Charging with a Generator - CT disconnects every time generator revs up.

[SamJoe]

I've got a 99 mile drive, from 350' to 7800' elevation, with a 5000+ lb box trailer, followed by 6 nights in the wilderness, and then a 95 mile drive back down to the nearest supercharger. There's no way the truck can do this on a full charge. I have access to a Predator 9500 Generator to charge while at camp, but its not working like I'd expect.

During my testing with the generator, I can't get it to provide more than 16 amps. If i bump up the amperage, the generator momentarily revs up and the truck disconnects the charging, every time. When I search this problem I get this: The generator voltage momentarily dips when the engine revs up, causing the Tesla Mobile Connector to disconnect as a built-in safety precaution. When the truck sudden requests more power, the generator's engine experiences a physical delay while accelerating to meet the load, causing a brief drop in electrical frequency or voltage that triggers the Tesla's sensitive protective safety switches.

The generator is more than capable of providing a full 24 amps, the problem is the truck disconnects every time the generator revs up to meet the demand. What am I doing wrong here. I'm using the Tesla Mobile Charger with the Tesla 14-30P adapter which will default the truck to draw 32 amps. This is plugged into a 14-30R adapter to the generators 240V, 30a 14-30L outlet. I'm really hoping to get 24 amps to dramatically reduce the hours I have to run the generator. Anyone have experience with this or what generator charging setup do you use?

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[Edphonse]

Is the generator a standard generator or an inverter generator? Also, are you at a high altitude while charging (usually >5000ft asl)? Most generators are carburated still and will have warnings saying use above 5000ft will require high altitude kits (different jetting) to prevent from damaging the generator. This could be causing the engine to struggle too much (engine would likely be running rich due to lower atmospheric pressure while fueling itself for a higher pressure) and not work correctly. At low loads, the engine could likely hack it for a while but eventually the engine will destroy itself.

If it is a standard generator, it's THD can get to crazy numbers in excess of 20% which I have seen on some models, which is bad for electronics and THD typically gets worse as you increase load on the generator. So if it is a standard, the CT could be disconnecting to prevent you from frying your PCS.

If it is an inverter generator, then it sounds like you have found the limit the inverter can handle on surge. You should make sure eco mode is off (if you have it) and slowly increase charging, 1 amp every about 15 seconds, to allow the generator to reach a steady state.

If that doesnt work, without buying a new generator you have 2 options without replacing your generator, one potentional and the second one i have only really seen on a handful of DIY posts for EVs.

Option 1 (not recommended but would most likely work) would be to get something like an UPS, but for something of that size, it isn't really an UPS. It would be a solar generator, such as the ecoflow delta pro x, to act as an intermediary between the generator and your tesla. I dont have an ecoflow (i do have some victron energy multipluses that I do something similar with but that is a completely different rabbit hole) so that may reject your generator too.

Option 2 (i can find them on amazon with a CCS2 connection so i am sure with enough digging, you might find a CCS1 or NACS) you can get a portable level 2 charger that takes in like 220-240vac and spits out 400vdc at like 6 or 7 kw. I have never used these and only seen them a few times on DIY forums so be careful if you choose that route.


Your better option would likely be just get a different generator. I have charged my CT off of a westinghouse igen4000dfc at 20 amps 120v via a 3rd party adapter for my mobile charger because tesla doesn't make a tt30 adapter. I recently got a westinghouse igen12000tfc which fits just perfectly under the tonneau cover but haven't charged off of it yet. I will try in the morning and let you know if it works for me using the nema 14-50 adapter.

Just to make sure, do you have a ground-neutral bonding plug on your generator when you run it or did it come from the factory with the ground and neutral already bonded? Your tesla app would say something along the lines of "bad neutral please check charging equipment" after a short period (maybe even immediately) of charging.

Edit:spelling/missing words

 

[SamJoe]

Thank you for your reply!
The Predator 9500 generator is an inverter generator. The generator is ground-neutral bonded so no plug needed. I am currently testing at only 350' elevation. Its rated for 7600 running watts (31.7a at 240V) with a surge capable up to 9500 watts, so I shouldn't be anywhere near its limit. I disabled eco mode before plugging in. The generator can handle the 16a draw at idle, and the truck charges just fine at that level with the generator at idle. I can bump up to 17a no problem, but as soon as i bump up to 18a, the generator revs up slightly, and in doing so, freaks out the truck, causing the truck to stop charging. I'm not sure if I should blame this on the truck or the generator. Surely every generator has to rev up at some point to match the load of the truck, why is my truck stopping charge every time this one does it? Thanks for the options, both are a bit pricey though, especially if I can just plug into a generator, like I know many have done.

 

[SamJoe]

When you are charging your CT with the generator, does it disconnect when the generator revs up or changes RPM at all? Or does your generator just hold a steady RPM at all times? What adapter are you using, I would be happy with 20a on one of the 120V outlets.

 

[dpoll995]

just an idea to test... maybe plug something else into the gene to get it to rev up the rpms and then plug in the mobile connector and slowly increase the amps to desired rate then remove other said device and see if it holds. maybe a hair dryer then while increasing the charge rate you can back down the hair dryer in order to keep the rpm up. not sure if it will work, just something to try.

