Dual Battery Setups! Let's see them! Multiple Batteries Thread!

I used 200A. Find out the max your wire can handle (or minimum rating of any components in line on the charging circuit) and fuse for that.

 

Your planning on putting your aux battery in the bed correct? I estimate that to be a 10-12' run. Use this chart to determine what the amp loads for the various wires sizes are for the number of feet in your run. Looks like 1/0 at 12' is good for ~200 amps.

 

Yeah, I'm going back and forth between putting it in the bed or just trying the Columbia overland dual battery mount...

I use a similar chart when wiring, but I'm trying to figure out what size fuses to use for the positive connections from the batteries to the solenoid/relay.

 

Heavy batteries under the hood destroy stuff, anywhere but under the hood!

0/1 is sufficient from the bed, I have my set up on a 300 amp fuse. (Three 100A mini ANL fuses vice one large to lower resistance) I have .02 voltage drop at that distance.

 

Guess yours is wired differently than how I plan. Do you have all three coming off one battery to the solenoid?

 

They are all housed in the same in line holder. Batteries 1/2 feed into my bank isolator switch and the output is fused to the factory underhood connections.

 

So you have no fuses between your batteries and your bank isolator switch?

They way the diagram I'm looking at shows, it wants you to put a fuse between the positive post on the battery and the isolator switch for each battery.

The fuse locations circled in green are the ones I'm trying to figure out what size I need for.

 

so if the secondary battery is in the bed and I have a winch, how would I wire that up because the winch wires need to be wire directly to the battery or am I overthinking this?

 

No fuses between the battery and manual isolator switch. All the power to the truck is fuse protected except for my winch because there is not much available that can handle 500 amps. I have it on a HD ON/OFF Switch to kill power in a runaway winch situation.

 

Ah, gotcha. So you're not worried about the manual isolator switch melting? All the research I find is conflicting where same say you have to have fuses and others say it doesn't matter for the exact reason you said.

Not sure if you saw my edit, but these are the locations I'm talking about.

The fuse locations circled in green are the ones I'm trying to figure out what size I need for.

 

Yeah not worried about it frying, it's rated for much higher amps than the wire is.

You could look into a marine style fusible link option right off the battery, if the blue sea can handle 500 continuous amps you can fuse it at or less of course.

 

Hmm, what is yours rated for?

Guess I'll just go ahead and do a 250 amp fuse for each battery. Only ~$15 a piece so it can't hurt.

 

Depends on how you want the winch wired...lots of variables. I wired my winch directly to my aux battery.

You need to factor in max amp draw at load to figure out the minimum size wire needed. Mine ended up needing 4/0 to be safe.

 

Battery bank switch, 320 amps continuous 600 amps at 5 minutes, 1000 amps for 1 minute.

The HD winch on/off is 600 continuous, 900 at 5 min. Overkill but it won't be a failure point on critical recovery gear

 

looks like according to the wire diagram 1/0 since the aux battery is going to be in the bed.

 

Why not run the winch off the starter battery, especially if you have in under the hood?

 

This is curious. Conventional wisdom says to protect the run. Is yours a very short run? like 12" or less from either battery to the ML-ACR?

 

Mines about 18-24" and I've got it fused

I would do this too. I think AaronArf was going to run his winch off a battery in the bed and use like 0000 gauge cable to handle the amp load

 

that is were it is now but with all the shit I have under my hood the only location that a battery could go is in the bed. I rather have it hook up to the aux instead of the main battery but I guess it wouldn't hurt the main battery right? and hook everything else to the aux.

 

Are you referring to the starter battery? Are you moving it to the bed?

Why not leave the winch connected to the main/starter battery and leave it in the stock location? The wire run from there is shorter so the wire requirement isn't as high plus that battery is connected directly to the close by alternator.