A practical guide to combined output, the parallel kit, and choosing a pair that runs a caravan air conditioner without waking the campsite. Written for Australian campers and caravanners.
Running two portable generators in parallel gives you close to double the power at your campsite, while each unit stays light enough to lift on its own and quiet enough to run through the evening. Two smaller inverter generators, linked with the right parallel kit, combine their output through a single outlet so you can run a caravan air conditioner or a run of high-draw appliances that one compact unit could not manage alone.
This guide explains what a parallel setup actually gives you at camp, how the connection works, and how to size a pair so it does the job. It draws on the range of inverter generators Outbax stocks for Australian campers, and it flags the safety checks that matter before you buy.
» MORE: How to choose a portable generator for camping
What Does Running Two Generators in Parallel Give You at Camp?
Running two generators in parallel means linking two compatible inverter generators so their combined output feeds one outlet. For campers, the payoff is practical rather than technical. Here is what the setup delivers.
- Double the usable power. Two 2kW units give you a combined output near 4kW at peak and roughly 3.4kW of steady running watts. That is enough to start and hold a caravan air conditioner, which a single 2kW generator would struggle to manage on its own.
- Weight you can actually carry. A single large generator that matches the same output can weigh 45kg or more. Two compact inverter units in the 18kg to 20kg range, such as the Gentrax GT2000 Inverter Generator at around 18.5kg, are far easier to lift into a ute or caravan boot one at a time.
Here’s what one of our customers said about the GT2000 Inverter Generator:
“Best thing l have done buying from you and the advice was good. Does all l want. Best thing it’s quite. l would recommend anyone to buy from you.”
- Quieter evenings. Small inverter generators run at roughly 58 to 62 decibels at seven metres, close to normal conversation. That keeps you on side with neighbours at a caravan park and is far kinder than an open frame generator sitting above 65 decibels.
- A built-in backup. If one unit needs servicing or runs low on fuel, you still have a working generator. A single large machine gives you no such fallback.
- Fuel you only burn when you need it. On a quiet day, you can run one generator for lights, charging, and the fridge, then bring the second online only when the air conditioner goes on. That flexibility is hard to match with one big engine.
Gentrax GTX6600 Inverter Generator
How Does a Parallel Generator Setup Actually Work?
A parallel kit is the approved cable system that links two inverter generators and combines their current into one heavy outlet, usually a 30 amp or 50 amp socket on the kit itself. You then plug your caravan lead or appliance into that single outlet rather than into either generator.
This works cleanly because of how inverter generators build their power. Each unit produces raw power, converts it to DC, then rebuilds a stable, pure-sine-wave AC output under digital control. Because that final output is managed electronically, two parallel-capable units can synchronise their voltage, frequency and phase through dedicated parallel ports.
Synchronisation is what lets the two feeds share the load safely instead of fighting each other.
Two rules matter here. First, pair only units the manufacturer lists as parallel-capable, ideally two identical generators of the same model, wattage, and voltage. Not every inverter generator has parallel ports, so check the manual before you assume a pair will link. Second, use the exact parallel kit specified for those models. Never join two generators through their standard sockets, homemade cords, or splitter adapters. That is unsafe and can void your warranty.
The combined output you can actually draw is capped by the lowest link in the chain: the generators, the kit, its outlet, and the breaker. A pair rated for 4kW won't deliver 4kW if the kit outlet or your 15-amp caravan lead limits it first
Gentrax GTX3500 Inverter Generator
The Power Maths: Watts, Surge, and Your Caravan Air Conditioner
Getting a parallel pair right starts with two numbers on every appliance: running watts and starting surge.
Running watts are what a device draws once it is running. Starting surge, sometimes called surge watts, is the short spike an appliance pulls the instant a motor or compressor kicks in. Anything with a motor—a fridge, a pump or an air conditioner—surges well above its running figure for a second or two.
A caravan air conditioner is the appliance that usually pushes campers toward a parallel setup. A 13,500 BTU unit typically draws around 1,300 to 1,500 running watts, but can spike to roughly 2,800 to 3,000 watts or more the instant the compressor starts. A 15,000 BTU unit sits higher again. A single 2kW generator cannot cover that surge, which is why two units in parallel become the sensible answer.
