Thread: Anyone running a dual battery setup?

Don't have any pics available. Mine ran a second batt in front of the air box. It had a simple Narva isolator, but I bought one of Tim's SC-80s for it, which is now destined for the OKA. The 2nd batt ran the winch, with an under bonnet cut off switch, and an Anderson plug in the back for fridge and compressor, and some lights. Simple, effective setup, if you aren't tying to take your whole house with you.

Tim is Drivesafe on here. Great guy, great product.

Ta. Will look into it. I just wanna run a few things. But mainly just for a winch!

Originally Posted by Pr0ko

Ta. Will look into it. I just wanna run a few things. But mainly just for a winch!

You'll still meed an isolator. Talk to Tim.

Originally Posted by Pr0ko

Ta. Will look into it. I just wanna run a few things. But mainly just for a winch!

Winch should always be wired to the main battery.

Originally Posted by Tombie

Winch should always be wired to the main battery.

Not arguing, Mike, but why? My D1 was wired to the aux ( not AGM or anything ) with a solenoid that could bridge the two. My OKA has the winches wired to the aux batts as well. That car is getting rewired so it has an isolator and I'd like to get it right.

Just get a basic VSR (I like the redarc SBI12D), wiring is quite simple.

I’m with Tombie, wire you winch to main battery…..assuming your second battery is going to be an AGM.

Hi jay Tee, and the standard rule of thumb is :-

Anything that is only run while the motor is running, should be connected to the Cranking battery.

Anything that is to be run when the motor is off, should be connected to the Auxiliary battery.


BUT, with something that draws such high currents, like a winch, or a large 240vac inverter, should be connected to the cranking battery for a good reason.

It keeps the cable run for all power sources to a minimum length.

By keep the distance from each power source to a minimum length, you not only reduce the voltage drop of the whole circuit, but by keeping the voltage as high as possible, you increase the efficiency of the operation of the device being powered.


This in turn means the device does not work as hard todo the same job and this will help the operating lifespan of the device.

Passengers side area in front of air box is idea and easy peasy to set up an Aux battery system.

Easier version is to use a NS70 sized battery, which requires the least mods to the area, but a N70ZZ could be squeezed in which requires more mods, especially moving the power steering reservoir out of the way.

When I fitted mine, I already had a battery to go in and used that, but if you buy a battery better to have an 'L' type battery just for a bit more 'safety'

An L battery means the posts are the other way around.. that is a non 'L' battery has the positive terminal on the right hand side if the battery posts are set up towards the rear of the battery when set up long edge across the car(as discos have).
If you look at your main battery you can see how the terminals are set, with the positive closer to the motor.
On an 'L' type battery the positive would be on the quarter panel side of the battery. Don't fit the battery with the posts closer to the grille, better towards the firewall.

Reason I say this is, so many times I'm doing some work and have a spanner or bar or whatever and knock it and it falls onto the terminal AND touching the body and ... ZAP! ... arrgghhh! ... again. And yes I do have the protective cap on the terminal!
If my Aux ever dies, I'll replace it with the L type terminal layout.