4WD Action editor Brendan Seymour has put together a 12v system that allows him to run twin fridges permanently – without ever having to turn them off.

“12v setups and products are constantly evolving, and my setup is no different. I’ve always had this idea in my head that the ultimate never-fail 12v system would allow me to run one or more 12v fridges permanently without ever turning them off. It’s a big ask, but using CTEK’s battery management products, that’s exactly what I’ve been able to do.”

Here’s how Brenno has been able to achieve that – and how you can too.

“I’m running a pair of twin 100Ah AGM batteries, wired in parallel,” Brenno explains. “This means that I’ve got 200Ah of battery capacity, which lets me stay at a particular campsite for a couple of days at a time without worrying about draining the battery bank. The twin batteries are mounted in my canopy, directly next to the main 80L fridge. I’ve also got an 11L centre-console fridge that stays on the whole time inside the cabin too. Combined, they use about 6A of power every hour on average.”

“The alternator in my Navara is like those found in many modern 4WDs,” Brenno continues. “It’s a ‘smart’ alternator, which doesn’t always put full charge into the auxiliary batteries. The solution is a DC/DC battery charger, which can handle varying input voltages while still producing proper charging voltages. In my case, I’m running the awesome CTEK D250SA DC/DC charger, paired with the CTEK SmartPass 120. These two bits of gear handle it all – they isolate the auxiliary batteries when I’m parked up at camp, and charge them when I’m driving. What I love is just how quickly they can charge the batteries up. Often the ute does lots of short trips, and the D250SA and the SmartPass 120 make sure I’m getting as much charge in as possible, every time I drive.”

“Sometimes I can go a week or more without driving the Navara,” Brenno continues. “The solution to keeping the batteries topped up and the fridges cold, is a 200W solar panel permanently mounted on the roof of the canopy. I ditched the regulator that came with the panel, and ran the solar straight into the D250SA’s inbuilt MPPT solar regulator. Often I’ll check what the batteries are doing during the day, and they’ll be sitting at 14.0V – with two fridges on, and a vehicle that hasn’t been started for days! The panel puts in about 14A when the sun’s shining. What’s even better is even when I’m driving, the D250SA continues to use that 14A as well as what is coming from the alternator to really crank the power in.”

“Sometimes I don’t get the opportunity to drive the ute for a week or more, and there’s not enough sun to properly keep the batteries topped up,” Brenno says. “When I realise that the batteries are running a little low, all I do is run a power cable out from the garage to the ute and connect my permanently-mounted CTEK M300 25A battery charger overnight. I can’t talk highly enough about this charger – it’s incredible. You can select whether you’re charging a regular or an AGM battery bank, and it has a recondition charge that has, to this day, saved four separate batteries from going to the scrap pile. They were batteries that had been flattened and would not take any other sort of charge, but are still in service now thanks to the M300.”

“My ute actually has twin crank batteries,” Brenno explains. “While there isn’t any load on them when the ute’s sitting around, they naturally go a little flat after not receiving charge for a while. That’s where I use the clever new CTEK Time To Go battery charger. I just connect it to the crank batteries and let it do its thing. It has this beaut little LED display that shows how the charging is going, when you can try to start the vehicle and when the battery is fully charged. The Time To Go actually gets used on the missus’ car, both 4WDs, the motorbikes and even the little trailerboat – it definitely earns its keep!”

“I’m definitely a technology fan,” Brenno says. “That’s why I run a pair of the awesome CTEK Battery Sense Bluetooth battery monitors in the ute. I’ve got one connected to the crank battery bank, and one connected to the auxiliary battery bank. They constantly monitor the batteries and let me know if I need to charge them. Definitely the perfect way to round out the ultimate 12v system!”

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