When you size a pair, read the rated output, not just the headline maximum. Maximum output is a brief peak the generator can hit; rated output is what it sustains. Two Gentrax GT2000 units give a combined maximum near 4kW and a rated output around 3.4kW, which can comfortably start and run a 13,500 BTU air conditioner, with headroom for lights and a fridge.
A useful habit borrowed from the Outbax buying advice is to add about 30 per cent to your total. If your appliances add up to 2,600 running watts, aim for a combined rated output near 3,400 watts so the surge never stalls the pair.
Gentrax GS2-7500IE 7kW Portable Inverter Generator
Choosing a Gentrax Pairing for a Parallel Setup
The right pair depends on what you plan to run. Match the combined output to your load, then confirm both units are parallel capable and pair them with the correct kit.
For a basic powered campsite: If you only need lights, device charging, a portable fridge and the odd small appliance, a pair of lightweight units is plenty. The Outbax GT800 Inverter Generator at 0.8kW or the Gentrax GT1200 Inverter Generator at 1.2kW are compact and easy to carry, and two of either give you a modest combined output without the bulk of a larger machine.
Here’s what one of our customers said about the GT800:
“I have had this little fella for several years now, and its performance has been faultless. I live in FNQ and my power supply is appalling. For example, the genny has been running for about 25 hours in the last week. I kid you not. So it has taken a lot of hours. I give it regular oil changes and it starts the first pull every time. It is all that I need to run the essentials - lights, computer, fridge (inverter motor), and occasionally, the washing machine. This is starting to sound like a paid ad., but it's not. At this price, it is an absolute bargain.”
For running a caravan air conditioner: This is where 2kW units earn their place. A pair of Gentrax GT2000 Inverter Generators, or the slightly stronger Gentrax GT2200 Pro Inverter Generator at 2kW rated each, delivers the combined running watts and starting surge a 13,500 BTU air conditioner needs, while each unit stays around the 18kg to 20kg mark. Pricing sits around $649 per unit, so a pair is a real investment, but you gain portability, quiet running and a backup a single machine cannot offer.
Before you buy: Confirm the specific model supports parallel operation and that a matching Gentrax parallel kit is available. Parallel capability is not universal across every inverter generator, so this one check saves disappointment. The Outbax team can point you to the right pairing and kit for your setup.
» MORE: Compare the full inverter generator range
Two Small Generators or a One Big One?
A parallel pair is not automatically the better choice. It comes down to how you camp.
Two small units win when portability, noise, and flexibility matter most. You can carry each generator separately, run one to save fuel, and keep a spare if one fails. For caravanners who move often and value quiet, a twin setup is usually worth the extra outlay.
One larger generator wins when simplicity and cost come first. A single Gentrax GTX3500 Inverter Generator at 3.5kW, or the Outbax GT3500 Inverter Generator, delivers strong output from one machine, with no kit to buy and nothing to synchronise. If you rarely move it far and do not mind the weight, one unit can be cheaper and simpler than two.
There is also a middle path. Buy one capable inverter generator now, then add a second identical unit and a parallel kit later when your power needs grow. Staging the spend this way spreads the cost and keeps your options open.
VoltX VX6600 2-Wire Inverter Generator
Staying Safe When You Run Generators at Camp
A parallel setup adds a second engine, so the standard generator safety rules matter twice over.
- Ventilation comes first. Generators give off carbon monoxide, a gas you cannot see or smell. Never run either unit inside an annexe, tent, caravan or enclosed space. Keep both engines outside and at least five to seven metres from windows, doors, and vents.
- Keep them dry. Do not run a generator in the rain or wet conditions. If weather closes in, use a purpose-built generator cover that shelters the unit without blocking airflow.
- Mind the connection. Only draw power from the parallel kit outlet, never from improvised wiring. Any connection to a fixed installation, such as a cabin, must be done by a licensed electrician using a proper transfer switch, in line with the Australian wiring rules under AS/NZS 3010. Refuel only with the engines off and cool.
The Bottom Line
A parallel pair gives campers the power of a larger generator in two lighter, quieter packages, with fuel flexibility and a built-in backup. The trade-off is a higher upfront cost and the need to buy parallel-capable units and a matching kit. If you run a caravan air conditioner or a mix of high-draw gear away from mains power, two 2kW inverter generators are a strong answer. Browse the Outbax portable generator range to compare models, rated outputs and noise levels, and confirm parallel capability before you commit.
