SNEAK PEAK: National Luna’s new 40A DC-DC power pack

In a recent technical column, we described the pros and cons of using a 40A DC-DC charger versus a 25A unit.

You can read that blog piece here, otherwise, here’s a summarised version below…


Although a 40A DC-DC charger appears to be the ultimate dual-battery solution, the benefit of using a 40A charger is mostly seen during the ‘bulk’ stage of the recharge cycle.

Once you include the ‘absorption’ stage in the overall process, the total recharge time is similar for both a 25A and 40A DC-DC system.

This is because the total recharge time is determined by the battery’s technology, and not by the charger itself. Simply put: The battery is the limiting factor, not the DC-DC charger.

However, because a 40A DC-DC will reduce the bulk charging time of your auxiliary battery, the real benefits are realized when you need to quickly replace used energy within the first 3-hours of driving.

If you’re using a lithium-based battery, you could probably knock that time down to 2-hours!


With the above points in mind, National Luna is due to launch a brand new product: A 40A DC-DC power pack. It will be the first of its kind on the market, and further expands our range of industry-leading dual-battery solutions.

Previously, in 2019, we launched a 25A DC-DC power pack, which the market unofficially branded: ‘The Green Box’. Due to the success of that product worldwide, and calls for a 40A version, we’ve now developed a far punchier unit, one that incorporates our built-in 40A DC-DC charger.

So why would you want a 40A DC-DC power pack instead of a 25A unit? Well, the higher amperage is beneficial when…

  • You want a much faster charging time within the first 3-hours of driving – which is arguably where it matters most.
  • You have a large capacity battery.
  • You want the extra solar capabilities.
  • You’re powering a load (a fridge or another appliance) at the same time as charging the battery.
  • You have an alternative power source such as a wind generator or AC-DC power supply.

Other features of the 40A National Luna Green Box include:

  • Plug ’n play solar input
  • Lithium-battery compatibility
  • Built-in battery voltage meter
  • Dedicated charger port
  • True 40A output current
  • 5-stage intelligent charge algorithm
  • AGM, Gel, Wet, Calcium, Lithium support
  • Alternator input up to 32V
  • 40A, 600W MPPT solar regulator
  • Supports solar panels up to 42V
  • Separate auxiliary DC input up to 32V
  • Smart-alternator compatible
  • Battery temperature compensation for safe charging
  • Short-circuit protected
  • Reverse-polarity protected
  • Over-voltage protected
  • Over-temperature protected

More DC-DC products from National Luna

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