The Difference Between The Charging Cable That Comes With The Vehicle And The Tesla Charging Box.

[MACX]

can someone help me out in the understanding the difference between the charging cable that comes equipped with the vehicle and the Tesla home charger for $500.00.

a. I have a 60 amp breaker installed and I'm getting 26 miles per hour, with the vehicle charging cable.
b. if I install a Tesla home charger I will get 30 miles per hour with a 60 amp breaker is this correct or will I get more.

am I looking at this correctly...

please advise..

 

[TexasEV]

First of all if you have a 60A breaker on the outlet you plug the UMC into, it’s dangerous and needs to be changed. The electrician should have known better— that’s an obvious code violation. The 14-50 outlet should have either a 40A or 50A breaker. The UMC plugged into that outlet has a maximum draw of draw 32A. (You really should think in amps rather than miles/hr).

With a 60A circuit the Wall Connector can supply 48A. (Note it’s called the Wall Connector, not Charger. The charger is in the car). This means the car will charge 50% faster than with the UMC. Whether that’s worth it depends on your charging pattern. If it just means the car will finish earlier during the night, the faster charging wouldn’t have any practical benefit for you.

More information can be found on the Tesla Home Charging web site:
Home Charging Installation
One of the links will have a table of charging rates in miles/hr for given amps for each model car.

 

[Rocky_H]

I have a 60 amp breaker installed and I'm getting 26 miles per hour, with the vehicle charging cable.

HOW in the m#@%^ f*%=ing WORLD do so many people keep doing this?!?! A 14-50 outlet on a 60A breaker is always wrong under any circumstances. Where do people even get the notion to do this?

I'm scared to even ask, but we probably should: what gauge wire is on that messed up circuit?

Other than that, yeah, the differences between the mobile cable and the wall connector are the mobile having a 32A limit, and the wall connector having much higher capabilities, depending on what size circuit it's on.

 

[Rkilian]

I don’t think the previous statements are correct. In the end, regardless of the power feeding the car, it’s the inverter in the car that limits the power fee to the vehicle. In early versions the cars had 72A inverters if I’m not mistaken. But now, that has gone way down to the point where it doesn’t make a big difference. The one benefit of the home charger is that it can share a single circuit with multiple chargers in case you have multiple Tesla’s.
That’s why to get faster charge you need to go direct to the DC bus and bypass the inverter.

 

[Rocky_H]

I don’t think the previous statements are correct.

That's because you're not quite understanding what we're talking about, apparently.

In the end, regardless of the power feeding the car, it’s the inverter in the car that limits the power fee to the vehicle.

Well that's false, or at least way oversimplified. It's either or both, depending on the hardware in the car and the installed hardware on the charging circuit. It's not always the device in the car, which is a rectifier, by the way, not an inverter. An inverter takes DC and creates AC. The charger in the car is doing the opposite of that, which is a rectifier.
Let's say you had only a 20A circuit and EVSE, but the car has the 48A capable charger. Well, 16A is all the current the EVSE is offering, and the device in the car is not the limiting factor.

But it could be the other way, that the EVSE is on a very big 100A circuit. Then, yes, it could be the car that is the limiting factor.

So yes, it matters some to know what the car's capabilities are and what your house's electrical capabilities are, so you can find a good balance between those two limiters to find something that meets your needs.

 

[ewoodrick]

First, the chargers are in the cars. What you are referring to is essentially a fancy extension cord. Different cords have different capabilities. The UMC mobile connector that comes with the car has the most flexibility and is probably the cheapest. The wall mounted HPWC looks prettier and can provide slightly more current to charge slightly faster. BUT, the charge is limited by what the car can do.

The difference between the options that you present is miniscule. Assuming that you don't have a 250 mile daily commute, the car will generally be charged overnight. Most folks commonly only take a few hours daily, others take a few hours weekly.

 

[Rkilian]

That's because you're not quite understanding what we're talking about, apparently.

