Components Required for Dual Battery System?

CoronaRaptor said:

You mean like 6volts to 12volts or visa versa? That's the only two I know of.

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24 and 48 are in use for some vehicles for some things as well.

There is a user named TVSJR on the F150 forum who swears up and down in multiple posts that you must disable the BMS, even if running a smart isolator. Here's a couple of many.

https://www.f150forum.com/f118/dual-battery-setups-367151/

https://www.f150forum.com/f118/dual-batteries-2018-3-5l-eb-423565/

There also seem to be people doing this successfully without disabling the BMS, like this gent on youtube:


I just don't know what to believe.

Check out the offerings from redarc. Dc to dc with optional solar inputs as well. From what I have read, the battery charging system does not like an isolator as it will see the load and then the “disappearance” of that second battery load will confuse the algorithms.

Dino. Check out my posts on dual battery install. I’ve run both AGM and now a Battleborn LiFePO4 battery. I run an ARB Elements with mine.

I posted on the Expedition Portal forum as well. I’m in remote West TX with only spotty phone and no internet so can’t research for you.

I highly recommend that you use a Hellroaring solid state isolator. Made in Montana and the best out there. Key words are “solid state”.

https://hellroaring.com/

They are high end but so is your Raptor.

Also the owner of Hellroaring is happy to talk to you on the phone. You can’t get that on Amazon.

Note that wiring advice on these forums is not always accurate and sometimes dangerous.

Talk with actual experts like Hellroaring and Tony Candela.

Tony also answers the phone: https://ceautoelectricsupply.com/

Good info guys. I’m adding a second battery and was curious of what others have done. I’m running front and rear winches and though it wouldn’t be a bad thing. I’m currently running 2/0 gauge wire to the rear winch, so that’ll go directly to the rear battery and the rear winch will connect to that.

I have a Blue Sea 7620 arriving next week. It has a 500A continuous rating and a 1450A rating for 30sec. It has a remote mounted 3-way switch that allows you to run in 3 different modes.

1. Auto mode. This will couple the two batteries when the truck is running to keep the aux battery charged, but then disconnects them so you can pull power from the aux battery without draining the main starting battery.

2. Manually connected override. This allows you to manually couple the two batteries. Basically you could instantly have a jump start. I’m planning on running in that mode while winching. Then I will get both batteries at either the front or rear winch without having to worry about them auto disconnecting when the voltage drops due to the load of the winch running.

3. Manually de-coupled. Just the opposite. It breaks the connection between the two batteries.

I disabled the bms stuff through FORScan earlier this year. That would be a necessity I would think if you’re running something like the 7620 as it auto couples when the voltage goes about 13.5v. So if the bms stuff is still enabled, it would disconnect the two batteries while driving down the road if certain parameters are met.

I’ll have to check out that hellroaring stuff. Sounds cool.

Good info here. Thanks to everyone contributing. Here are some recent conclusions from my research

1. I don't wish to disable the BMS. I am an experienced Forscan user, but I understand disabling the BMS trips a DTC (though not a CEL). Whether it's real or not, I am apprehensive about taking it to the dealer for service, they see a DTC for the BMS being disabled, and they see my dual battery system installed. I think there is a non-negligible chance they would deny any warrant work on the electrical system, whether or not my stuff actually caused it. Yes, I understand there are laws that they have to prove my stuff caused it...yadda yadda yadda...but it will be my PITA to deal with, and I don't want to deal with that.

2. Since I am keeping the BMS, I have accepted I need to charge with a DC-DC charger and not from the stock charging system. I actually like this circuit design anyway, because the only time the truck system and the aux system are linked would be in an emergency when I throw the switch to link the two to jump a dead start battery from the aux battery.

3. Redarc seems to be pretty experienced on this front. They even offer wiring diagrams. Right now I'm working off the one attached. I plan to use a manual switch from Blue Sea Systems rather than the momentary switch Redarc recommends.

4. Right now I'm designing around an Odyssey 94R AGM battery, the Redarc 1225D, Redarc's SBI 12 Isolator, the fuses Redarc recommends, breakers from Blue Sea Systems, a manual override switch from Blue Sea Systems, and hopefully adding a 1000W inverter.

5. My vision is to mount this in a Pelican V550. I understand I will need to ventilate the box with some DC fans.

6. Aux system will be connected to the start system for emergency jump start via a 13.5' run of 1 AWG. Blue Sea Systems' circuit wizard helped me determine that 1 AWG is sufficient for the worst case amperages.

That's where I'm at now. Advice welcomed.

Oof, the diagram I am working from that I forgot to attach...

The Hellroaring units are designed to work with modern vehicle charging systems. It’s quite a bit simpler than the REDARC. Read through the HR site before you make your decision.

HR has actual design engineers who will field your calls.

If you are not going to winch all you need is the isolator. If you want to winch then you’ll want a combiner.

Why not carry a Lithium jump pack instead of the added complexity of a combiner? You are far more likely to run the AUX battery down than you are the starting battery.

Batteries: for AGM consider Northstar or X2 Power. Both are premium.

Buy the finest stranded wire you can, tinned copper heavy wall lugs, a quality crimper, adhesive lined shrink, wire dressing, etc.

I buy my fine stranded wire either from Polarwire in Alaska (premium wire) or from Tony Candela in AZ (ultra premium wire). Both companies have wire, lugs, shrink and crimpers.

Polarwire gets my solar business, Tony gets my automotive business.

