Most RVers would be familiar with 12V electrical systems, but with the growing shift towards gasless caravans and power-hungry RVs, 48V is gaining traction. But what is it, do you need it and are there any drawbacks?
First of all, let’s explain the difference between 12V and 48V. Both are portable, battery-stored electrical systems used to power lights, appliances and electronics when you are off-grid and unable to connect to mains (240V) power. The voltage is a measure of the battery’s capacity to store and discharge energy. In RVs, 12V traditionally powers the lights and low-draw appliances such as USB charge points and compressor fridges. Both 12V and 48V power systems can support larger, more electricity-intensive appliances, such as a household kettle, when the power is converted to 240V through an inverter.
The main difference between 12V and 48V batteries is their load capability. 48V systems have greater capacity to capture, store and distribute power than 12V because they are more energy dense. Put simply, 48V provides more electricity (watts) using the same amount of electrical current (amps) as 12V because it’s more powerful and efficient. Confused? Let me explain with a common garden hose analogy. Imagine the volts are the water pressure, the amps are the water flow rate, and the watts are the force of water sprayed from the end the hose. Because 48V has four times the power of 12V, it can produce quadruple the amount of force (watts) from the same electrical current.
48V x 10 amps = 480 watts
12V x 10 amps = 120 watts
The more energy hungry the appliance, the greater wattage it draws. For example, your average toaster draws 1000 watts of power, while an induction cooktop can draw up to 2000 watts. The more watts an electrical system delivers, the larger and greater the appliances you can run simultaneously.
The biggest benefit of switching to 48V is the ability to draw, store and dispense more power. This means you can live off grid more comfortably and for longer without sacrificing any mod cons. Morning cappuccino, anyone? This is increasingly more important as today’s modern caravans and motorhomes have hefty power demands. Induction cooktops, coffee machines, air fryers and even Thermomixers have become commonplace in vans. And if you want to use these appliances for an extended period, and while doing a load of washing or running the air-conditioner, you need a large and sophisticated energy system. Of course, using power-hungry appliances requires an inverter to convert the electricity to 240V. With a 48V system, this is a much smaller jump than stepping up the voltage from 12V. As a result, the conversion is more efficient, with less energy loss, so you get much more bang for your buck.
Surely a higher-capacity, more powerful battery means a heavier and bigger unit in you RV? No, actually. Another huge selling point of 48V lithium batteries is they are more compact and lighter than 12V lithium batteries. This is because they are more energy dense and efficient – providing more power for less space. That means extra storage and payload in your RV.
48V power systems also use thinner cabling than an equivalent 12V system because the individual wire strands can conduct more electricity at higher voltage. With 12V, you need more strands bundled into the cable to carry the equivalent power. With fewer wiring strands, cabling is cheaper, neater and safer. There is also less energy loss and the wiring is less likely to overheat and become a fire hazard.
With a 48V battery bank, fed by a large complement of solar (upwards of 800W) and a powerful inverter, you can be self-sufficient for power. For many RVs, this means going all-electric with no reliance on gas. Not only does this save yet more space and weight, but it also eliminates the expense and inconvenience of refilling or exchanging gas bottles. You also no longer need vents inside your RV, reducing dust ingress.
Squirrel away those savings you make in LPG refills because you’re going to need the extra cash to pay off your 48V system. The technology is still quite new in RV circles, and this is reflected in the cost. While the price depends on the size of your battery bank, invertor and solar system, expect to pay significantly more than a 12V system, especially given the extra solar required to feed the batteries at a higher voltage.
Power systems running on 48V need high-voltage solar input to adequately charge. For this reason, rooftop panels are arranged in a solar array. This means they are effectively wired together and their power input is fed collectively into a solar controller for maximum charge. The downside of this system is partial shade on one panel impacts the entire output of the solar panel string. Consequently, you will need to be strategic about where you park your RV for optimal sun exposure.
If you’ve done away with gas bottles to make the leap to all-electric, you might want to consider a power redundancy, like diesel, just in case. Having a diesel heater and hot water system will take some of the load off your batteries. Likewise, a diesel generator is a good back-up when the sun isn’t shining.
While it’s okay for an amateur sparky to tinker with the wiring on a 12V fan, it’s is not safe to install a 48V system, especially when wiring large solar panel loads. Use a licensed electrician, experienced in RV systems, who knows what they’re doing. It’s extra cost but peace of mind.
So is 48V worth the investment? It depends on your power needs and lifestyle choices. If you spend large amounts of time off-grid, prefer all-electric over gas and have a penchant for Thermomix curries eaten in air-conditioned comfort with a latte chaser, 48V could be for you.