Well that's false, or at least way oversimplified. It's either or both, depending on the hardware in the car and the installed hardware on the charging circuit. It's not always the device in the car, which is a rectifier, by the way, not an inverter. An inverter takes DC and creates AC. The charger in the car is doing the opposite of that, which is a rectifier.
Let's say you had only a 20A circuit and EVSE, but the car has the 48A capable charger. Well, 16A is all the current the EVSE is offering, and the device in the car is not the limiting factor.

But it could be the other way, that the EVSE is on a very big 100A circuit. Then, yes, it could be the car that is the limiting factor.

So yes, it matters some to know what the car's capabilities are and what your house's electrical capabilities are, so you can find a good balance between those two limiters to find something that meets your needs.

Rocky, first excuse the error in my term. Regardless, I do understand perfectly what the discussion was. The fact is that adding a 100 amp service and going through the expense of a new circuit, disconnect box and charger will not yield a 3X charging speed as the “rectifier” in the Tesla’s is now rated for 48 amps vs 72 amps on previous versions. So you would get a marginal 16 amp increase for a significant cost of installation.
Also regardless of the fuse size on a 14-50 connector (which shouldn’t exceed 50 amps completely agree with you) the charger is limited to 32 amps. So whoever is changing the fuse size is really just potentially inviting a melted cable and fire in a wall.

 

[MACX]

First, the chargers are in the cars. What you are referring to is essentially a fancy extension cord. Different cords have different capabilities. The UMC mobile connector that comes with the car has the most flexibility and is probably the cheapest. The wall mounted HPWC looks prettier and can provide slightly more current to charge slightly faster. BUT, the charge is limited by what the car can do.

The difference between the options that you present is miniscule. Assuming that you don't have a 250 mile daily commute, the car will generally be charged overnight. Most folks commonly only take a few hours daily, others take a few hours weekly.

the vehicle has the ability to do 72 amp.

 

[MACX]

the vehicle has the ability to charge 72 amp, so what I'm seeing in the post is the wall charger will make a difference.

 

[COrocket]

the vehicle has the ability to charge 72 amp, so what I'm seeing in the post is the wall charger will make a difference.

Since you are currently charging at 26 MPH and your car has a 72A charger, I’m guessing you have the first generation mobile cord hooked up to a 50 amp outlet that is drawing 40 amps of power into the car.

Besides the hardwired install, the $500 wall connector has a thicker cable and is capable of outputting up to 80 amps of power, as opposed to your mobile connector that is limited to 40 amps. In order to charge your car at the full 72 amps, you’d have to purchase the $500 wall connector, then have it hooked up to a 90 amp circuit breaker. It would be critical to ensure your electrical panel could handle that load, and the correct wire is used in the installation. You’d have to consult an electrician to see the costs of doing this.

The upgrade should result in your car charging at around 45 MPH. It’s up to you whether the faster speed is worth it depending on your driving habits. If the average person drives 50 miles a day, the difference between the car taking 1 hour or 2 hours to charge every night doesn’t have any practical value if it’s left plugged in overnight. That’s why I stuck with the mobile connector cause it can still charge the car completely if I need it. But some people like the idea of the capability to charge faster, and that’s fine too.

 

[Rocky_H]

Regardless, I do understand perfectly what the discussion was.

Nope--still don't.

The fact is that [...]

...and again gives only the example of when the charging circuit is bigger than the car's onboard charger.

This is where you're not getting my correction. You gave an absolute, one-sided, blanket statement that it is the car's onboard charger, which will always be the limiting factor. But onboard chargers could be several sizes, and the installed circuits could be several sizes. So no, it is not always the car's charger that is the limiter. People need to check find out both to decide on a solution.

 

[MACX]

Since you are currently charging at 26 MPH and your car has a 72A charger, I’m guessing you have the first generation mobile cord hooked up to a 50 amp outlet that is drawing 40 amps of power into the car.

Besides the hardwired install, the $500 wall connector has a thicker cable and is capable of outputting up to 80 amps of power, as opposed to your mobile connector that is limited to 40 amps. In order to charge your car at the full 72 amps, you’d have to purchase the $500 wall connector, then have it hooked up to a 90 amp circuit breaker. It would be critical to ensure your electrical panel could handle that load, and the correct wire is used in the installation. You’d have to consult an electrician to see the costs of doing this.

