Ideal amps for charging long range model 3 at home

[forestlinden]

Hi guys. I'm new here. Got a model 3 long range rear wheel drive a week ago. (This thing is like driving a spaceship!)

I had an electrician install a 220v 50 amp circuit in my garage for charging. I charged it up last night for the first time and noticed that the charging screen showed it was getting 32/32 amps.

First, if I had a 50 amp circuit installed, why is the model 3 only accepting 32 amps?

Second, I read in another thread that 32 amps is actually ideal for home charging. Is that accurate?

If so, I'll leave things alone and let this set up be as it is.

Thanks much for your help.

Cheers,
Forest

 

[WilliamG]

You only get 32A max at home using a Nema 14-50. The outlet is rated for 50A, but that’s irrelevant really as the car will only pull 32A max from that using the current mobile connector.

With the Tesla Wall Connector and a 60A circuit you’ll get 48A pull. That’s what I use.

I’ve not heard anything about “ideal” charging speed. So I’ll let someone else chime in there.

 

[forestlinden]

Got it. Thank you, William!

I'll try this first for a while and see if it's plenty of charge speed for regular home charging. I have a feeling I'll be fine as I don't drive a ton around town.

 

[Wennfred]

Long Range should be at minimum 60amps to be able to charge at 44 mph using the Tesla Wall EVSE. So look at the chart below.

 

[WilliamG]

The key with that above chart is those numbers are only for the Tesla Wall Connector, not the Nema 14-50.

 

[leporsche]

Hey bud,

The power supply that came with your car is the Gen 2 Mobile Connector:
Gen 2 Mobile Connector Bundle

This has a max output of 32A, even when using a NEMA 14-50 plug.

If you want to draw more power from your wall (sounds like your place is capable of giving 40A continuous), you would have to get an upgraded mobile connector:
Corded Mobile Connector
Or buy and install Tesla's Wall Connector:
Silver Wall Connector

In my personal opinion, neither of these options is worth it just for the sake of increasing charging from 32A to 40A.
I did buy a secondary mobile connector (the one capable of 40A that I linked), but that was mainly so I have an additional power supply. Now I just leave the 32A one in my trunk for charging at destinations (at someone's house, RV sites, etc.) or for emergency use.

Good luck with your new car! I think you're going to enjoy it as much as I enjoy mine - a lot!

 

[forestlinden]

Thanks guys! You are all so helpful in here. Such a cool community.

@Wennfred: awesome chart! Thank you!

@leporsche: thanks for the heads up on the connector being the limiting factor.

I didn't get the wall unit from Tesla because I had a feeling I didn't need to spend the $500 on that for the amount I drive around town (I work in my house and Boulder is a small town.)

But it's good to know about the option of the upgraded mobile connector.

I'll see how things go when setting the charge limit to 80% (yes I know there's a lot of threads about that amount, but that seems to be the consensus to set it to) and if need be will upgrade to the 40A connector or get a wall unit.

Most importantly, I can't wait for the antigravity levitation upgrade

 

[leporsche]

I didn't get the wall unit from Tesla because I had a feeling I didn't need to spend the $500 on that for the amount I drive around town (I work in my house and Boulder is a small town.)

I think your instincts are right. $500 plus install costs (or your time, if you're very handy) is a lot.

I'll see how things go when setting the charge limit to 80% (yes I know there's a lot of threads about that amount, but that seems to be the consensus to set it to) and if need be will upgrade to the 40A connector or get a wall unit.

Yup! 80% seems to be the sweet spot between battery health and convenience for most people. As you get more used to the car, you'll develop a better idea of what's necessary.

Most importantly, I can't wait for the antigravity levitation upgrade

I hear it's an OTA upgrade, too!

 

[Big Dog]

Most importantly, I can't wait for the antigravity levitation upgrade

you need the flux capacitors for that option, and flux only comes with HW4, which Elon has promised to anyone he thinks of, but only after Starman is upgraded.

