The ultimate power pack for a zombie apocalypse

In light of people mass-buying bog roll, I thought I’d share what I believe to be the ultimate survival (power) pack for an apocalypse. To clarifying, I’m not a toilet-roll hoarder, nor do I have canned food buried in my yard; however, like most campers, I like the idea of being self sufficient and prepared for outdoor life… or alternately, life on the run in a world of zombies.

But before we get to that, let’s explore what an end-of-days power-pack solution should look like…

  • First and foremost, it should be portable. Something you can use in your house in the event of a black out, but if needs be, you can quickly throw it in your vehicle and hit the road.
  • It would have to accommodate a wide range of battery types, including Calcium, AGM, GEL and Lithium-Ion.
  • You need to be able to recharge the power pack in your house, as well as in your vehicle.
  • For those occasions when you’re not driving, you definitely want to be able to recharge the battery with a solar panel, without fussing over wires and connections.
  • Such a power pack must come equipped with a multitude of output power points.

On that note, I give you the National Luna 25A DC-DC Auxiliary Battery Box (Aka: the Green Box), the only backup power solution you’ll need for the zombie apocalypse. Here’s what it does…


National Luna has several power-pack options in their product line, one being a Grey Box, the other a Black Box, and now, the most recently launched Green Box. Their Grey Box solution has been around for many years and is sold in dozens of countries worldwide. That said, the idea behind all of National Luna’s power-pack solutions lies in three concepts: portability, durability, and usability.


As you probably know, how a battery is recharged is vital to its performance and safety. For example, you can’t recharge a Lithium-Ion battery the same way that you would recharge a lead-acid battery. With this in mind, you want a power pack that can accommodate and recharge a host of battery options.

The National Luna Green Box can be connected straight to your vehicle’s main starter battery / alternator, and, depending on what setting you opt for, it will adapt its charging profile to best suit the battery you’ve selected – whether that be a Calcium, AGM, GEL, EV Traction and/or Lithium-Ion.


As mentioned before, a critical aspect of any power-pack solution lies in its ability to recharge from your vehicle’s alternator while you’re driving. This is otherwise known as a dual-battery system, where you essentially equip your vehicle, caravan or camper with a second battery that automatically recharges at the same time as your vehicle’s main starter battery.

Once you turn the vehicle off, an isolator switch (within the dual-battery system) automatically disconnects the two batteries so that you can power a 12V fridge or camping light on the auxiliary battery without running the risk of draining your vehicle’s main starter battery.

Most dual-battery systems are simple in design and function, but as newer vehicles on the market make use of variable voltage alternators, the demand for a more sophisticated dual-battery system has arisen. That said, a number of manufacturers now offer DC to DC dual-battery systems that are able to boost the alternator’s low voltage output in order to fully recharge the auxiliary battery.

Most DC to DC dual-battery systems are permanently wired into your vehicle (such as the one featured above), but National Luna took the concept one step further and built their DC to DC system into a portable option. As far as I know, no other company has done the same.


If you’re going to camp off grid for more than 3 days (without driving your vehicle) you’re bound to need a solar panel in order to keep your power pack topped up.

These days, solar panels are up 66% cheaper than they were just 4 years ago, and they’re more efficient, too. The cost to buy a high-quality solar panel is surprisingly affordable. However, when you factor in the cost of a high-quality MPPT solar charger on top of the panel price, the costs do add up.

A solar charger is what converts solar energy into usable battery energy. How efficiently (and effectively) it does this is determined by the quality of the solar charger, and whether it’s a PWM charger (the cheap type), or a MPPT charger (the expensive type).

Fortunately, the National Luna Green Box is equipped with a super high-quality MPPT solar charger that has a maximum current and power rating of 25A and 375W respectively. The Green Box is also fitted with a heavy-duty Brad Harrison plug that connects directly to the MPPT charger. This means, connecting your solar panel to the power pack is literally as easy as plugging it in. The built-in MPPT will do the rest in terms of converting free solar energy into usable battery energy. Toss in a high-quality inverter, and you have yourself a complete 220V battery pack that can run your TV, wifi and a few LED lights at home, too.



