Looking to get some help on a dual battery set up to make sure I have this ran right in my 4runner or if I'm doing something wrong. I'm sure I'm missing something.

Starter
Warn EVO 10-S Winch (Max amp draw of 358-Amps) Should just install a shut off switch for when not in use or a fuse?
Positive cable to dual battery What fuse do I need on the starter's positive terminal for a FT840-24F to FT750-35 Battery? 6-7ft could also us recommendations on AWG size.

Dual
125-amp feeds power switch (Aux lights added)
60-amp feeds BCDC Charger

Thanks
Josh

 

I can't tell exactly what you are trying to do or are asking.

Maybe this will give you some ideas:

Back in 1983 I put a dual electrical system in my '75 Ford Bronco. The auxiliary system was primarily for running lights and radios and I wanted to be able to run them when the engine was off without worrying about draining my battery to the point that I couldn't start the vehicle, since I was heavily involved in search and rescue at the time and so I was out in the deep boonies -- and the truck was an automatic, so push starting it wasn't an option.

So I put in two batteries and four isolators so that I could selectively tie either battery to either electrical system. But then the question becomes how do you power the isolators, since you can't keep them engaged for an extended period of time when the vehicle is off otherwise they will drain the battery. Also, there were circuits that need power continuously, such as the clock and a couple other things that I had. That latter problem was easy, I tapped off each battery to an AlwaysHot circuit via two diodes so that one battery couldn't drain the other. Power for this circuit always came from the stronger battery. Since these were all items that were already powered continuously, the draw was low enough that draining the batteries wasn't a practical concern.

But powering the isolators was. I couldn't use my AlwaysHot circuit because then the isolators themselves would drain both batteries. The solution to that, however, was also very simple. Just power each pair of isolators from the battery it served. The only concern here would be if one battery was so heavily drained overnight that it couldn't turn on it's own isolator to connect it to the main system (after the engine was started off the other battery) to be charged. But I figured that if it was drained that badly, I probably should be thinking twice about connecting in the first place. I thought about incorporating a switch into my control box that would let me choose which battery powered each pair of isolators, but decided that if I really needed to do that, I should be willing to pop the hood and physically jumper across just as I would if the dead battery was in a different vehicle.

The system worked beautifully.

 

I can't tell exactly what you are trying to do or are asking.

Maybe this will give you some ideas:

Back in 1983 I put a dual electrical system in my '75 Ford Bronco. The auxiliary system was primarily for running lights and radios and I wanted to be able to run them when the engine was off without worrying about draining my battery to the point that I couldn't start the vehicle, since I was heavily involved in search and rescue at the time and so I was out in the deep boonies -- and the truck was an automatic, so push starting it wasn't an option.

So I put in two batteries and four isolators so that I could selectively tie either battery to either electrical system. But then the question becomes how do you power the isolators, since you can't keep them engaged for an extended period of time when the vehicle is off otherwise they will drain the battery. Also, there were circuits that need power continuously, such as the clock and a couple other things that I had. That latter problem was easy, I tapped off each battery to an AlwaysHot circuit via two diodes so that one battery couldn't drain the other. Power for this circuit always came from the stronger battery. Since these were all items that were already powered continuously, the draw was low enough that draining the batteries wasn't a practical concern.

But powering the isolators was. I couldn't use my AlwaysHot circuit because then the isolators themselves would drain both batteries. The solution to that, however, was also very simple. Just power each pair of isolators from the battery it served. The only concern here would be if one battery was so heavily drained overnight that it couldn't turn on it's own isolator to connect it to the main system (after the engine was started off the other battery) to be charged. But I figured that if it was drained that badly, I probably should be thinking twice about connecting in the first place. I thought about incorporating a switch into my control box that would let me choose which battery powered each pair of isolators, but decided that if I really needed to do that, I should be willing to pop the hood and physically jumper across just as I would if the dead battery was in a different vehicle.

The system worked beautifully.

I have a RedArc BCDC charger that will charge and limit pull from the starter to the Aux. My main question really is what size of fuse would you use on the positive connection at the main battery to the secondary battery?

 

The installation manual for the winch doesn't mention a fuse or show anything like that meaning it should be in theory just fine without it. Winches are usually run by high power relays normally used for starters and they last for years without a fuse. If you feel the need a 350 amp fuse will probably work just fine unless you're running your winch for a super long time. Fuses will allow a percentage of over current for a time before blowing.

As far as between your main and secondary this https://cdn.intelligencebank.com/au...q/original/BCDC+Dual+Input+Instruction+Manual would leave me to believe a 60 amp fuse is what you need.