The upgrade should result in your car charging at around 45 MPH. It’s up to you whether the faster speed is worth it depending on your driving habits. If the average person drives 50 miles a day, the difference between the car taking 1 hour or 2 hours to charge every night doesn’t have any practical value if it’s left plugged in overnight. That’s why I stuck with the mobile connector cause it can still charge the car completely if I need it. But some people like the idea of the capability to charge faster, and that’s fine too.

First of all thank you for your input..I have the first generation mobile cord hooked up to a 60 amp outlet and yes drawing 40 amps of power into the car. going from 26 MPH to 45 MPH would also cut down on electricity use. I can get the job done just for the price of the parts and the price of the wall connector.

 

[Rocky_H]

First of all thank you for your input..I have the first generation mobile cord hooked up to a 60 amp outlet

I notice you did not respond to my earlier questions about this. This is a wrong and code-violating installation and needs to be changed immediately. You are never allowed to have a 50 amp outlet type with a 60 amp breaker.

 

[jboy210]

I notice you did not respond to my earlier questions about this. This is a wrong and code-violating installation and needs to be changed immediately. You are never allowed to have a 50 amp outlet type with a 60 amp breaker.

I agree. NEMA is pretty clear on that the max amperage for the NEMA 14-50 is 50 Amps. You might get by with 60A, but maybe not. And if you have a fire or had a unexplained surge while charging will insurance pay a claim, or Tesla fix you car?

 

[20854]

can someone help me out in the understanding the difference between the charging cable that comes equipped with the vehicle and the Tesla home charger for $500.00.

a. I have a 60 amp breaker installed and I'm getting 26 miles per hour, with the vehicle charging cable.
b. if I install a Tesla home charger I will get 30 miles per hour with a 60 amp breaker is this correct or will I get more.

am I looking at this correctly...

please advise..

I have a Tesla wall Connector on a 60 amp breaker, drawing 48 amps and charging my 2019 X Raven Long Range at 35 mi/hr.

 

[20854]

I notice you did not respond to my earlier questions about this. This is a wrong and code-violating installation and needs to be changed immediately. You are never allowed to have a 50 amp outlet type with a 60 amp breaker.

Agree. It’s a code violation.

 

[animorph]

We could use more info.

Sounds like you have something like my 2017 Model X. I have a 72A charger in mine. The most recent X's only have 48A chargers. Earlier X's have had 40A or 80A chargers. So we needed to know about the 72A car charger, and not just a guess.

Sounds like you have a Gen 1 UMC, 40A max, from what others have said. The most recent X's have a 32A UMC.

We've been assuming you are using a NEMA 14-50 outlet which mates with most UMC's (except the most recent) without an adapter. This outlet is rated at 50A max. You are saying you have a 60A breaker. Which would be a fire danger. If you are wired for 60A to the outlet but use a 50A breaker for now, no problem. If you are wired to a different style 60A outlet, no problem other than adapting to the UMC.

I have two HPWC's (now just Wall Chargers) connected to a 100A circuit with a 100A breaker. They can supply up to 80A to one car or 40A to both cars. My X can charge at 72A with it, the limit of the car's charger. Our 3 can charge at 48A with it, the limit of the car's charger.

So you are currently charging at 32A to 40A, depending on your UMC. You can increase that to 48A with a Wall Connector on a real 60A circuit, providing your in-car charger allows greater than 40A. You would need a 90A circuit for the Wall connector to charge at 72A, if your car is capable of that.

So I'm thinking you'd go from 40A with the UMC to 48A with a Wall connector on your current 60A circuit (if that's the case). Only a 20% charge speed gain. If you could rewire with a 90A circuit to the HPWC you would get your full 72A. That's an 80% charge speed gain. That would be nice for quick charges between a long commute and a long trip at night. But hardly anyone seems to really need that.

 

[P85_DA]

Earlier X's have had 40A or 80A

X’s only had 48 or 72... older S they had option of single 40a or dual 40s