NEMA 14-50 or Tesla Wall Connector

[Lamlamz]

Getting my SR soon. Wondering what are your thoughts on having 2x NEMA 14-50 vs 2x Tesla Wall Connectors with load balancing?

I understand the extra cost with Tesla Wall Connector and its benefit. Want to future proof for Model X.

How likely having two cars charged at the same time? Is it realistic? I understand the NEMA option is the most cost effective but does not offer load management thus charging at the same time is not possible. Also with NEMA I think we have to use the Mobile Connector + Adapter, correct? If so it may seem the experience is not as seamless.

What are your thoughts?

 

[Tam]

...How likely having two cars charged at the same time?...

If you have only 1 EV then the likelihood is none.

However, like mine, I charge my Model X and Model 3 at the same time every night, so it does actually happen to me.

I install 1 HPWC at a wall for 1 car and the other one between the 2 garage doors for the other car and also to share between the 2 sides of the garage as needed.

I have them sharing the 100A circuit with the load-sharing communicating cable.

...I understand the NEMA option is the most cost effective but does not offer load management thus charging at the same time is not possible...

No load sharing but you can have 2 different outlets from 2 different circuits as long as your house load can support the simultaneous charging.

 

[NathanielHrnblwr]

The easy answer is 2x HPWC if you have money to burn and room for a 100a circuit in your panel. Otherwise, it depends on when you charge. If you have to charge at night due to time of use plans or similar, then you need to see what your window is. You also need to account for how much you drive.

Here's a chart: Gen 2 NEMA Adapters

Let's say it's 12a to 6a. That's 180 miles of charging. Do you drive 180 miles a day in one car? how about two? You can schedule car 1 to start at midnight and car two to start at 3, etc.

If you have a larger charging window, then you can get more range assuming you need it.

If you have tiered rates and can plug in and charge anytime, then 14-50 would be plenty.

it all depends on how much you drive.

 

[snowmelt]

I have a 14-50 on a 50amp breaker and get a steady 30 mph charge. the Tesla wall charge and an 80amp breaker gets you about 36. Not worth the extra $500 plus in my opinion. Also, not adapters needed. I just leave the charger that came with the cable at home. Keep the adapter in the car that you might need for a public charging station, of course nothing needed at superchargers

 

[jerry33]

I charge two cars at 32/33 amps simultaneously. They are always completed by morning. One is a 14-50 (S85/33 amps) and the other is a Clipper Creek (Leaf/32 amps). 200 amp service. Has worked well for four years.

I only carry the UMC when on trips. There's zero need to carry it locally. If you are in a position where you need to carry a UMC all the time, either get the HPWC or a second UMC.

 

[Jffurlan]

Your SR can only pull 32A charge (LR can do 48A). As the UMC can only do 32A, you already have the optimized charging equipment. Wall connector will provide no benefit now, so I would wait to purchase when you have a need for it.

I’m using a NEMA 14-50, 40A breaker and charge times are amazing. 8kW, getting close to 15% per hour.

 

[Rocky_H]

Also with NEMA I think we have to use the Mobile Connector + Adapter, correct? If so it may seem the experience is not as seamless.

Well, on an individual level, yes, it would still be just as seamless, because you can leave your mobile charge cable plugged in permanently at home and coiled on a hook on the wall. I and many others have been going that way for years. You just grab it from the wall and plug it in, so it's the same as a wall connector.

But, if you do know you are going to have to charge two Teslas, it can certainly make the overall system more convenient to allocate the charging where it needs to go with the shared wall connectors.

 

[jerry33]

How likely having two cars charged at the same time? Is it realistic? I understand the NEMA option is the most cost effective but does not offer load management thus charging at the same time is not possible. Also with NEMA I think we have to use the Mobile Connector + Adapter, correct? If so it may seem the experience is not as seamless.

What are your thoughts?

My two cars almost always charge at the same time on a 14-50 / Clipper Creek setup (there would be no difference with two 14-50s). At the very least there is an overlap (one may start before the other, but there is always some time (minutes or hours) when both are charging at the same time.

There is no adapter for the Tesla side, There is always an adapter for the wall side (regardless of what type of receptacle you are plugging into) but in practice you never remove the adapter, so it's just as convenient.

What the HPWC offers is potentially a faster charge (depends on the car and battery size), a longer cable, and a hardwired connection. Also the HPWC can be installed outdoors. If none of those items are important to you, then the UMC/14-50 is the cost effective way to go.

 

[eprosenx]

This is not 100% inline to your question, but lots of good nuggets of things to think about on the debate between 14-50 and Wall Connectors.

How Should I Charge My Tesla? – Article625.com

 

[Lamlamz]

This is not 100% inline to your question, but lots of good nuggets of things to think about on the debate between 14-50 and Wall Connectors.

How Should I Charge My Tesla? – Article625.com

Thanks eprosenx. That’s helpful.

 

[Lamlamz]

My two cars almost always charge at the same time on a 14-50 / Clipper Creek setup (there would be no difference with two 14-50s). At the very least there is an overlap (one may start before the other, but there is always some time (minutes or hours) when both are charging at the same time.

There is no adapter for the Tesla side, There is always an adapter for the wall side (regardless of what type of receptacle you are plugging into) but in practice you never remove the adapter, so it's just as convenient.

What the HPWC offers is potentially a faster charge (depends on the car and battery size), a longer cable, and a hardwired connection. Also the HPWC can be installed outdoors. If none of those items are important to you, then the UMC/14-50 is the cost effective way to go.

Thanks for the insights. I think it makes sense to go with HPWC. I prefer lean and simple. I can keep UMC in the car.

