Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Fast charging from 120V

Tdave

Member
May 16, 2008
760
78
Owings Mills, MD
Exactly what I thought. You are the first to ask, Dave.
Let me crunch some numbers.
Any thing to share yet, vfx? I'm actually thinking I could use this starting next month if the price is right. Would it be a new pigtail for the Eberhard style charging cable system? That would be ideal if possible.
 

Kipernicus

Model S Res#P1440
Dec 2, 2009
1,255
135
Belmont, CA
Finding a second out of phase circuit usually takes a long (50' min) 10G extension cord.

Would a 12 gauge extension cord work as well? They seem to be rated for 125V and 15A, and perhaps is not as heavy and cumbersome as 10G.
Finding this out of phase plug does sound like a pain (not to mention big extension cords running all over my in-laws' house). Is there some gadget that can plug into an outlet and tell me what phase it is?
 

hcsharp

Active Member
Jun 7, 2011
3,377
1,340
Vermont
Would a 12 gauge extension cord work as well? They seem to be rated for 125V and 15A, and perhaps is not as heavy and cumbersome as 10G.
Finding this out of phase plug does sound like a pain (not to mention big extension cords running all over my in-laws' house). Is there some gadget that can plug into an outlet and tell me what phase it is?

I made one of these before I saw this thread (and others on the same subject). I mounted a cheap volt meter in the box so I could see when I found opposite phases. The other thing you have to know is that it doesn't work with GFI outlets because each extension cord is only drawing off one wire per outlet. And as TEG has pointed out in other threads, once you plug in one cord, in some cases one prong of the other cord will be live if you touch it.

I later modified mine by adding a simple switch to the box to change between 120 and 240v. That way if I arrive at my destination and never find 2 opposing phases, I can still charge at 120v using the same device without having to carry a separate solution such as the spare mobile connector.

If Eric no longer wants to make these, I will make one for you for about $300 depending on length and gauge of extension cords. Or show you how I made mine at no charge.
 

vfx

Well-Known Member
Aug 18, 2006
14,790
40
CA CA
There was no interest worth the effort. I basically changed plugs on the Q220 box. Ittells you out of phase lines and worked great about a year and a half or so. Eventually on of the AC cords gave out, then the wall plug gave out and I replaced the home circuit breaker and the Q220 breaker kept tripping. The run was just too long at my home. Would be fine for the travelling EV though. I've upgraded my power now.
 

bart513

Active Member
Feb 27, 2013
1,331
92
East Hampton
I am not an electrical engineer or even an electric savvy person. Why not install a NEMA 6-15 outlet which works on a 15 amp circuit and cuts charge time to less than half of the regular 120V charger? You can use the UMC240 with the NEMA 6-15 pigtail, correct?
 

wcalvin

Member
Apr 3, 2013
310
16
Seattle WA USA
Apparently welders use this trick at construction sites.

Checking outlets: run an extension cord to second outlet. Poke voltage tester (one that shows 110, 220, 440 in separate LEDs) leads into nearby outlet and the extension cord female to find the pair with the highest voltage. If it is 110, both outlets are off the same side of the 220 feed line. If you get 220v readings, you may be in business provided that the extension cord can carry the amps without a significant voltage drop. You still have to have a box with a 220 outlet and two 110 inputs, plus a switch or circuit breaker.

And watch out for coils of wire, should you find the two outlets so close together that much of the extension cord stays coiled up: it is now only carrying one side of the line rather than two, and will generate a substantial magnetic field if remaining coiled.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top