Choosing a generator for a caravan is not always about finding the biggest output you can afford. For some travellers, one larger generator makes more sense. For others, two smaller units can be easier to lift, store and manage on the road.
But first, make an important distinction: having two generators doesn’t mean you can connect them. Parallel operation is only possible with compatible models that are specifically designed for it.
So, before looking at the pros and cons of each setup, it helps to separate two questions: do you need one generator or two, and do you actually need parallel operation?
The Short Answer for Most Caravanners
A single 3.5kW-class inverter generator can make sense if you need higher continuous output from one unit, regularly run larger appliances such as a rooftop air conditioner, and have somewhere suitable to store and lift a roughly 38kg generator.
Two smaller generators can make sense if easier lifting, flexible storage, and backup matter more than having the full output of a larger generator from one unit.
The right choice depends on your caravan, your typical electrical load and how you travel.
Comparing the Gentrax Generators
The Gentrax GT2000, GTX3500 and GTX4200 Pro offer different approaches to portable power.
Figures below come from the specification information provided for each model.
| Specification | Gentrax GT2000 | Gentrax GTX3500 | Gentrax GTX4200 Pro |
|---|---|---|---|
| Rated continuous output | 1,700W | 3,200W | 3,500W |
| Maximum output | 2,000W | 3,500W | 4,200W |
| Engine | 100cc, air-cooled, 4-stroke OHV | 149.5cc, air-cooled, 4-stroke OHC | Not listed in manual |
| Fuel tank capacity | 4.1L | 7.5L | 8.8L |
| Run time at 50% load | 4.1 hours | 6.3 hours | 6.8 hours |
| Oil capacity | 0.52L | 0.9L | 0.70L |
| Net weight | 18.5kg | 37.5kg | 41.5kg |
| Gross weight | 21.0kg | 40.0kg | Not listed |
| Dimensions (L × W × H) | 525 × 282 × 458mm | 690 × 385 × 565mm | 610 × 415 × 495mm |
| Starting system | Recoil | Recoil, electric and remote | Recoil, electric and remote |
| Parallel outlets | Not listed | Not listed | Yes |
The weight difference is immediately noticeable. A GT2000 weighs 18.5kg, while the GTX3500 weighs 37.5kg.
That means two GT2000 units would weigh 37kg in total, almost the same as one GTX3500. The difference is how that weight is handled: two 18.5kg lifts instead of one 37.5kg lift.
However, you shouldn’t treat two GT2000 units as a 3.4kW parallel setup. The GT2000 is not listed as having a parallel connection, so buying two doesn’t let you combine their outputs.
Here’s what one of our customers said about the Gentrax GT2000 Inverter Generator:
“Neat compact unit, filled with oil and fuel, started a second pull. Runs like a dream and is nice and quiet.”
Two Generators Don’t Automatically Mean Parallel Power
This is one of the most important things to check before buying a second generator.
Parallel operation connects two compatible generators through a dedicated parallel cable or kit so they can supply a load together. It is not the same as simply owning two generators or plugging two generator outputs into the same appliance.
The Gentrax GTX4200 Pro, for example, has dedicated parallel outlets, and its manual sets out specific requirements for parallel operation.
These include:
- Both generators must be the same model and have the parallel function fitted.
- Connect the parallel cable before the engines are running.
- Both generators must be started separately and checked before connecting the load.
- Operate the economy controls together while the generators are connected.
- Disconnect the load and stop both engines before removing the parallel cable.
So if you’re considering a dual-generator setup, check the exact model for parallel capability before buying a cable or assuming the outputs can be combined.
The GT2000, for example, does not have the parallel connection required for this type of setup.
Caravan Ballast: Where the Weight Sits Matters
Weight is only part of the equation when you’re towing a caravan with a generator.
Tow ball weight is commonly estimated at around 10% of the loaded trailer mass, although the figure that applies to your caravan depends on its compliance requirements. Weight carried towards the front of the van can also affect the tow vehicle’s available payload and ball weight.
A 37.5kg generator stored in an A-frame box puts substantial weight forward of the axles. Two 18.5kg generators give you more flexibility in how you distribute that equipment, provided the storage locations are suitable and remain within the caravan manufacturer’s limits.
Fuel adds further weight. Petrol weighs roughly 0.74kg per litre, so a full 7.5L tank adds around 5.6kg to the generator’s weight. Transport the generator according to the manufacturer’s instructions, including any requirements to drain the fuel before transport.
