The decision to install a dual-battery system is often motivated by the need to run a 12V camping fridge. But does the purchase of a portable fridge automatically necessitate the need for a dual-battery system?


Or, can you get away with running your fridge on a standalone auxiliary battery without a split-charging isolator?


Of course, the answer to that question depends on several factors, namely…


  • Do you often camp off-grid?
  • How many days do you typically camp?
  • How efficient is your fridge?
  • Do you have a solar panel?



National Luna Black battery box
The National Luna Black Box is a customisable auxiliary battery system that has no built-in charger and/or isolator. It’s perfect for weekend campers who need to power their portable fridge and 12V lights for no more than a day or two.



Your camping habits play a big role in your decision to install a dual-battery system. Because all National Luna fridges run on both 12Vdc and 220Vac power, if you predominantly camp in locations where mains power is available, then a split-charging system is not a necessity.


However, if your camping trips typically involve multiple campsites, game drives and exploratory routes, then you will definitely benefit from installing a dual-battery system.


National Luna Grey Box with solenoid dual battery system
The National Luna Grey Box is our oldest and most popular power-management solution. The Grey Box features a built-in dual-battery system and intelligent solenoid that isolates your auxiliary battery from your vehicle’s cranking battery while the engine is off, but then allows the second battery to recharge from the alternator when the engine is running.



What’s more, if you’re a weekend camper who seldom spends more than a long weekend away, you could potentially get away with an auxiliary battery without the need for a dual-battery charging system and/or isolator.


Once again, this depends on several factors, including: The capacity of the auxiliary battery, the condition of the battery, the operating temperature of the fridge, how often you open and close the unit, and, the efficiency of the fridge itself.


That said, it’s not always necessary to keep your fridge set at ultra-low temperatures. For example: readjusting your fridge’s temperature setting in the evening (when the ambient conditions are cooler) will significantly save battery power.


Taller battery box, national Luna blue box
Much like the Black Box, the National Luna Blue Box is also a customisable auxiliary battery system with no built-in charger and/or isolator. The difference between the two products is that the Blue Box is slightly taller than the Black Box and can accommodate larger, higher capacity batteries.




Contrary to popular belief, the efficiency of a 12V camping fridge has less to do with the compressor’s performance and/or technology, and more to do with the quality and thickness of the insulation.


The thicker the insulation, the longer the fridge will stay cool, the less often the compressor will cycle on, and therefore, the less battery energy the fridge will draw.


With this in mind, any attempt to power a 12V fridge on an auxiliary battery – without installing a split-charging system – will definitely require a fridge that boasts excellent insulation and efficiency.



While solar power is certainly an effective way to power a camping fridge and reduce the need for more battery capacity, solar energy is highly weather dependent and not a guaranteed source of energy.


However, in saying that, a number of premium DC-DC dual-battery systems are equipped with a built-in solar regulator. So aside from recharging your dual-battery via the vehicle’s alternator, you also have the option of keeping the battery topped up with a suitably sized solar panel.



National Luna Green Box with DC-DC charger
The National Luna Green Box is our flagship portable power solution that features customisable power ports, a 25A DC-DC charger and isolator, MPPT solar regulator, and the ability to recharge lithium-ion batteries, too!


But before you commit to any particular set-up, you’ll definitely want to read this blog piece on, “Which dual-battery system is best: Solenoid or DC-DC?”


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