Buy your lugs from the company you buy your wire from. Note that Tony’s wire is thicker for the same gauge, so buy his lugs if you buy his wire.

Be aware that you need to drive a lot every other day or so to keep your AUX battery charged. Consider adding solar if you want to stay in one place longer.

I’m using a 180 watt folding ZAMP system, but I run two ARB fridges and two battery banks for basecamp. I think a 100 watt system would be plenty for the one battery and one fridge.

I use a Walmart battery box to house my Lithium AUX battery for Raptor. I added charge ports to the box for the ARB.

My battery and fridge are in the bed. Twenty feet or so of 8 gauge from isolator in the engine compartment to the bed. Installed a hole in the bed to run the wires. Used Anderson HD connectors to connect to the battery box. Simple and clean. Both fridge and battery box come out of the bed in minutes and get put in the shade for base camp. The fridge uses way less power when in the shade.

I’ve got HR isolators in both of my trucks now...they work great.

The isolator in the Raptor is tucked up in the corner of the passenger side firewall. You can barely see it. I installed nutserts in the firewall to mount the isolator.

Use rubber or plastic grommets/bushings when you pass wires through holes in metal.

Use some kind of wire dressing over your wires.

Have fun with the install!

wheelman55 said:

The Hellroaring units are designed to work with modern vehicle charging systems. It’s quite a bit simpler than the REDARC. Read through the HR site before you make your decision.

HR has actual design engineers who will field your calls.

If you are not going to winch all you need is the isolator. If you want to winch then you’ll want a combiner.

Why not carry a Lithium jump pack instead of the added complexity of a combiner? You are far more likely to run the AUX battery down than you are the starting battery.

Batteries: for AGM consider Northstar or X2 Power. Both are premium.

Buy the finest stranded wire you can, tinned copper heavy wall lugs, a quality crimper, adhesive lined shrink, wire dressing, etc.

I buy my fine stranded wire either from Polarwire in Alaska (premium wire) or from Tony Candela in AZ (ultra premium wire). Both companies have wire, lugs, shrink and crimpers.

Polarwire gets my solar business, Tony gets my automotive business.

Buy your lugs from the company you buy your wire from. Note that Tony’s wire is thicker for the same gauge, so buy his lugs if you buy his wire.

Be aware that you need to drive a lot every other day or so to keep your AUX battery charged. Consider adding solar if you want to stay in one place longer.

I’m using a 180 watt folding ZAMP system, but I run two ARB fridges and two battery banks for basecamp. I think a 100 watt system would be plenty for the one battery and one fridge.

I use a Walmart battery box to house my Lithium AUX battery for Raptor. I added charge ports to the box for the ARB.

My battery and fridge are in the bed. Twenty feet or so of 8 gauge from isolator in the engine compartment to the bed. Installed a hole in the bed to run the wires. Used Anderson HD connectors to connect to the battery box. Simple and clean. Both fridge and battery box come out of the bed in minutes and get put in the shade for base camp. The fridge uses way less power when in the shade.

I’ve got HR isolators in both of my trucks now...they work great.

The isolator in the Raptor is tucked up in the corner of the passenger side firewall. You can barely see it. I installed nutserts in the firewall to mount the isolator.

Use rubber or plastic grommets/bushings when you pass wires through holes in metal.

Use some kind of wire dressing over your wires.

Have fun with the install!

Click to expand...

Lot of helpful info there. Thanks so much! Especially about sources for wire components. It's tough to find quality stuff on Amazon sometimes. Now let me tackle some of your questions.

1. I am carrying a lithium jump pack: A NOCO Genius 1500 Amp model. I planned on adding the circuitry to use the aux as a jump because I just hate to go through all this trouble and this cool thing I'm building can't be used to jump start a dead truck. Of course, it's in a Pelican case, so I could just make a "jump adapter" with big cable clamps on one end and an Anderson plug on the other that plugs into the aux system's Pelican case. Maybe that's a better solution than running a 1 AWG pair 13.5' down a frame rail and into my bed.

2. My plan for camping is for the Pelican case to remain secured in the bed. I plan to run 110V and 12V lines from the Pelican case to tech plates on the BuiltRight system near the tailgate. I will also have a remote switch there (near the tailgate) to turn on the inverter. So my DC-DC charger will run anytime ignition is ON. Inverter will only run when manually switched on from the tailgate.

3. Any recommendations on cooling the Pelican case? Right now I'm thinking two 120mm USB fans (one pushing, one pulling). I'm uncertain on whether they just need to run when the inverter is on, or whether the DC-DC charger will need cooling as well. Any advice here?

This is what I used to build my dual battery setup, and i might be biased buts its the cleanest dual battery I've seen in a raptor.

REDARC Battery charger (BCDC1250D) x1 https://redarcelectronics.com/products/dual-input-50a-in-vehicle-dc-battery-charger 366.07

Genesis Off-road single battery holder (153-STBK) x1 https://www.genesisoffroad.com/universal-single-battery-kit 160

Odyssey 34-PC1500 Battery (34-PC1500) x1 https://www.genesisoffroad.com/group-34-battery 296

BEDSLIDE ALUMINUM BED INSTALL KIT (BSA-HALUMKT) x2 https://www.bedslide.com/i-30497593-bedslide-aluminum-bed-install-kit.html 16

6 gauge wire from main battery to REDARC

60A FUSE KIT (FK60) x2 https://redarcelectronics.com/products/60a-fuse-kit 43