When it comes to portable refrigerators, there are plenty of models to choose from. We recently profiled the impact that ARB fridges can have on vehicle battery life, so we'll turn our attention to another popular portable refrigerator manufacturer, National Luna.
Here's a breakdown of the kind of battery life you can expect while operating a National Luna fridge, along with some information about choosing the best system to power your fridge.
First, Let's Talk About Batteries
Measuring Battery Capacity
An amp hour (Ah) is the measure of hours a battery can generate one amp of current at 12 volts before the battery dies. This serves as a way to compare one battery with another.
To establish the amount of energy a vehicle battery is capable of storing, the Ah rating should be determined. The greater the amount of amp hours a battery is capable of storing equals a longer amount of time your portable fridge can be plugged into your vehicle without draining the battery.
Deep-Cycle vs. Starter Batteries
Deep cycle and starter batteries are in entirely different classifications, since each is designed to accomplish different tasks. Deep cycle batteries produce low volumes of continuous power. Starter batteries, on the other hand, generate substantial power for a limited amount of time.
And while starter batteries are commonly used because they are inexpensive and "good enough" for most vehicles, certain situations (like operating a portable fridge for hours at a time) call for deep-cycle batteries.
Deep-cycle batteries were created specifically for storing energy. This type of battery can be discharged up to 50% without experiencing a loss of battery life, and some manage to discharge 75% without loss. Deep-cycle batteries are ideal for operating your National Luna fridge for hours (or even days) at a time.
Powering Your National Luna Fridge From Your Vehicle
If you're going to run your fridge off your vehicle's electrical system, you absolutely want to ensure that the fridge doesn't kill your vehicle's main starter battery.
One way to protect your starter battery is to install a dual battery system. While this is a popular option, it's not at all the best option. Dual battery systems are expensive, complicated to install, and restrict you to using your portable fridge with your vehicle.
Instead, we suggest powering your fridge from a separate battery source such as the ArkPak. This way, you don't have to worry about draining your vehicle starter battery (the two aren't connected), and you can use your fridge anywhere you like, as the fridge and the Arkpak can be carried to your boat, a tailgating party, whatever.
National Luna Fridge/Freezers and Battery Life
Last but not least, here's a quick chart breaking down battery life by National Luna refrigerator model. Our current draw estimates were taken from the National Luna website - they are the average of the average current draw range stated by National Luna. Be sure to compare these ranges to the ARB Fridge/Freezer to see how much more current the National Luna Fridge/Freezer draws for a similar-sized unit.
|National Luna Fridge/Freezer Size||Current Draw (Amps/Hour)||60ah Deep-Cycle Battery||80ah Deep-Cycle Battery||100ah Deep-Cycle Battery|
|50 liter “weekender”||2.1||20||27||33|
|90 liter twin compartment||1.5||28||37||47|
|72 liter double door||1.9||22||29||37|
|110 liter double door||1.9||22||29||37|
NOTE: These times assume you discharge the deep-cycle battery 70% (30% of total charge remaining), and they assume that your battery has 100% of its' listed capacity. Therefore, you should view these times as theoretical maximums and discount them a few hours to make sure you don't ruin your battery by over-discharging it.
As you can see, the current draw requirements for National Luna fridges don't differ much from one model to the next, at least based on the numbers given on the company's website. While an ARB fridge may offer greater battery life than a similarly sized National Luna fridge (again, see this article for ARB fridge and battery life estimates), National Luna offers larger fridges AND features like dual compartments and/or dual doors.
To be clear, Ark has no opinion on which fridge/freezer is "better," and we want to be careful to point out that these battery life estimates are based on estimated current draw. Your results may differ.
All we suggest is that you use the ArkPak to power your fridge (whatever brand it is) rather than a dedicated dual battery system. The ArkPak can accept a 130ah battery and is both powerful and portable. It can be charged from a solar panel, etc. A dual battery system that's mounted to your vehicle isn't any of these things, at least not typically.