The Green Box has no shortage of output power points, including one Hella 12V socket, two auxiliary 12V sockets, four 3A USB ports, and two heavy-duty 50A in/out connectors. With such a diverse range of plug points, you can power or recharge everything from a cellphone or tablet, to a GPS unit and/or even a large-sized camping fridge.

But the best feature of all is that you can also swop any of the above-listed power points for an alternative connection. In other words, if you want two Hella plug points instead of one, you can swop the 12V Auxiliary port for another Hella socket, or, any other National Luna widget.   

You’ll be pleased to hear that each available plug point has its own safety fuse. So if one fuse blows, it won’t affect the operation of the other plug points.


As I’ve just mentioned, there are a number of widgets (sold separately) that can be used within the Green Box, as well as several optional extras – the most useful of which being the Remote Monitor.

Although the Remote Monitor isn’t pivotal to the Green Box’s function, it is an invaluable piece of kit in terms of information – particularly where solar power is concerned. Aside from displaying the battery’s current state of charge, capacity and battery type, the Remote Monitor also tells you how much energy your solar panel is producing, how much energy your vehicle’s alternator is producing, as well as the battery’s operating temperature. This last point may not sound that important, but battery temperature is critical to the battery’s lifespan, as well as how quickly it will accept a charge.

The Remote Monitor is an invaluable extra in terms of displaying battery information.

The Green Box has a dedicated port on its front panel where the monitor plugs in, and you can mount the monitor’s high-contrast display on the power pack itself, or in the case of a vehicle setup, on your dashboard where you can keep a close eye on it.

The National Luna 5A Intelligent Battery Charger is another vital accessory for your Green Box. Again, the power pack is equipped with a quick-connect port that’s designed specifically for National Luna’s 5A charger, but you can also connect any other brand of charger to one of the power pack’s input ports.

A 220V battery charger is critical for maintaining battery life, however, a solar panel will also serve the same function.

In the case of the National Luna Intelligent Battery Charger, the 5A unit has a boost function, as well as a maintenance function. Meaning, it can restore a deeply discharged battery if needs be, but you can also leave the charger permanently connected to the Green Box without having to worry about overcharging the battery or boiling its electrolyte.

It that sense, with an Intelligent Battery Charger connected, your Green Box can also function as a form of UPS (Uninterrupted Power Supply). However, this last application will depend on what it is you’re trying to power and how many amps it’s drawing.


So, in short, the National Luna Green Box is a portable power-pack solution that…

  • You can use in your vehicle, as well as in your house
  • Can be recharged via solar power, 220V power, or 12V vehicle power (alternator)
  • Can accommodate a wide range of battery types, including Calcium, AGM, GEL and Lithium-Ion
  • Can power your 12V camping fridge
  • Boasts a number of input/output power points
  • Is made from an impact resistant and highly durable material 
  • Is 100% safety compliant with fused power ports, an overload trip switch, and reverse polarity protection  
  • Features a customisable faceplate
  • Offers a range of optional accessories, including a digital monitor and purposefully-made battery charger



1) How easy is it to install the Green Box into my vehicle?

Super easy, all you need to do is run the supplied 16-gauge cable from your main battery’s terminals, to the Green Box’s location, and include a 40A fuse that’s supplied with the kit.

2) Can I have the Green Box connected to my vehicle’s alternator and the solar panel at the same time?

Yes you can. The Green Box will give preference to the alternator’s power input, but as soon as you turn the vehicle off, it will immediately start using solar energy.

3) What’s the biggest battery I can fit into my Green Box?

This will largely depend on what battery technology you opt for, but in some cases, you may be able to get a 140A/h AGM battery to fit. Typically though, most 110Ah batteries are an easy fit.

4) If I want to use the Green Box in my home for load shedding / power outages, what size inverter should I use?

The inverter size will depend on what it is you’re trying to power, but if it’s just for your TV, wifi and one or two LED lights, a 500VA Pure Sine Wave inverter will do the job. However, keep in mind that any appliance that generates heat will require much more battery- and inverter power, so avoid trying to power your kettle, toaster or hair dryer.

5) What size solar panel can I connect to my Green Box?

The unit’s built-in MPPT is rated at a maximum input voltage of 42V, and a maximum battery charge output of 25A and 375W. However, for most camping applications, a 135W panel is often the most convenient in terms of panel size, packing and portability. 

By Grant Spolander

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