Anyone use 10-50 plug to charge their Model S with Mobile Adapter?

I have built a few different adapters to convert to my NEMA 6-50 connector for my mobile adapter but haven't tried any of them yet. One outlet that is also 50 amps is the 10-50 outlet which was historically used for welders and such but does not have earth ground like 14-50 or 6-50 plugs do.

My question is has anyone actually tried using a 10-50 outlet to charge their Model S? I am assuming it will work and charge at 40A but wanted to make sure it would actually work as I plan to drive to my cabin about 150 miles away which has a 10-50 outlet in the garage. I can't really see how it could *not* work as there should be no way for the built in charger to actually detect that I am connected to neutral rather than ground but just checking.

I will eventually rewire this otulet to 6-50 or 14-50 so I have earth ground as well as neutral but that is a later project.

And just for clarity, my adapter connects the two line phases to the two line phases of the 6-50 connector and ties the neutral pole to the 6-50 ground wire.

I am just looking for actual experience to verify that it will work. I know I can just try it and am not looking for obvious common sense advice, just experience with this specific outlet configuration.

Just try it. Heck, what could go wrong? ;) (Please give gory details!)

It might not charge without an earth ground for voltage reference.

Pretty sure it will work and I am going to try but was hoping to hear from someone who has tried it just to have the confidence that I can get home without needing days to charge on a standard outlet.

This could be a big deal if it doesn't work; I'd be calling Tesla on that one! Ask to be put in contact with the electrical engineering department.

It will probably work. Just adapted a 3-wire electric dryer outlet to a 14-50 outlet and the mobile charger did not mind the missing neutral wire.


JackB, Did you mean the neutral wire or the ground wire? I realize in the implementation that you are doing it is really the same wire but I was wondering which leg of the 14-50 that you left disconnected. Or did you connect both ground and neutral together?

I would stay away from home made adapters and extension cords. I made a couple for my Roadster and they would not work. The Roadster actually detected them and stated "extension cord detected" and would not charge with them.

Instead, I would suggest you bring a 14-50 outlet with you to your cabin and swap out the outlet like JackB did above. Just make sure the wiring and breaker are rated for 50 amps.

Sorry to thread hi-jack but would any of you guys be willing to answer any of my questions on this? I really don't understand what magic goes on with the different outlet types, etc.

The Model S has both a unique and very advanced battery and charge system. Your Model S can detect and adjust to the line and current you feed it so as I understand it, if it fit's, it works with it.

The following is copied from this link
Then select the adapter guide tab

Volts / Amps Kilowatts Miles of Range per
Hour of Charge
NEMA 5-15 Standard Outlet 110 V / 12 A 1.4 kW 5
NEMA 14-50 RVs and Campsites 240 V / 40 A 10 kW 31
NEMA 6-50 Welding Equipment 240 V / 40 A 10 kW 31
NEMA 10-30 Older Dryers 240 V / 24 A 5.8 kW 18
NEMA 14-30 Newer Dryers 240 V / 24 A 5.8 kW 18

It does say if installing a new outlet 14-50 is recommended.

What if your outlet says 250V/50A? Is that still ok?


10 kW capable on-board charger with the following input compatibility: 85-265 V, 45-65 Hz, 1-40 A (Optional 20 kW capable Twin Chargers increases input compatibility to 80 A)

So yes, it's ok

@Scorch | NOVEMBER 27, 2012: What if your outlet says 250V/50A? Is that still ok?

That is just the maximum capacity rating of the outlet. The actual capacity is determined by your wiring and your circuit breaker. The circuit breaker should be 50A, but the current draw is usually 80% of the maximum rated capacity (or 40A). If you have a NEMA 14-50 or NEMA 6-50 outlet the car will draw the appropriate amount of power that it needs. So in other words, a 250V/50A rated outlet is fine.

@Alex Thank you so much! Hopefully I am good to go then. :)