If you want to turn your 4WD into an adventure-mobile, you’ll be needing this. It’s a dual battery system, and it’s one of the best modifications you can make.
Modify your 4WD in the middle of a lockdown? It’s not as crazy an idea as you might think. We’ve all been cooped up at home for months now, and we’re undoubtedly keen to partake in some good old-fashioned non-essential travel when bans are lifted.
And with non-essential domestic flights on the nose and international flights likely to remain banned, it’s never been so alluring to pack the family and/or friends into the family 4WD and do some exploring.
While you can’t take off right now, you can certainly start planning. Locations, itineraries, gear and modifications.
If you want to do some self-sufficient camping, arguably the most effective and rewarding of modifications is the ability to run things like fridges, power outlets and lights without a house plug in sight.
This Nissan Navara SL, which you’d remember from suspension modifications, along with the addition of barwork and some Victorian High Country exploring, is back under the knife. This time, it’s 12V electrics that we are looking at.
This is kind of work is beyond the scope of an average DIYer in the backyard. So, we’ve enlisted the help of some professionals: Walkers Auto Electrics in Brookvale, on Sydney’s Northern Beaches.
The idea is both well-known and well trodden: Adding an auxiliary 12V system to your vehicle, which is then able to power accessories without draining your engine’s main starter battery.
There are many ways to skin this cat, and it depends mostly on two things: a setup that suits your needs best, and suiting your vehicle. And of course, you’ll need to find something that suits your budget.
For this Navara, both under the bonnet and behind the rear seat isn’t suitable, so we looked at the tub for a solution. Walkers recommended a Trig Point slimline battery box, which it has used successfully in the past. It’s able to be securely mounted, and houses the Remco 106 amp/hour with plenty of room to spare. There’s enough room for up to 170 amp hours of slimline battery in fact, if we are ever keen to upgrade.
It’s a nicely made piece of kit, constructed mostly of powder-coated aluminium. Along with plenty of holes for mounting and wiring, there are also some zinc coated brackets for additional strength. This gets installed into the passenger side of the tub, up against the headboard. The Redarc BCDC 1225D bolts onto the side of the box, making installation quite easy.
That Redarc unit is the brains of the operation, keeping the auxiliary battery charged up from the vehicle, while also isolating the starter battery from going flat. While giving DC, it also handles solar power inputs and negates the long cable run between the alternator and charger. An Anderson plug is installed towards the back of the tray for attaching the 115-watt Redarc folding solar panel.
While the Navara is on the operating table, we opted to fit a Redarc 52mm dual voltage gauge to the interior to keep an eye on vitals. This gives you a clear readout on what’s going on with your volts and amps.
With all of this stuff bought and installed, one’s wallet will certainly be lighter. However, it’s an important box to tick for those who are keen to camp and get off the beaten track, or even just run a fridge in their car overnight without any worries about starting it up the next morning.
Product information list
Redarc BCDC 1225D DC-DC: $609
This charger is an incredibly popular choice for 4WD, caravan and camper trailer applications, giving 25 amps of charging capability in a tough and compact package. If you want faster charging, it can be had with 40- and 50-amp power outputs. It can handle AGM (absorbed glass matt), gel, lead acid, calcium and LiFePO4 lithium chemistries with specific charging profiles, and also does solar inputs through a Maximum Power Point Tracking (MPPT) solar regulator. It’s well made, with a sealed solid state that can withstand all manner of heat, dust and vibrations.
The BCDC can get hot in some under-bonnet installations, only operating faultlessly up to 55 degrees. This is why it’s recommended to be installed as far forward in an engine bay as possible, or elsewhere to avoid too much heat-soak. Our setup will likely see zero problems.
Redarc 115W folding solar blanket: $999
It’s expensive, but the quality is right at the pointy end. Going for a cool $1000, you’ve got a solid whack of solar power that folds into an easily storable size. It comes with a five-metre Anderson plug cable, which lets you run the blanket in the sun and your vehicle in the shade.
Naturally, this blanket-style panel doesn’t lend itself well to permanent installation. A cheaper, rigid mono-crystalline panel is the ticket for that. The real strength of this blanket is being able to be wedged away behind a seat or in a box, when storage space is at a premium.
Trig Point slimline battery box: $260
This is the main structure of the dual battery system, giving both the battery and the charger a home in the corner of the Navara’s tub. It’s nut-serted in place, and can be used in a variety of locations and applications. Trig Point tells us it’s made to suit a 170Ah Kickass AGM or Invicta 100Ah lithium battery, depending on your budget.
Redarc 52mm G52-VVA gauge: $196
While not needed to complete a dual battery install, the dual-voltage gauge is definitely in the ‘nice-to-have’ category. It gives you voltage of your starter and auxiliary batteries, and uses a hall effect sensor to read of how many amps are travelling into and out of your auxiliary battery. So that means you know exactly how much your accessories are draining, and you can also see how many amps your solar panel is drawing in from the sun.
A couple of hundred bucks for the gauge is cheap for a quality product in our opinion, but the majority of cost will likely come from the installation. Speaking of which...
Installation: $1200 (approx)
The team at Walkers Auto Electrics did a great job of installing all of the gear into the Navara, along with some additional power plugs in the tray to access the auxiliary grunt on offer. Your costs of installation will vary depending on your vehicle, existing modifications and how you want it all installed. A competent auto electrician will be able to provide an accurate quote. Walkers says the kind of work we did to the Navara would be around one day's work, at $1200, plus the consumables like cabling and sockets.