Mismatched Inverter Gens Paralleled

I've been wanting to find and spend some time to play and experiment with these 2 inverters for a good while now. A few days ago I was finally able to take a coupla hours and have some play time/experimentation with these two. I hope the pics give the results that my explanation(s) may not.
(BTW, even tho it's noon, because of the time of year, it's a challenge to not have glare in the photo's. I tried but...)

Just to stipulate, all of what you see here/below will be used only for 120v usage, no 240v!

To start, the inverter gens are the B & S P2200 (111cc) and the Radley 2500 (79cc), both are parallel capable right out of the box. Here's a pic basically showing everything I used this day. 4 or 5 adapter cords, kill-a-watt meter, multi meter, AC line seperator, 75 watt power inverter, quick attach tach and a 10/4 L14-30 extension cord.



I've adapters coming out the ying-yang but they all serve a purpose depending on application.



B & S no load Eco off



Same test using the 75 watt power inverter in the 12v lighter socket.



Now with the Radley



First time I've ever tested/ran the numbers on one of these. Interesting. I recieved it as a stocking stuffer gift many years ago (before USB's were a vehicle staple). I've only used it a few times for simple phone charging while on the road & a coupla times while camping. I was a bit taken aback with the low voltage numbers.


No loads applied, using my quick attach tach, I ran both gens with ECO on and off. (The B & S has a larger cc engine 111cc vs 79cc).







Using this parallel combiner adapter cord (along with the Champion L14-30P to Nema 5-20R Y adapter) I was able to get the same 123 & 124 volts from both gens. Not what I call a true parallel cord as each gen acts independently of each other, ramp up is individual depending on the load applied, there is no syncing that I found. The ground and nuetral are paralled, but each gen has it's own hot leg on the L14-30R.
I guess this cord may have it's place, however I dont see myself using it much, if at all. I may exchange the L14-30R plug to a L5-30R in the future to make a full sync.
Anyway, seperately I ran approx 2250 watts to each gen (with a 750/1500 heat gun and a 750/1500 oil heater) for a short test period with no overload warning. However the addition of any further wattage either would quickly flash the overload light (seperately, not in sync).





(I'm in no way advocating anyone doing this!) But being a tad dis-appointed in the previous cord, I decided to continue the experiment and made up my own parallel cord using roughly 7' of 12/3 stranded wire, two Nema 5-15P male plugs and a L5-30R receptacle mounted to a piece of 3/4" plywood.
Because this worked so well (exactly as a parallel cord should), for safety's sake I'm in the process of locating some banana plugs to replace the Nema 5's and will also add a 30 amp breaker to the box.

To fullfill the operation, I used an AC Works L5-30P to L14-30R adapter (orange one) plugged into the L5-30R paralled receptacle, attached to this is the Champion L14-30P Y adapter (yellow one) plugged into the L14-30R end of the orange adapter. The Y adapter has two 5-20 120v females. (phew! I hope that makes sense).

Onward...Both inverter gens synced up immediately, it didnt seem to matter which one I started first. (I'm going to assume it's because they both offer similiar wattage?)
With the ECO on (both units), using the heat gun and the oil heater, I applied 750 first, slight ramp up from both machines, 1500 a little more, 2250 more yet and with the full 3000 watts they were both performing flawlessly. No hint of an overload, both engines running smoothly. Happy camper 👍
With everything maxed out at 3000 watts the kill a watt was showing 119.9 volts, 59.9 Hz when checked from either plug of the Y adapter. Unfortunately I missed an amp pic, however both units are rated at 14.2 amps. Next time I have them out for excersise I'll be sure to take an amp pic with the kill a meter.




Altho it's hard to see in the pic, but with no load the voltage for the synced gens (ECO on) was showing 124v.



The pic doesnt show it, but I also tested a bonding plug plugged into a receptacle while they were paired. Again it made no difference which gen it was plugged into, both units then became NG bonded instead of the factory set free floating.



Like said earlier, I'm not recommending anyone using Nema 5P-15 120v plugs to create a parallel cord(!), as the majority of us know either end will be live and hot if one becomes unplugged with the generators running. I will absolutely be replacing those 120v plugs with banana plugs in short order.
Until then should only one inverter unit be used with the above parallel cord I have an empty 5R-15 female plug to slip over the unused end for safe use.



Another route I can take with these 2 inverters is to pick up (or make) a typical honda parallel cord (for example) and use that along with the AC Works 15amp 120v to L14-30 adapter. (Altho there is no pic and I certainly do not recommend[!], I did do a test with a double male cord from receptacle to receptacle with success. As stated, simply a test).
This adapter is great even on it's own when used singular with either of these gens as long as I'm not needing more than 2000 watts.






I hope this post is fruitful to anyone taking the time to read. As you have seen, it is absolutely possible to parallel mismatched name brand inverter generators. Generally speaking, I personally dont think electricity gives a hoot what inverter brand it comes from. Of course there may very well be certain brands/models that wont, but thankfully (as proved) mine do. Very happy about that.
The manufacturers all warn against it, I 'suspect' it is due to them wanting you to purchase another of their models. Cant blame them for that, it's all sales marketing IMO. I admit matching units will always look great.

Adapter cords...If you shop around, you'll find there's are a slew of them out there that can satisfy almost any need. I can only suggest sticking with a name brand as I believe they offer higher quality. I got turned on to AC Works after I was gifted the 5-15 to L14-30, but I'm also fond of Champions offerings of adapter cords. (My findings, not meant to be a sales pitch)

As stated earlier, even tho I'm using L14-30 plugs, I'm using for 120v with NO 240v intentions.

Edit to Add...I recently put 5 hours with the above units in parallel and was pleasantly surprised and elated with the outcome. Because of the much lower DB level and superbly increased fuel economy I think this pairing may be my 'go-to' for the next while. 👍

All of the above in this post are from my hands on testing and opinions. Of course your own results may vary...