Simplest Dual Battery Setup

Here's what I'm using. It's a Redarc Smartstart dual battery relay. You turn the ignition on, start your engine and 15 sec +/- this little box clicks and links your start battery to your second battery. The supply lead to the second battery has a large inline auto reset fuse at each end in case of any shorts. It was under $150 too. I'd be running your winch on your start battery, but having a matching brand and size of battery as your leisure battery as its basically running as though it was side by side. (We've had issues with trucks and tractors when different batteries are paired.. Don't ask me why tho!!) They will run a fridge fine, and then they are both there on demand for the winching..... Just my thoughts. Keep it simple what ever you do. Running a matching pair of batteries instantly gives you a spare starting battery when out bush!

I'm running a Traxide SC80 and two "Supercharge 'all-rounder' batteries". They are dual purpose (105ah and 760cca) so will happily start your car as much as they would run a fridge.

I have circuit breakers at either end and an Anderson plug at the aux battery which I disconnect from the main once at camp and plug solar directly into.

All up my kit cost about $200 from memory. Without the solar panels I get nearly 3 days out of my aux battery running an 80L ARB fridge and camp lights before I need to recharge.

My setup is switchable so I can also isolate the two batteries that way.

Cheers
Keithy

Plus 1 for the simple relay for me as well. I was a bit adverse to the flash ones with circuits for delaying the connection of the two batteries and other things. I've never had one but was concerned about the robustness of the circuits in the bush. So I opted for a heavy duty relay which is switched to on when the ignition is on. Both batteries have heavy duty circuit breakers (easy to reset). Both batteries are the same size 70a/h if I recall. When going away I throw a 100a/h into the shelves in the back and the whole set up is maintained by a solar panel on the roof. Simple is best I reckon.

look at the Ark Pack alternative to hard wired 2nd batteries .

There are threads in the D3/4/RRS forums

Robustness in the bush?! :lol:

On an Aux battery system?

Don't even consider the diodes, relays, rectifier pack, wiring connectors, fuses, fusible links, suspended lead plates, oil pressure switch, or other myriads of items that are just as vulnerable to failure which can render the vehicle Dead..

Or simple relays which can fuse in the latched position, draining both batteries...

Good to see Luddites are alive and well in the modern world :D :)

It's funny you mention Ark Packs BDB, I am using an Ark Pack (the older one, not the new expensive one) as my battery box as my aux battery lives in the back of my P38.

I like it because regardless of what your vehicle does during the week, you always have a fully charged battery ready to go via the 240v charging option.

I've simply added the Anderson plug setup for my dual batt system to the power pack. So I can bypass the 240v smart charger and use my alternator to do the rest until I'm at camp.

That's when solar power takes over (except for one or two day trips).

Simple, but effective. And I can remove it from the vehicle for day to day use.

Cheers
Keithy

Has anyone considered the new narva voltage sensitive relay,will assure the start battery is up the voltage before charging the second,i agree with running the winch of the start battery as it can supply high amps and a deep cycle as a second for fridge,worse case you run start battery flat and jump of second battery

good to see a couple of Hunter Valley Landrover members on here,good work

Hi

The issue with simply connecting a second battery is that depending upon where the second battery is located, the voltage drop my be too great for the second battery to be charged. This is when you need a DC battery charger.

The setup needs to be different depending upon whether you want a second battery which can start the car, or simply as an auxiliary battery.

As far as electronic components failing, most of our vehicles are full of electronics, so that doesn't concern me in the slightest, provided they are properly specified and installed.

Steve

Quote:

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Originally Posted by Tombie

Robustness in the bush?! :lol:

On an Aux battery system?

Don't even consider the diodes, relays, rectifier pack, wiring connectors, fuses, fusible links, suspended lead plates, oil pressure switch, or other myriads of items that are just as vulnerable to failure which can render the vehicle Dead..

Or simple relays which can fuse in the latched position, draining both batteries...

Good to see Luddites are alive and well in the modern world :D :)

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Thanks very much.