Storage and Lifting: Two Parcels or One?
The GTX3500 measures 690 × 385 × 565mm, making it a substantial piece of equipment to fit into a caravan storage compartment.
The GT2000 is considerably smaller at 525 × 282 × 458mm. That can make a difference when you’re working with an under-bed locker, rear toolbox or another confined storage area.
Lifting is also a practical consideration.
An 18.5kg generator is considerably easier to move than a 37.5kg unit. Two smaller generators do mean two items to handle, but each individual lift is lighter.
That’s particularly relevant if you’re regularly moving the generator in and out of storage rather than leaving it in one location.
Fuel: Match the Generator to the Load
Generator fuel consumption depends heavily on the load, so published run times at 50% load help compare models but don’t tell you exactly what either generator will consume for every appliance.
The GT2000 has a 4.1L tank and a quoted 4.1-hour run time at 50% load. The GTX3500 has a 7.5L tank and a quoted 6.3-hour run time at 50% load.
For lighter loads, a smaller generator may therefore be a more practical choice than running a larger generator simply because it has more available capacity.
If your usual requirements are a fridge, lighting and battery charging, consider the generator output you actually need rather than automatically choosing the largest unit.
If you regularly need to power a high-demand appliance such as a rooftop air conditioner, however, the additional continuous output of a larger generator becomes more relevant.
Redundancy: The Case for Having Two Units
One advantage of carrying two separate generators is redundancy.
If one unit develops a fault, you still have another generator available for smaller loads. You may not be able to run every appliance you normally would, but you can still access portable power.
The trade-off is that two generators mean twice the equipment to maintain. That can mean additional spark plugs, air filters, oil changes and general servicing.
For occasional trips from powered sites, that extra equipment may not be worthwhile. For longer trips away from mains power, having a second generator may be more useful.
Which Setup Suits Your Caravan?
Powered sites and occasional trips
If you usually stay on powered caravan sites and only need a generator occasionally, a single unit may be the simpler option.
A GTX3500 provides 3,200W of rated continuous output and 3,500W maximum output from one generator, without needing to move or maintain two separate units.
Extended touring away from mains power
If you spend longer periods off-grid, portability and redundancy may matter more.
Two smaller generators can be easier to lift and store individually, and having a second unit means one generator can remain available if the other needs attention.
Just remember that two generators are not automatically a combined power source. If you need to run them together, both models must specifically support parallel operation.
Air conditioning and larger loads
If running a rooftop air conditioner is a priority, start with its actual electrical requirements, including its starting surge.
A larger generator may be the more straightforward solution when you need higher continuous output from a single unit.
The GTX4200 Pro is also designed for parallel operation, but any parallel setup must follow the manufacturer’s model and connection requirements.
Safety Rules for Both Setups
Whatever generator setup you choose, the same basic safety principles apply.
- Never run a generator in an enclosed space. This includes a tunnel boot or other enclosed storage area, even with the hatch open. Generator exhaust contains carbon monoxide.
- Allow the required clearance around the generator. The manuals specify operating the units outdoors on firm, level ground with adequate clearance.
- Take care with high-starting-current appliances. Compressors and rooftop air conditioners can require much more power to start.
- Transport the generator according to the manufacturer’s instructions. This includes requirements around draining fuel and keeping the unit upright.
- Follow the manufacturer’s earthing requirements. Use the specified equipment and connections rather than improvising.
- Keep generators protected from rain and check the oil before use. Low-oil protection can shut the engine down, but regular oil checks are still essential.
The Bottom Line
No single generator setup suits every caravan.
A single 3.5kW-class generator gives you higher output from one engine and one piece of equipment to store and maintain. Two smaller generators can make individual lifting and storage easier, while also giving you a second unit if one develops a problem.
But there’s an important distinction between owning two generators and running two generators in parallel.
The GT2000 is a useful example of why you need to check the specifications before buying a second unit or a parallel cable. Its manual doesn’t list a parallel connection, so you shouldn’t treat two GT2000s as a combined 3.4kW power source.
If you want parallel operation, look specifically for a model with the required parallel function and follow the manufacturer’s instructions.
Before choosing, consider your caravan’s storage space, tow ball weight, typical electrical load and how often you travel away from mains power. Those factors will tell you far more than the generator’s maximum wattage alone.
