sea Systems 6-circuit Fuse Box
• Blue Sea Systems 2-port 12v Power Outlets
• gaugepods.com FJ60 3 A-Pillar pod
• X2 VDO Gauge voltmeters
• X2 LED illuminated rocker switches
• Renogy 100w Folding solar panel
• Renogy 20a Waterproof Voyager Charge controller
• 2/0awg wiring + terminals to suit
• 8awg wiring + terminals to suit
• 12awg wiring + terminals to suit.
• Heavy Gauge wire crimper (the hammer kind)
• LOTS of Rosin-core flux solder

Here’s some photos of the set up from the build process, and some from how it sits today.
Still, happy to field any questions and help anyone along with this project.

THANK YOU ALL for the help and encouragement in this project, and over the years.

 

[Taylorious]

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