 

[Lamlamz]

Well, on an individual level, yes, it would still be just as seamless, because you can leave your mobile charge cable plugged in permanently at home and coiled on a hook on the wall. I and many others have been going that way for years. You just grab it from the wall and plug it in, so it's the same as a wall connector.

But, if you do know you are going to have to charge two Teslas, it can certainly make the overall system more convenient to allocate the charging where it needs to go with the shared wall connectors.

Thanks that’s helpful.

 

[Logger]

I understand the NEMA option is the most cost effective but does not offer load management thus charging at the same time is not possible.

What are your thoughts?

Not an electrician someone feel free to me this is dumb. I'm not going to do it, but if you put both plugs on a 50amp breaker, could you just set each car to only pull 20 amps and manually manage the load?

 

[juliusa]

Depends on what you need. My suggestion would be start with 1 wall connector on the largest circuit your panel can support (up to 100amps). When you get a second car, see if the single connector meets your needs (charging on alternate days?). If not, add a second one. Also, you may want a second one simply because of where the wall connector is located and the way the cars are parked.

The sequence I suggest is the following. You don't have to start at the first step (my comment above jumps ahead).

1. Install 14-50 outlet on 50amp circuit, using #2 copper wire.
2. Replace 14-50 outlet with wall connector.
3. Upgrade to larger circuit - replace breaker and adjust wall connector setting.
4. Add second wall connector using same circuit.

Unless you panel is in the garage with room for two circuits, I really don't see the point of putting in 2 14-50s - especially if there is some subsidy for installing the wall connector.

 

[dhrivnak]

Getting my SR soon. Wondering what are your thoughts on having 2x NEMA 14-50 vs 2x Tesla Wall Connectors with load balancing?

I understand the extra cost with Tesla Wall Connector and its benefit. Want to future proof for Model X.

How likely having two cars charged at the same time? Is it realistic? I understand the NEMA option is the most cost effective but does not offer load management thus charging at the same time is not possible. Also with NEMA I think we have to use the Mobile Connector + Adapter, correct? If so it may seem the experience is not as seamless.

What are your thoughts?

It is easy to add a plug to the Tesla wall connector and use a NEMA 14-50. You will be limited to 40 amps vs 48 but you still fully charge overnight. I went with 3 NEMA 14-50 plugs in the garage for maximum flexibility.

 

[SoundDaTrumpet]

As of today, Tesla's in-car software cannot coordinate charge times for two cars avoid overlapping charging. Tesla passed on this responsibility to the wall connectors set up for load sharing.

Keep it simple with a wall connector, and leaving the mobile unit & adapters in the car. Use 1" conduit which is what the wall connector is threaded for and 3 AWG wire for 100A for future capability... you don't need that pictured junction box... the breaker box can serve as the junction.

Tesla did my install and added a wall connector. Inspector had no concern about the load calculation that I had (since I was keeping the existing non-Tesla charger). The paper work was looked over and approved beforehand, said the inspector. I imagine since the Tesla truck has almost all breakers sizes imaginable. If the house "can't take 100A," one could use a smaller circuit breaker down to ~70A which can clamp large wires.

 

[Rocky_H]

Not an electrician someone feel free to me this is dumb. I'm not going to do it, but if you put both plugs on a 50amp breaker, could you just set each car to only pull 20 amps and manually manage the load?

Well, the question of "could you?" is not really the same as "is it proper to...?"
There are things you can physically do, which will probably work OK most of the time, but definitely aren't proper or code-compliant.

I do have a friend who has something similar to that, but since the update of National Electric Code in the 2017 version, the answer to this is very specific and straightforward. Any outlet installed for the purpose of EV charging must be the only outlet on that circuit. Period. So you're just not allowed to put two outlets on the same circuit for charging two cars.

 

[jerry33]

Well, the question of "could you?" is not really the same as "is it proper to...?"
There are things you can physically do, which will probably work OK most of the time, but definitely aren't proper or code-compliant.

I do have a friend who has something similar to that, but since the update of National Electric Code in the 2017 version, the answer to this is very specific and straightforward. Any outlet installed for the purpose of EV charging must be the only outlet on that circuit. Period. So you're just not allowed to put two outlets on the same circuit for charging two cars.

Correct, but it's really just as easy to run two circuits and the cost isn't more since the time taken is just about the same because both sets of wires will be pulled at the same time. So you have the extra breaker, wires, receptacle, and installing the second outlet. (Assumes the two outlets are side by side.

 

[Rocky_H]

Correct, but it's really just as easy to run two circuits and the cost isn't more since the time taken is just about the same because both sets of wires will be pulled at the same time. So you have the extra breaker, wires, receptacle, and installing the second outlet. (Assumes the two outlets are side by side.

You are clearly making quite an assumption. I would expect that the reason a person is even considering this is because they don't have a 200A or 400A huge home electrical service to "just" add yet another 50A circuit and is seeing how they can get by with somehow sharing the single 50A circuit they were able to squeeze in. My house has only 125A main service, so that's the type of thing I will have to figure out too, when we eventually get another EV.

 

[jerry33]

You are clearly making quite an assumption. I would expect that the reason a person is even considering this is because they don't have a 200A or 400A huge home electrical service to "just" add yet another 50A circuit and is seeing how they can get by with somehow sharing the single 50A circuit they were able to squeeze in. My house has only 125A main service, so that's the type of thing I will have to figure out too, when we eventually get another EV.

What I did was up the service to 200 amps. Yeah, it wasn't that cheap, but it also got rid of the Federal Pacific main breaker box which was in the house when purchased.