Single vs dual batteries, winching, house bank, and charging

[IdaSHO]

Currently laying out the electrical requirements for a 2011 Super duty gasser (6.2)
Though Im struggling a bit with the camper/house battery bank charging as well as the winch power needs. I welcome any input.

The truck has a 150A alternator and group 65 ~800 CCA Battery, stock.

Truck will be fitted with a X20 Smittybuilt 15500 winch
Truck will be used for high amperage charging of 230AH camper/house battery bank

So I'm considering options right now.

Dual alternators:
One alt for OEM + winching duties, and one for managing charging duties for the camper bank.

Dual batteries:
Normally used for heavy winching, and/or aux battery draws like a fridge.
The group 65 battery, according to Smittybuilt is enough, and I already have an aux bank for aux draws. So Im leaning away from dual batteries.

Camper bank charging:

In the past, and currently with the old truck, I can fast charge the camper bank with little more than a 200A continuous duty relay, some heavy wiring (2AWG) and a switch. While this works, it can be a real workout for one alternator, and I'm not convinced it can charge the camper batteries nearly as well as it does under-hood batteries due to different battery types, and the distance away from the alternator. So I'm considering dual alternators. There looks to be room, though it would be 100% custom.

But how about a dedicated battery-to-battery charger (sterling) instead of a custom dual alternator setup? This would provide intelligent and “proper” high amperage charging of the camper bank, all the while being lighter and considerably more simple than dual alts, though pricey.


Any comments? Or considerations I’ve missed?

Thanks

 

[john61ct]

You don't need a second alt.

Unless you will often be on mains or drive in 7-8 hour stints, you will need solar to get House bank to Full.

Huge wire will help prevent voltage drop, but the Sterling is a better bet for precise care. Located at the target bank.

 

[john61ct]

You may want a dual battery up front for heavy winching needs. Although deep cycling, best not to run off House.

A pair of Odyssey PC-2150M as one front bank will give true Dual Use, the engine cranking totally trivial.

Maybe carry a HD lithium jumpstarter for belt & suspenders, or put a LVD on one of the pair keep it from running down too low when winching.

 

[luthj]

With a 230AH house bank, a 40-60A dc-dc charger would be good, and should be well within the limits of your factory alternator. With a lead bank you won't max out that DC-DC for very long anyways.

I second the suggestion that you will definitely need a secondary charge source (solar etc) if you want to keep the batteries alive more than a year or two.

You don't strictly need dual batteries, but with that large of a winch, you will see over 700A. Go with big cables. This means all the winch runs. Most of those winches are really undersized, even with the intermittent usage... If you plan on doing a lot of winching in one go, that can draw down a smaller battery quite easily. The voltage sag from a single battery under such load after 30 second or so can really drop a winches output, and make it heat up. It really comes down to how often, how long, and how close to the rated load you will winch.

If you go with dual batteries, make sure to balance you wiring, otherwise you will have one battery supplying 500A and the other 200A or similar.

 

[IdaSHO]

Already have 400 watts of solar via the camper, and is another benefit of the stupid simple continuous duty relay; recharging the truck battery.

I guess another option I forgot about that I had considered was simply a larger single truck battery. A group 31 would fit pretty easily.

 

[luthj]

If desired, you can fit a 5-10A B2B trickle charger for topping off your starter. Just have it disabled when driving.

A 230Ah aux bank can supplement winching needs if wired correctly. A ML-ACR would handle the load without issue. You would need some serious cables, 4/0 or so.

 

[john61ct]

The dual batts I reco'd are G31.

Obviously the alt should be running to support the winch load.

Only use the House bank for winch support with a good SoC meter unless it's just rare emergency use. Much better to keep that huge load separate to a dual bank used also for cranking.

If you want to ever combine the two banks in a pinch, go with that Blue Sea ML 500A model.

 

[LandCruiserPhil]

Just run your duals batteries parallel and be done, why complicate things? Unless you plan on doing extended multiable winching exercises you will be fine with the stock alt.

 

[Buliwyf]

Standard battery and the HD alternator is fine for me. Just stick to decent quality batteries. I don't want my house batteries to have anything to do with winching.

How much winching do you plan on doing? Generally, fullsize's are easy on winches, because you're just stuck and looking for a 10' tug. You don'y need ton of battery for that. Besides, when I'm stuck enough that I need multiple pulls. There's a ton of time re-rigging the cable in different directions, or some shoveling to do between each pull.
I don't even have an electric winch anymore, and use a highlift.

Sometimes jeep guys know that there's 10 miles of good trail on the other side of a mile tall hill that their ride can't hardly climb. So they winch a ton more, and need the batteries to do it. The difference between a simple recovery tool, and a complete crutch.

 

[Ducky's Dad]

The group 65 battery, according to Smittybuilt is enough,

That info is probably not reliable if you have to do any serious winching. As an example, the 3G Power Wagons came from the factory with a 160amp alternator, Group 65 FLA battery, and an OEM-spec Warn winch that was nominally 12K but spec'd out with 15K components (probably downrated by the Dodge lawyers). Yes, you could winch with that setup, but long, heavy pulls taxed the system. The standard solution was to replace the G65 with a quality G31, and put a brick on the accelerator pedal while winching. Many of us upgraded with dual or triple batteries (depending on how many other items were running) and higher output alternators. Alternator upgrades are fairly simple and not too expensive. My PW now has a 270amp alternator that runs on standard pulleys and belts, and triple batteries so that I can run the fridge and the winch and still have backup battery power if needed. Seems to me that, for your situation, a good G31 is mandatory, dual batteries are a smart move, alternator upgrade highly recommended but not absolutely necessary. I see solar in your future.

 

[dwh]

I'd bump the engine battery to a G31 and swap out the 200a dumb solenoid for a 500a BlueSea ACR.

A) That will allow your solar/shore charger to automatically keep both house and engine topped off.

B) Normally the engine battery will get topped up after starting in a few minutes and after that the majority of the alternator output will end up going to the house battery.

C) When winching, if the winch load drops the voltage enough (it will), the ACR will disconnect the house battery.

D) Unless your chassis voltage is usually below 14v, the DC-DC charger isn't going to make a big difference.

E) The big wire to the house battery is only important if the house battery is sucking a lot of amps, but as the battery voltage rises, the amps flowing will drop, so the wire will be more than ample to insure a full charge...IF you run the engine enough hours for the battery to fully absorb. That will still be true with a DC-DC charger.

F) In a pinch, you can force tie the engine and house batteries to provide more reserve capacity to the winch.


I wouldn't bother with a second alternator unless you plan to do a lot of winching, in which case I'd run them in parallel to double the amps available for winching.

 

[IdaSHO]

Thanks everyone. Looks like Im on the right track, so far as I resist to over complicate things

The truck will not see serious winching. More along the lines of slide-offs and lightly stuck, self recovery, in mud and snow.

For now Ill stick with the single OEM alt and battery, and once the winch is installed Ill just see how it fares.

Ill also stick with my dumb solenoid for charging, and forget about any dc-dc chargers.

Ill take a look into the Blue Sea ACR though. It would save me the trouble of a toggle switch to combine both banks.

 

[Umbrarian]

I have gone through many combinations and have settled on:

Single Alternator, Dual Battery to run the vehicle. This is how it left the factory.

Second Alternator, 3rd Battery to run other vehicle accessories, Winch, O/R lights, HAM Radio, etc.