Rate of charge at using a NEMA 14-50 outlet

[volkerbradley]

I've made arrangements to charge my P90D at a campground in the Upper Peninsula of Michigan. They have NEMA 14-50 plug.
If my battery is at 20% when I start charging and I plug in at my Tesla 80 AMP home charger, the display states that the charging rate is about 41 miles/hr.
If the car battery is 20% when I start charging, what would the charging rate be at a 50 AMP connector at a campground?

 

[Joe Harsanyi]

Should be about 29 mph........see here.

Tesla Charging | Tesla Motors

 

[eye.surgeon]

Yes it will be aprox 30 mph. That's my set-up at home. Keep in mind a 50 AMP connector is going to actually put out 40 AMPs.

 

[MorrisonHiker]

I'm assuming the OP is asking about an X, not an S since this was posted in an X forum and they have a Sig X listed in the signature.

From Home charging installation:

Simply plug your Mobile Connector cord with the NEMA 14-50 adapter into the outlet and the other end into your vehicle. This installation will provide a recharge rate of about 29 miles of range per hour of charge for Model S and about 25 miles per hour for Model X.

 

[rypalmer]

Slower in Canada unfortunately. In Canada the 14-50 connector is limited to 32 amps continuous, 80% of what it will do in the US.

 

[TexasEV]

Also know that battery state of charge doesn't matter with AC charging as it does with a supercharger. The 25 miles/hr for an X or 29 miles/hr for a S is if you're charging from a 14-50 at the full 40A. At many campgrounds the wiring isn't good enough to sustain 40A and you have to set the charging to a lower amperage, maybe 30A. You can calculate the charge rate ahead of time based on the ratio, or it will be displayed on the screen.

 

[Evbwcaer]

So an X on a 14-50 in Canada would be only charge about 20 miles of range per hour?

(25mph/40amps = 20mph/32amps)

 

[SabrToothSqrl]

Great... now I have to ask... why is it slower in Canada if it's the same connector?

 

[eye.surgeon]

US mandates a 20% reserve from rating to output for safety, hence 50amp rated outputs 40amps. Canada for whatever reason mandates more of a safety buffer. Maybe because they're more polite.

 

[Evbwcaer]

So how does Tesla comply with this limiting?

If a Canadian Tesla comes to the US, will it pull 40a from a 14-50?

Just wondering how this is implemented: umc, car's home, gps?

 

[MorrisonHiker]

So how does Tesla comply with this limiting?

If a Canadian Tesla comes to the US, will it pull 40a from a 14-50?

Just wondering how this is implemented: umc, car's home, gps?

I believe that the resistor in the 14-50 adapter is different.

This thread should have all the details that were discussed last fall: New UMC?

 

[umeshunni]

25mph/40amps = 20mph/32amps

Well, once you convert it back into kmph, it all works out (32kmph/32amps)

 

[Evbwcaer]

I read through MorrisonHiker's linked thread. If I was in Canada I would buy a US spec 14-50 UMC adapter and use it whenever I can confirm a 50 amp breaker is serving the outlet.

 

[rypalmer]

US mandates a 20% reserve from rating to output for safety, hence 50amp rated outputs 40amps. Canada for whatever reason mandates more of a safety buffer. Maybe because they're more polite.

Probably something about most NEMA 14-50 outlets being on 40 amp circuits instead of 50 amps. Just speculating.

 

[ccutrer]

My X is charging at 40A, 236-240V, 26mph on my 50A breaker, 6-3NM 14-50.

Hmmm.... a 14-50 adapter that automatically limits to 32A? That would be perfect for the 14-50 at my parent's house on a 40A circuit with 8-3NM.

 

[volkerbradley]

I'm assuming the OP is asking about an X, not an S since this was posted in an X forum and they have a Sig X listed in the signature.

From Home charging installation:

Thank you for the information

 

[gfb107]

Brought out Model X 75D home last night, and plugged it into out 14-50 outlet. It was at ~50% charge, both the in-car screen and the iPhone app showed it was charging at 28mi/hr.

 

[TexasEV]

Brought out Model X 75D home last night, and plugged it into out 14-50 outlet. It was at ~50% charge, both the in-car screen and the iPhone app showed it was charging at 28mi/hr.

That's what is expected, 28-30 mph depending on what voltage the car actually gets (240V isn't always exactly 240V). The SOC does not affect AC charging rate as it does with supercharging-- until the very end at 98% or so.

In car screen and iPhone app will always say the same as they're reporting from the same data source.

 

[volkerbradley]

Should be about 29 mph........see here.

Tesla Charging | Tesla Motors

I charged at that campground. I noted that it charged at 22 mph.