Every caravanner eventually hits the same wall. The camp fridge needs to stay cold for three or four days off-grid, and the starter battery was never built for the job. From there, the choice splits two ways. You can drop a portable power station in the van and plug straight in, or wire a second battery into the caravan 12V system and build a dual-battery setup. Both work. They just suit very different travellers, and the wrong pick can cost you hundreds of dollars or a fridge full of spoiled food. Retailers such as Outbax sell both systems, so this guide plays no favourites. Here is how the two options compare on cost, installation, portability, and real fridge runtime in Australian conditions.
What a Portable Power Station Gives You
A portable power station is a sealed unit that packages a lithium battery, an inverter, a charge controller, and a bank of outlets into one carry-anywhere box. There is nothing to install and no auto electrical work involved. You charge it at home, lift it into the caravan, and plug your gear in.
No Installation Cost, Ever
This is the headline advantage. A wired dual battery system typically needs an auto electrician, and labour alone can run several hundred dollars. A power station has zero installation cost. It also moves with you. Change tow vehicles, upgrade the van, or lend it to a mate for a weekend, and the whole setup comes along without touching a single wire.
Every Outlet You Need in One Box
Because the inverter is built in, a power station gives you 240V AC sockets, USB ports, and 12V outputs from day one. A mid-sized unit such as the VoltX Topband V1200 from Outbax stores 1,152 watt-hours and delivers 1,200 watts of output, enough to run a camp fridge, lights, laptops, and a coffee grinder at the same time. Weekenders with lighter loads can start with the VoltX E600, a 7kg unit that handles phones, lighting, and a small portable fridge for camping without breaking $500.
Here’s what one of our customers said about the VoltX E600 Power Station:
"Love the ease of use, great being able to see how much wattage is in use. Very versatile and has all the ports I need and more. Enough storage to run my fridge at night while camping. Highly recommend!"
Solar Input Keeps It Topped Up
Most quality stations accept solar input through a built-in MPPT controller. Pair one with a folding panel, and you can hold a fridge indefinitely in decent sun, which matters on longer free camping stays where there is no powered site in sight.
What a Built-In Second Battery Gives You Instead
The traditional route is a deep-cycle lithium battery mounted in a battery box, under a seat, or in a chassis locker, wired directly into the caravan 12V system. Your existing lights, water pump, and fridge circuit all draw from it as if the caravan came that way from the factory.
More Amp-Hours Per Dollar
A raw LiFePO4 battery is the cheapest way to buy storage. A 200Ah unit such as the VoltX 12V 200Ah Pro LiFePO4 Battery holds 2,560 watt-hours, more than double the capacity of most $1,000 power stations, usually for less money. You are not paying for an inverter, a screen or a plastic shell. If maximum capacity per dollar is the goal, the second battery wins comfortably.
Charging Happens Automatically While You Drive
Add a DC-DC charger and the battery charges from the vehicle alternator every time the engine runs. On long touring legs between stops, which is most of Australian caravanning, the system tops itself up without you thinking about it. That set-and-forget quality is why serious tourers still favour dual battery systems.
The Trade-Off Is the Install
Wiring, fusing, a charger, and professional labour add real cost and lock the battery into one van. Budget roughly $200 to $400 for a quality DC-DC charger and several hundred dollars more for installation unless you are confident doing compliant 12V work yourself.
Head-to-Head: Cost, Installation, and Portability
Here is the short version of how the two systems stack up.
| Feature | Portable power station | Built-in second battery |
|---|---|---|
| Installation | None, plug-and-play | Wiring plus a DC-DC charger |
| Portability | High, carry it anywhere | Fixed inside the caravan |
| Cost per watt-hour | Higher, inverter included | Lower, battery only |
| Outlets | 240V AC, USB and 12V built-in | 12V native, inverter optional |
| Charging on the road | Car socket or solar input | Automatic from the alternator |
| Space in the van | Takes up living space | Hidden in a locker or battery box |
On total cost of ownership over five years, the math tends to favour the second battery for people who tour often. The install cost is paid once, LiFePO4 cells routinely last 2,000 to 4,000 charge cycles, and the cost per usable watt-hour lands well below any all-in-one unit. The power station makes up for it with flexibility. It doubles as home blackout backup, needs no professional labour, and holds resale value because it is not bolted to your van.
How Long Will Each Run Your Camp Fridge?
The camp fridge is the load that decides this decision, so it is worth doing the numbers properly.
Work Out the Real Daily Draw
A typical 40L to 50L compressor camp fridge draws around 50 watts while the compressor runs. In Australian summer conditions, the compressor cycles on roughly 40 per cent of the time, which works out to near 480 watt-hours per day. Hotter weather, frequent lid opening, and a full freezer load push that higher.
Side-by-Side Runtime
A 1,152 watt-hour station such as the VoltX Topband V1200 delivers roughly 980 usable watt-hours after inverter and conversion losses, which is about two days of fridge runtime with a little left for phones and lights. A 200Ah second battery holds 2,560 watt-hours, and because LiFePO4 tolerates deep discharge, you can comfortably use around 2,000 of them. That is four days or more running the same fridge through the caravan 12V system, with no inverter loss on a 12V fridge.
Here’s what one of our customers said about the VoltX Topband Power Station:
"Although I bought this for camping, it's come in handy more than once for providing power during power outages at home. Several hours of my laptop, NTD and router plugged in and only used 15% of the battery. Easy to use and charge, do recommend."
Solar Changes the Equation for Both
Add 150 to 200 watts of panels and either system can run a camp fridge indefinitely in reasonable sun. Travellers powering other bigger loads, like induction cooktops or an air conditioner in short bursts, should look at higher output units such as the VoltX M2000 Portable Power Station, which pairs 1,536 watt-hours with 2,000 watts of output.
Which Setup Should You Choose?
Choose a portable power station if you value flexibility above everything. It suits weekend and school holiday travellers, anyone who changes vehicles, renters who cannot modify a van, and households that want blackout backup at home between trips. A compact unit like the VoltX E800 Power Station covers all of that in a single 518 watt-hour package.
Choose a second battery if you tour hard and often. Long laps, extended free camping, and permanent caravan power setups reward the lower cost per amp-hour, the hidden mounting, and the automatic alternator charging while driving.
Plenty of experienced travellers end up running both. A wired 200Ah battery carries the caravan 12V system, and a small station handles power away from the van at the camp table, the beach, or the footy. If you are unsure which way to jump, the Outbax team in Sydney can size either system against your fridge and travel style before you spend a dollar.
The Bottom Line
There is no universally correct answer, only the right match for how you travel. Zero installation and going-anywhere flexibility points to a portable power station. Maximum capacity per dollar and seamless integration point to a second battery and a DC-to-DC charger. Price both against your actual fridge draw, not the biggest number on the box, and you will land on the right system for the first time. You can compare current portable power stations and caravan batteries side by side at Outbax.
