Twin charging from two 240v outlets?

Twin charging from two 240v outlets?

In another thread, BrianH mentioned,

"Damned if I can find the post, but someone used two 14-50s at a KOA campground simultaneously to get 80A. That's about 60 mph, AFAIK. [That] requires twin chargers and a special connector, of course."

Is this really possible? Does anyone know anymore about how to do this?

djp | 02. januar 2013

I think no way - Twin charger configuration only has one charging connection

aa012a | 02. januar 2013
aa012a | 02. januar 2013

They seem to be called "cheater cords", "cheater cables" or "cheater boxes". I would read about it but I don't think I would ever try it.

JohnQ | 02. januar 2013

Check out the blog which includes a mention of using a homemade apparatus to charge from two RV chargers at once. I presume it takes the two currents, ensures that they are in phase, etc, then passes it on to a dual-charger equipped S.

appljd | 02. januar 2013

The folks that are currently crossing the US in a Tesla Model S are using such a device to charge the car in about 4 hours... check out the blog They call it an "EVSE".

Brian H | 02. januar 2013

Thank you! Couldn't remember where I read about it.

jat | 02. januar 2013

The one thing to watch out for is you have to exactly match the current or else you are drawing too much on one of them. The current is going to take the path of least resistance, so if the resistance on one path is lower than the other, the current will be higher there. Personally I would back off the total current (like maybe 70A) just to make sure I didn't overheat one of the circuits.

olanmills | 03. januar 2013

Ah, okay, so you need some custom equipment. I'm not going to mess with that. It would have been nice if there was some off the shelf stuff you could buy and connect together. It would have been nice to have HPWC charging capability at the cost of installing a second NEMA 14-50 and a second mobile connector.

Brian H | 03. januar 2013

Peter, the EE OP there, refers to a promised technical post on making the Multi-Input EVSE. Too busy driving and sleeping, so far!

Others have done the same thing,but I don't have links.

jat | 03. januar 2013

Note that the blog post @aa012a links to talks about overheating the neutral wire, but that doesn't apply to using it to charge the Tesla since it doesn't even connect the neutral connector (it has no 120V loads).

nickjhowe | 03. januar 2013

They haven't described the EVSE in any of the blog posts yet, but you can see it in one of the pictures lying on the ground. It is a pretty hefty box.

brandtlings | 15. januar 2013

There is a Y adapter from Hubbell that combines to 50a 240v circuits to one 100a outlet. It's specifically marine equipment with twist lock connectors, but could be adapted for use charging the MS. It's really pricey though, cheapest prices around $3000.

Rod (17314)

lolachampcar | 15. januar 2013

The Open EVSE (Electric Vehicle Service Equip) I am working with.

With respect to two 50 amps Y'd into one, do a search. This is a dog with a LOT of fleas. It can work but the risks are high.