Battery Separator Relocation?

[BrianW]

Current situation (pardon the pun): My 2011 Indiana-built SMB has the SurePower 1315-200 battery separator installed under the gaucho with the house batteries all the way at the back of my (EB) van. They wired it with the automatic start assist via a wire tapped into the actual starter under the van. The unit was originally screwed into the gaucho base, but at some point the screws pulled out and it’s just lying on the floor inside the gaucho with the hot cable terminals unprotected (I put some gorilla tape over them as a temp fix). The cable they ran from the engine bay to the separator appears to be 4awg at best, under the 2awg that Sure Power specs for a 10-20’ run. Not much I’m going to do about the wire gauge at this point. It’s been ok for 11 years so far. I have three Duracell Group 31 AGM batteries (105ah x 3) and a 2000 watt inverter/charger.

Relocation: I’d like to relocate the separator to the engine compartment as part of my efforts to clean up the SMB wiring spaghetti under the gaucho. Also, from what I’ve read it’s better to have the separator close to the starting battery/alternator. I also want to disconnect the auto start assist and add a momentary switch instead. My old 98 SMB had the separator under the hood and it didn’t cause any issues.

The Questions: Any red flags to installing this SurePower unit under the hood? For those who have it there, where is it installed? And where did you tap into a power source for the start-assist circuit? In his seminal treatise on battery isolators, etc., @Scalf77 suggested a wire at the steering column, but I’ll have to check if my 2011 5.4 has that same wiring. Ideally, I’d prefer something easier to access in the engine compartment.

In the future I hope to add solar and upgrade to a magnetic-latching Blue Sea unit, but for now I’m not eager to drop $200+ on a new separator when my present one works ok.

I appreciate any and all thoughts!

[Scalf77]

I have never installed one inside the engine compartment, the added engine heat would be my only concern. Being that if you do that you will also need to move cables, you might think about moving to the correct size while your doing it. And, to be honest I would just move to the Blue Sea unit at the same time. I really don't think that there is any real advantage being closer to the starting battery, from a operational standpoint.

If you are just using a monetary switch all you need is a always 12 Volt input, it doesn't need to be driven by the "start circuit". There are plenty of fused circuits that are a few fused circuits are 12 "start circuit", that you could tap into. But, as I said you don't really need to anyway, moving to a momentary switch.

-greg

[gahamby]

I had the same fall off problem with my Sure Power. Sheet metal screws into MDF are not much good. I remounted it with through bolts. Later the Sure Power separator failed and I replaced it with a Blue Sea 7622. I found heat to be a factor with the Sure Power under the Gaucho. Yes SMB north did a half ass job wiring my van also. I put a 100A circuit breaker on the hot lead from the house battery so I could work on the electrical system without having to get into the battery box to disconnect there. The Blue Sea with a switch on the dash worked great.

[BrianW]

@scalf77 Beyond the engine compartment, where would you suggest mounting it? I guess it's ok under the gaucho as is, but I wonder if there's someplace "cleaner" to locate it if proximity to starting battery isn't an issue. Blue Sea isn't quite in the budget right now as I have other things to deal with first.

@gahamby At least they installed a cutoff switch for my house batteries on the front of the gaucho. The screws into the gaucho box were a joke, even though my build has plywood(ish) cabinets and not MDF. What was really unacceptable was the uncovered hot wires that attached to the separator!

[Scalf77]

I am assuming the 4 awg comes from starter battery up through the floor under the gaucho. So you could put it any location along that path. I would find working on it under the van a pain, but it would be what it is. The elements won't help, but using dielectric grease on everything would help.

I have mounted the Surepower to a piece of 1/2 plywood, using elevator bolts because the are flat to mount the Surepower to. Then use four wood screws to mount that to the gaucho wall. I have even covered the top with plywood or lexan to protect the wires some.

IF moving eventually to a Blue Sea, it would be better under the gaucho anyway. While you are screwing with the Surepower ass a 10 amp fuse to the ground wire. (it is the only way to protect the unit as the positive contacts if fused would way to high of a rating)

While the Surepower is continuous duty. it will run warm in any event. If it is getting really hot, then it could be a sign of aging and resistance build up on the internal contacts.

-greg

[BrianW]

Good idea of the ground fuse. Will definitely do that. If I keep the "automatic" starter wire, any benefit to fusing that, too?

4awg wires is run through the firewall, under the driver-side footwell, and then (I guess) through the wall. Since the gaucho is on the passenger side I have no idea why they didn't run it down the passenger side. It eventually comes out of the wall in the gaucho on the passenger side.

Since it's all hidden behind walls, it would be a PITA to upgrade to a 0awg or 2awg (not to mention $$$), other than just running the new wire under the van. It seems the thicker cable is only really needed for the start-assist feature, so maybe I just do away with that (I've never needed it on either of my two vans and 10 years of ownership). Of course, thicker wire is always better for any charging circuit, but...

[Scalf77]

Yes, it should be fused

[Colorado_Jeff]

In my 2019 build they installed the separator under the driver seat…2+ years later they moved it inside as the terminals and/or relay had rusted and it was no longer charging my house batteries. Probably safer up inside the hood than under the van but something to keep in mind when picking a location.