 

[mongo]

I'm using the Tesla Mobile Charger with the Tesla 14-30P adapter which will default the truck to draw 32 amps. This is plugged into a 14-30R adapter to the generators 240V, 30a 14-30L outlet.

Do you mean 14-50 to 14-30 to generator?

What adapter are you using, I would be happy with 20a on one of the 120V outlets.

Did you mean 20A on a 240 outlet? 16A @ 240 is higher power than 20A @ 120V.

Other thoughts:
Have you ever pulled 7kW (or just > 16A) from the generator using any type of load? It might be defective.

Does the overload light on the generator come on?

 

[Edphonse]

As mongo said, 16 amps at 240v is more than 20 amps at 120v, it's almost double. Based on everything you have said, it looks like that is the limit of your generator/charger combo.

You can try what dpoll said, but it is unlikely to yield different results since your tesla is disconnect at a certain generator load. The generator, in general, doesn't care what that load is when talking about chargers and his idea would work for other loads due to a mechanic called reactive loads sometimes referred to as imaginary power. Power supplies/chargers typically have small reactive values compared to things like pumps/fans/motors/magnets or other objects with large inductors/capacitors build into them.

 

[Edphonse]

I just checked, my westinghouse igen 12000tfc charged my tesla at a full 32 amps for a minute before I turned it off. So it is likely just an inverter limitation on that predator series.

 

[SamJoe]

Do you mean 14-50 to 14-30 to generator?

I have the Tesla 14-50 and Tesla 14-30 adapters for the mobile charger and have tried both using an appropriate adapter to the generators 14-30L plug. Both give the same result.

Have you ever pulled 7kW (or just > 16A) from the generator using any type of load? It might be defective.

Good question. This is a borrowed generator and my only experience other than this is using it to run 4 refrigerators and 2 freezers for a week at camp using the generators 240w 30a outlet.

I just checked, my westinghouse igen 12000tfc charged my tesla at a full 32 amps for a minute before I turned it off. So it is likely just an inverter limitation on that predator series.

Thank you for checking, its good to know the Westinghouse igen 12000tfc works and fits in the bed of the CT. I'm assuming the gene revved up or down to match the load and the truck didn't have a problem with those changes?

I will also try dpoll995 idea this afternoon of using another load to get the generator revved up prior to starting the CT charging.

I've seen reports of others using the Predator 9500 generator to charge the Cybertruck not sure if anyone is on this forum has used it.
https://www.cybertruckownersclub.com/forum/threads/portable-generator-as-range-extender.33874/
https://www.facebook.com/reel/893424702816325
This guy shows him charging at 25amps using the Predator 9500

 

[SabrToothSqrl]

Not that it will solve your issue, but I've been able to charge my Model X off this guy, as a test mostly.

https://www.costco.com/p/-/firman-t...ectric-start-gas-co-alert/100840185?langId=-1

I have this to run my house since if a squirrel farts our power goes out. Not much fun on a well or when it's 20 degrees and snowing.

I'm hoping I can use the CT to power the house the same way (just off the 14-50).
I manually make sure to never exceed the capacity.

I've been able to charge up to (if I recall) maybe 28 amps, by baby stepping it up.
Start at like 16 amps (240v), then wait 5 min, just bump up, wait 5 min, then up, etc then up. But once it got too high, the generator I think cut me off. Maybe it was the car. Either way, it never let me reach 32 I don't think.

 

[Cybergirl]

I've experienced problems charging my Cybertruck with Tesla's mobile connector from two EcoFlow Delta Pros connected together to provide a 240VAC power source. The only solution I found was to switch to a Jowua NACS Mobile connector capable of charging at a full 48A. Tesla's mobile connector is so finicky about the power source.

 

[SabrToothSqrl]

Agreed - the 'wall connector' is a lot less finicky about the power than the Mobile Connector. You can (not legal advice), use a 6 gauge oven connector NEMA 14-50 and wall connector to make a mobile wall connector... or so the legend goes

https://www.amazon.com/Cable-Matters-Prong-14-50P-4-Wire/dp/B07TD9KPKJ

https://shop.tesla.com/product/wall-connector

For example, with the loop connectors removed and then wired to a wall connector, limited to 32 amps (or 40 if you're feeling frisky), (the old old school Tesla UMCs could pull 40 amps!)... might be less power finicky than a UMC.

Use at your own risk. not advice. Not an electrician.
Use under adult supervision. Don't do drugs. Stay in school.

 

[HaulingAss]

I've got a 99 mile drive, from 350' to 7800' elevation, with a 5000+ lb box trailer, followed by 6 nights in the wilderness, and then a 95 mile drive back down to the nearest supercharger.

Is this on the East side of Yosemite?

 

[SamJoe]

Is this on the East side of Yosemite?

This is driving from Bakersfield through Lake Isabella and into the mountains north of there. Near Big Meadow, if your familiar with it.

A supercharger station in Lake Isabella or Kernville would alleviate all this and be awesome!

 

[Edphonse]

My igen didn't rev that much to be honest. It started at 20 amps, that's what I usually have my nema 14-50 mobile connector set at and the second it started charging I switched it to 32 and it ran for about a min before I turned it off, well it turned itself off due to high co concentration because I didnt unstrap it and roll it away from the rear cabin wall XD but it ran at 32 amps for about a min, generator had time to stabilize and it said it had about 6 hours or fuel at that loading (~7.5 gal tank).

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