Where to mount battery isolator

I am in the process of adding a second battery but I do not have a place to mount the isolator inside the engine compartment. I was thinking to mount it behind the grill on the drivers side of the front clip. That is the only metal place to mount it. My question is how sensitive are these things to the elements? It will be somewhat shielded from direct contact, but will still be somewhat in the open. I was also thinking to cover the contacts with RTV to protect against shorting. This is realy the only option unless I go remote and run a bunch of extra cable. Any thoughts?

take out your inner fender, mount it between the fender and the "inner" metal piece

Get a marine grade one and dont worry about it.

Already got an isolator. I will probably do the inner fender trick. might try tomorrow. I just got done mounting a front receiver for my winch. I mocked up the location for the battery and I think I'll be able to get away with turning the washer and coolant tank 180 degrees towards the motor and I will make a metal bracket for that and the charcoal filter thing that sits on the front clip.

you'll have to use some sort of epoxy or 3m tape to do it how i am thinking

expo5.0 said:

you'll have to use some sort of epoxy or 3m tape to do it how i am thinking

Click to expand...

Epoxy or tape for what? To mount it? There is some thin sheet metal in there I will be able to mount to.

if there is room go for it- the spot i was thinking of i don't think you can reach without removing the fender to drill holes.

Well now the debate continues. I went and picked up some liquid tape from Home Depot. It says it water proofs and protects and is good for marine use. So I think I may go with my orginal plan and mount it to the front clip behind the grill.

Here is where I mounted it. It fits perfect behind the grill and with the liquid tape, I think it will be ok.

Well both batteries are in and the isolator appears to be doing its job. I fabbed all the relocation brackets for the washer/coolant tank(Turned 180 out), charcoal cannister(Fule tank vent), and made brackets to support the battery tray. Almost looks like it was meant to be that way. Did it all with the support of Home Depot and Pep Boys . Next will be the quick disconnects for the winch to the secondary battery. You can just see the fins of the isolator behind the grill on the drivers side. Yea I know, she needs a bath. Thanks for the ideas.

im doing a dual battery set up as well, and was wondering is the stock alternator ok?

What is that white wire doing on top of the battery on the passenger's side? From the picture, it looks like it's shorting both terminals. I know that can't be possible. What is your second battery powering? Do you have power accessories, like a winch, stereo, lights, etc? To answer Badash's question, do you have a 95, or 130 amp alternator? What will you be powering? They make different amp ratings for isolators, so try to use one that is a little above the stock alternator rating if possible.

The white wire is the alt lead coming from the solonoid mounted on the fender. After I hooked everything up yesterday, there was no power on the primary battery. So it would seem that I am only isolating the aux battery(BAT2) and the primary is running directly off of the Alt. If that is the case, I should still be able to add a 3rd battery in the rear to support a power inverter.

Badash,
It all depends on what you are doing with your system. I went to the junkyard and got a 130 amp alternator from a newer Explorer. If you isolate the batteries, you need to buy an isolator that can handle your size alternator as far as I know. You can buy aftermarket alternators that go up to 250 amps if you need it, but they are spendy.

Here are some battery isolator wiring diagrams:

Some set ups use a high current relay to switch power instead of using a diode style isolator. Here is a relay wiring set up:

Well I know now what needs to be done. Having that wire from the battery to the solonoid makes the isolator think that the alternator is on and I have voltage to both sides with the key off. I will have to run power to the fuse block directly to the battery and disconnect it from the solonoid.

I hope the dual battery schematics were helpful.

Yea thanks. Now looks something like the first one. Kinda thru me off how its drawn but basicaly the same except there is no second lead coming off the alt. That is the Delcotron CS thingy. Thanks again.

This is basicaly how I did it.

Here is some info you may find useful.
http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html
This one will calculate the voltage drop.
http://www.powerstream.com/Wire_Size.htm
You will also have a .75 VDC drop across each isolation diode in the circuit.

The longest run I have is to my amp which is no big deal. The run to my winch is about 3 to 4 feet and yes I am seeing the .75 drop more or less. Everything seems to be running good now. Thanks for the replies.