You can run two generators together by connecting two parallel-capable inverter generators with a parallel kit. The kit combines their output so you get close to double the power from one set of outlets, often including a 30-amp RV outlet. In most cases the two generators need to be the same make and model. Honda, for example, says you can only parallel two identical units, with a few listed exceptions. Regular (non-inverter) portable generators generally can’t be paralleled at home.
How parallel generators work
An inverter generator makes AC power electronically, so its output frequency and voltage are tightly controlled. Parallel-capable models have extra terminals that let two units match their output to each other. A parallel kit links the terminals and feeds the combined power to its own outlets.
Conventional generators make power straight from an alternator spinning at engine speed. Their output drifts as the load changes, and joining two of them safely takes synchronizing equipment that portable generators don’t have. That’s why parallel kits are made for inverter generators.
What you need
- Two parallel-capable inverter generators. Look for “parallel ready” or “parallel capable” in the specs, and parallel terminals on the control panel.
- The parallel kit for those models. Kits are usually sold by the generator maker. Champion, for example, has a parallel kit selector to match kits to its models.
- A flat, open spot outdoors for both generators, well away from doors, windows and vents.
Can you parallel different brands or models?
Usually not. Here’s what the manufacturers say:
- Honda says you can only parallel two identical units, such as two EU2200i or two EU3000is. The exceptions are the EU2200i with an EU2200i Companion, and an EU2200i with an EU2000i only within certain serial number ranges. Honda warns other combinations can produce low voltage that damages connected tools and appliances.
- Champion says its generators are made to parallel within the same series and that pairing different brands can cause electrical imbalances, inefficiency or damage.
- Yamaha sells a “Twin Tech” kit for pairing its own matching models.
RV electrical expert Mike Sokol reached the same conclusion after checking with manufacturers: pair identical models. Mixing brands or sizes can void your warranty, even if a third-party “universal” kit claims it works.
How much power do you get?
Roughly double one generator, minus a little. Use the running (rated) watts of each generator, not the starting watts, when you plan your load. Two Honda EU2200i generators, each rated at 1,800 running watts, give you about 3,600 running watts together.
| Pair | Running watts each | Running watts together | Good for |
|---|---|---|---|
| Two 2,000-watt class inverters | About 1,600 to 1,800 | About 3,200 to 3,600 | A 13,500 BTU RV air conditioner plus small loads |
| Two 3,000-watt class inverters | About 2,800 to 3,000 | About 5,600 to 6,000 | Larger RVs, fridge and freezer plus a window AC |
Honda notes that you get the power of both units, but each outlet is still limited by its own rating. A 30-amp RV outlet tops out around 3,600 watts no matter how big the generators are. See what size generator you need for a 30-amp RV and what you can run on 3,500 watts.
How to connect two generators in parallel
- Read both owner’s manuals and the kit instructions. The order of steps varies by brand.
- Place both generators outdoors on level ground, side by side, far from the house or RV openings. Here’s how far a generator should be from your house.
- Turn both generators off and unplug everything.
- Connect the parallel cables to the parallel terminals on each generator, and the ground wire if your kit has one.
- Start both generators and let them warm up. Most kits only put out power when both units are running.
- Plug in your loads one at a time, starting with the largest, like the RV air conditioner.
- Turn off the loads before shutting down, then turn off both generators and disconnect the cables.
Never plug a generator, or a parallel kit, into a wall outlet to power your house. That can back-feed the power lines and is deadly for utility workers. Use a transfer switch or interlock instead. Here’s how to connect a generator to your home.
Two small generators or one big one?
| Two small inverters in parallel | One larger generator |
|---|---|
| Each unit is light enough for one person to carry | Usually needs wheels and two people to lift |
| Run just one when you need less power, which saves fuel and noise | Runs the whole engine even for small loads (unless it’s an inverter) |
| A backup if one unit fails | One point of failure |
| Two engines to maintain, plus the cost of a kit | One engine to maintain |
| Combined output limited by the kit’s outlets | Often has a 50-amp or 240-volt outlet for a transfer switch |
For RV camping, two small inverters are hard to beat. For backing up a house through a transfer switch, a single larger generator with a 240-volt outlet is usually simpler.
Related guides: What is the Difference Between a Generator and an Alternator, How Does An Electric Generator Work and What are Low THD Generators.
FAQ
Are generator parallel kits universal?
No. Most kits are made for a specific brand and model. Some third-party kits claim to work across brands, but generator makers warn that mismatched units can be damaged and that it may void your warranty.
Can I parallel a 2,000-watt and a 3,000-watt generator?
Generally no, unless the manufacturer lists that pair as compatible. Most only support two identical models.
Can I parallel two regular (non-inverter) generators?
Not with a simple kit. Synchronizing conventional generators takes special switchgear, which is used for large standby systems, not portable generators.
How do generators share the load in parallel?
The inverters talk through the parallel cable and match their voltage and frequency, so each one supplies part of the load. If you need more than one unit can make, both work together. If you need less, you can run just one.