Arb 50L, raptor agm, Odyssey agm...easiest link??

[Jspeers89]

I have read several threads but wanted to double check my thoughts and get the best and easiest connection for my arb fridge. In the past I ran my fridge 24/7 of my starter battery which was an Odyssey 48-720 in my Jeep. It was wired with arb wiring kit from fridge to battery. I drive multiple times per day for work which helped recharge the battery. I never had any issues with a dead battery and I could go 3 days without starting in Texas heat on that setup which was ran for 1 year.

I have a new truck and I want to wire my fridge back up. I'm considering a slightly different approach and want the best way to set it up. My driving habits are the same as above. The Truck rarely sits longer than 12 hours without being driven. My fridge is always stocked for my kids who have more tball and baseball games than mlb players. The truck is a raptor with an oem agm battery from Ford motor performance ( not sure the maker but it's a bagm-94rh7-800). I still have my Odyssey 48-720 and want to wire this battery for the fridge. The fridge will be mounted in the back in an arb extended slide and the Odyssey will be mounted behind it in the slide.

the Odyssey will only power the fridge and my plan is to have the alternator recharge the battery. I am looking at the blue sea add a battery kit but I have seen alot of threads and use with the blue sea ml-acr being used.

What would be the best product to use to have my starter battery as a starter, my aux battery for my fridge, alternator to charge both. I also hope that the system will be automatic and i do not have to turn on or off the system manually. Thanks for any help in helping me finalize my system. My kids are dying for me to hook the arb back up.

 

[Hillbilly Heaven]

BlueSea ACR is probably the best set it and forget it type of isolation and charging control.

Your choice of connection to control switch.
https://www.bluesea.com/products/ca...ML-ACRs?Nominal_Voltage=12&Manual_Control=Yes

 

[MANUCHAO]

I used this thread to write up my old rig.... it's going strong on 8 years now...

https://www.expeditionportal.com/forum/threads/basic-wiring-question.58695/

EDIT: A national Luna portable power pack would also be good and these can be easily switch from one vehicle to another.

 

[Jspeers89]

Battery will never come out of the truck. Plan on everything being hard mounted. If the fridge is taken out I have a battery jump pack with 22ah that makes it portable if that is ever required.

 

[Jspeers89]

So if acr is the way to go with my setup, an si-acr would be the better component over the m-acr to achieve my requirements?

Is that correct?

 

[Hillbilly Heaven]

The Si-ACR is rated for 120 AMP and the ML-ACR is rated 500 amp. The Si Automatically combines batteries during charging, isolates batteries when discharging and when starting engines. The ML will combine batteries when dash switch is in manual. When the switch is in Auto the ML will connect the two batteries when ignition is on.

Main purpose of Si is in marine use to protect sensitive electronic instruments during cranking.

There are 2 flavors one with a manual switch on the isolator itself or without. Either one will suit your purpose.

 

[john61ct]

Best is the ML line, will outlast all your trucks, and minimum vampire draw.

Pricier of course.

 

[Ducky's Dad]

Those BlueSea charging relays are great, but for simple system as you describe and not using additional charging such as solar, you might as well fit a dumb isolator relay.
Agree completely. My setup in two trucks is a Painless Performance HD marine grade solenoid, works like a charm. If you want simple, just leave the dash switch in the green light position so that both batteries are always charging whenever the truck is running, but they are always separated when the key is off. Or you can separate them while running by putting the toggle in the center position so that only the starter battery is charging. You can self-jump if necessary by setting switch to red light position, which connects the batteries even when parked. That setting allows you to use both batteries for fridge and accessories if you choose. It's simple, it's cheap, it works. And the red light setting will allow you to charge both batteries simultaneously from solar if you ever add solar.

 

[john61ct]

I prefer solutions that gracefully allow for expansion without needing to replace and toss stuff out.

No one's mentioned that getting the deep cycled battery back to 100% Full takes over five hours, not many drive that much many days per week, best if free camping much face up to the fact you'll want solar down the road.

But if not, or as a temporary measure, yes, a $50 ignition-keyed solenoid will do.

 

[Jspeers89]

I am on the fence of adding a175 solar panel at some point attached to a rack above the bed cover. So with that possibility it sounds like id be better off with the ml from blue sea.

 

[Rando]

The SI-ACR is only about $80, which is not much more than high quality solenoid (and actually less than the painless one), so you may as well use that. That way you are future proof for solar or an on board charger, and you don't need to tap an ignition wire. The ML is definitely nicer, but also much more expensive and likely overkill for your application.

 

[john61ct]

Just carry jumper cables with the smaller amp models if you ever need to crank off House.

The bigger ML lets you self jump through the ACR.

 

[luthj]

The SI-ACR is 120A continuous, but can handle 210A for 5 minutes, or probably 300A for 30 seconds. That should be enough for a boost start. 300A is enough to start most anything less than a semi-truck? The voltage drop across the wiring (and ACR) may limit your starting current, so obviously choose wiring and fuses that can handle the task a 150A ANL fuse should be fine with 2 gauge or larger. The 150A ANL fuse will handle 200-250A for about 20 seconds without blowing.

My 2.7L diesel needs about 150A for 5 seconds to start. The current will spike to about 250A for a second during starter spin up. A glow plug cycle uses about 60A for 10-60 seconds

I have not looked into them, but there are some decent DC-DC (battery to battery) chargers in the 10-25A range. These may provide better battery life in a fridge only situation (no solar).

A 50-100W panel on the roof would cover the majority of a small fridges needs (depends on size and sun exposure, no shading!) and will make the Aux battery last a long time, as it will get a full absorption charge. If your new trucks alternator voltage is at least 14.3V, this is probably not strictly necessary assuming your Aux charging wiring is sufficient to keep drops under .15V at 10A

 

[john61ct]

The SI-ACR is 120A continuous, but can handle 210A for 5 minutes, or probably 300A for 30 seconds. That should be enough for a boost start.

You're right, should be, as long as not too big a diesel and not cranking too long at a time.

Vendors other than Blue Sea I'd be less trusting of their ratings, actually testing with an infrared gun would be advised when close to the limits.


> The current will spike to about 250A for a second during starter spin up.

Probably much higher, accurate equipment to measure really short spikes costs thousands.


> I have not looked into them, but there are some decent DC-DC (battery to battery) chargers in the 10-25A range.

Sterling's best, 120A current max, 180A coming soon?

But need an expensive bank to justify the investment.

 

[Jspeers89]

Would a DC to DC charger take the place of the blue sea isolater/ setup?