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

It IS possible to charge at 24A from a 120V TT-30 plug...

This site may earn commission on affiliate links.

Cosmacelf

Well-Known Member
Supporting Member
Mar 6, 2013
12,639
46,690
San Diego
...if you have the dual car charger option. There is a thread over the Tesla Motors forum where we have found a Canadian user who happens to have dual chargers who has been able to charge at 24A from a TT-30 adapter. I have a single car charger in my car, and I can only charge at 20A with 120V. The few people that have tried charging with TT-30s must also have had single chargers because this is the first time I've heard of anyone charging at 24A from a TT-30.

If anyone here has a dual charger car and access to a 30A 120V source and has the appropriate home made adapters, it would be great if we could confirm this finding, but at this point, I don't have any reason to doubt it.

I still believe that the single charger 20A limit at 120V is a software limitation put in by an over zealous programmer who didn't realize that things like 30A TT-30 outlets existed.

----------------------------

Update 4/17/2013: At this point, the evidence is pointing to higher VIN cars being able to charge at 120V, greater than 20A, rather than dual versus single chargers.
 
Last edited:
A home-made TT-30 adapter, i.e., TT-30 to 14-50? Or is there some Tesla TT-30 adapter I don't know about?

Last time I tried (~4.0 or so) it limited at 20A. I could rig something up I suppose fairly easily, just move L2 to neutral and give it a spin.
 
Do you have dual chargers, FlasherZ? Yes, I am talking about a home made adapter, Tesla hasn't made a TT-30. And yes, you could rig something up to test it as you suggest - but again, it should work at 24A only if you have dual chargers (at least that's the current working theory).
 
Confirmed. 5.9 is limited to 20A - dual chargers. I just wired a set of P and R adapters 14-50 to L1-N instead of L1-L2 and the car showed "20A/40A" at 121V, remained there for several minutes.

I did not try, however, to reduce the charge current to 24A to see if it would balance differently. I might have time to do that later but dinner dates call. :)
 
Well, the other forum poster said he had v5.9. I'll try to find out what subversion he has. He also has a Canadian car if that makes a difference.

- - - Updated - - -

And what subversion of 5.9 do you have Flasher?
 
I don't see how only a dual charger car would only have this capability, as a single charger car can handle 24A at 120V just fine. I really doubt that Tesla would modify the software only for the dual charger cars.
 
Well, the other forum poster said he had v5.9. I'll try to find out what subversion he has. He also has a Canadian car if that makes a difference.

- - - Updated - - -

And what subversion of 5.9 do you have Flasher?

.94

- - - Updated - - -

I would like to see a screen shot of 120V/24A charging. I can't reproduce it here. Maybe there's something w/ Canada cars. I dunno.
 
.94

I would like to see a screen shot of 120V/24A charging. I can't reproduce it here. Maybe there's something w/ Canada cars. I dunno.

So here's the thread, and near the bottom is thierrY's post where he posts pictures. It definately works for him. He's on .94 as well and has dual chargers, but his car is Canadian spec. Hmmmm. I sent an email into ownership asking about this, but they referred me to my service center. Yeah right.

Anyone know the charge rate for a standard 120V/30A RV outlet? | Forums | Tesla Motors

- - - Updated - - -

Thinking more about it, it could also be VIN related. The Canadian poster's car is only three weeks old. My car is over a year old, and Flasher's car is even older. So it might not have anything to do with Canada versus US, or dual versus single charger, but instead have to do with how recent your car was made.

So, anyone reading this thread, if you have a VIN great than, say, 10,000, and you can test with a high amp 120V source, please let us know...
 
I know you were probably just joking anyway but if you are in the desperate position of needing to charge on a 120V outlet, I am guessing that, yes indeed, 5 hours difference could be important to you (approximately 24 hours at 24A vs 29 hours at 20A for 70kW of charge).

Cos,

4 additional amps @110v for the electrical maven ?

Is the juice worth the squeeze ? sorry, I had to....

- - - Updated - - -


Sorry if I missed this in the thread, but is he wiring to one hot and one neutral on the 14-50R to TT-30P adapter? I believe others have achieved higher amperage by wiring the 120V source to the two hots of 14-50. The car thinks you are at a 14-50 source with really low voltage. Maybe this doesn't work anymore now that the MS charger algorithm more carefully monitors the voltage but it used to work in the old days and would allow you to turn up the current on a 120V source.

So here's the thread, and near the bottom is thierrY's post where he posts pictures. It definately works for him. He's on .94 as well and has dual chargers, but his car is Canadian spec. Hmmmm. I sent an email into ownership asking about this, but they referred me to my service center. Yeah right.

Anyone know the charge rate for a standard 120V/30A RV outlet? | Forums | Tesla Motors

- - - Updated - - -

Thinking more about it, it could also be VIN related. The Canadian poster's car is only three weeks old. My car is over a year old, and Flasher's car is even older. So it might not have anything to do with Canada versus US, or dual versus single charger, but instead have to do with how recent your car was made.

So, anyone reading this thread, if you have a VIN great than, say, 10,000, and you can test with a high amp 120V source, please let us know...
 
Sorry if I missed this in the thread, but is he wiring to one hot and one neutral on the 14-50R to TT-30P adapter? I believe others have achieved higher amperage by wiring the 120V source to the two hots of 14-50. The car thinks you are at a 14-50 source with really low voltage. Maybe this doesn't work anymore now that the MS charger algorithm more carefully monitors the voltage but it used to work in the old days and would allow you to turn up the current on a 120V source.

This has never worked. I tried it way back in the v3/v4 days on my Sig car and tried it again the other night. If the car detects ~120V (I don't know the exact threshold), it will limit charging to 20A. Even if you set it up to 40A, it still shows (20A/40A).
 
Sorry if I missed this in the thread, but is he wiring to one hot and one neutral on the 14-50R to TT-30P adapter?

English is so imprecise. FlasherZ took a hot and the neutral from his 14-50 receptacle and wired it to the Tesla adapter 14-50's hot and hot. That way he was able to test charging the car with a high amperage 120V source.

I believe others have achieved higher amperage by wiring the 120V source to the two hots of 14-50. The car thinks you are at a 14-50 source with really low voltage. Maybe this doesn't work anymore now that the MS charger algorithm more carefully monitors the voltage but it used to work in the old days and would allow you to turn up the current on a 120V source.

That's essentially what a specially wired-for-Tesla-charging TT-30 adapter does.

To be precise, the car doesn't know that a 14-50 adapter is plugged into it, all it knows is that whatever adapter is plugged into the UMC is advertising a 40A maximum draw.

And that's the issue we are trying to solve - why certain people can charge at 24A on a high amp 120V source and others are limited to 20A.

Can you charge at 24A on 120V?
 
No luck...
uploadfromtaptalk1397763383515.jpg