 

[A2be]

@forestlinden , I'm in Colorado as you are and I'm going to install my own 50 amp NEMA 14-50 (240 volt) outlet on a new 60 amp rated circuit in the coming weeks. I'm going to add a 60 A breaker and wire rated for 60 A so that, should I want to in the future, I could easily add the Tesla Wall charger. But I'm confident the NEMA 14-50 outlet with 32 A pack charge rate (7.6 kW of power) using the Tesla Mobile Connector (Gen 2) will be far more than I'll ever need for driving of my standard range (SR) Model 3 around Colorado.

During my first month of Model 3 ownership, I've been using only the 15A/120V low-power household input to the Mobile Connector, and it's been plenty for my ordinary driving in Denver and surrounds. This adds just 5 miles of charge per hour, drawing 12 A (1.3 kW of power).

 

[gfunkdave]

@forestlinden , I'm in Colorado as you are and I'm going to install my own 50 amp NEMA 14-50 (240 volt) outlet on a new 60 amp rated circuit in the coming weeks. I'm going to add a 60 A breaker and wire rated for 60 A so that, should I want to in the future, I could easily add the Tesla Wall charger. But I'm confident the NEMA 14-50 outlet with 32 A pack charge rate (7.6 kW of power) using the Tesla Mobile Connector (Gen 2) will be far more than I'll ever need for driving of my standard range (SR) Model 3 around Colorado.

During my first month of Model 3 ownership, I've been using only the 15A/120V low-power household input to the Mobile Connector, and it's been plenty for my ordinary driving in Denver and surrounds. This adds just 5 miles of charge per hour, drawing 12 A (1.3 kW of power).

If you install a 14-50 you are required to put it on no more than a 50 amp breaker. THe 14-50 is only designed for up to 50 A.

 

[ngogas]

Ideal is any rate except the slow 110v 15 amp. You need patience with that one.

 

[Sophias_dad]

Not sure if I'm allowed to link this, but it suggests 32A is the best efficiency...

Is charging on a 110v outlet cheaper than a Nema 14-50? : teslamotors

I haven't verified their data, either.

 

[kbellairs]

If you install a 14-50 you are required to put it on no more than a 50 amp breaker. THe 14-50 is only designed for up to 50 A.

Pretty sure that’s backwards. Violates code to put a higher rated receptacle than the circuit is protected for. Trouble if you put a 50 amp receptacle on a 40 amp breaker. But you could have a 40A socket on 60A breaker.

 

[eprosenx]

Hi guys. I'm new here. Got a model 3 long range rear wheel drive a week ago. (This thing is like driving a spaceship!)

I had an electrician install a 220v 50 amp circuit in my garage for charging. I charged it up last night for the first time and noticed that the charging screen showed it was getting 32/32 amps.

First, if I had a 50 amp circuit installed, why is the model 3 only accepting 32 amps?

Second, I read in another thread that 32 amps is actually ideal for home charging. Is that accurate?

If so, I'll leave things alone and let this set up be as it is.

Thanks much for your help.

Cheers,
Forest

I wrote this guide up to answer basically this exact question:

How Should I Charge My Tesla? – Article625.com

 

[eprosenx]

I wrote this guide up to answer basically this exact question:

How Should I Charge My Tesla? – Article625.com

Some more color: Lots of good advice here already. Since you already have the 14-50 installed I would probably try that to see how it works for you. No time urgency to the upgrade it sounds like.

I also just wrote down some thoughts (which I have shared many times here in the forum) on the actual math comparing a second UMC on a 14-50 to the cost of a Wall Connector:

Tesla Mobile Connector Gen 2 vs Wall Connector – Article625.com

While I installed a Wall Connector on a 60a circuit for my M3LR and I love having it, I would be totally fine on a 14-50 using the UMC (which I also installed as a backup).

 

[F14Scott]

Pretty sure that’s backwards. Violates code to put a higher rated receptacle than the circuit is protected for. Trouble if you put a 50 amp receptacle on a 40 amp breaker. But you could have a 40A socket on 60A breaker.

 

[F14Scott]

If this were true, why have individual breakers at all? One could put all of a house's outlets on the single main 200A breaker and be OK, right?

 

[jmaddr]

If this were true, why have individual breakers at all? One could put all of a house's outlets on the single main 200A breaker and be OK, right?

In all cases, the breaker should be rated for the lowest device in the path of the electrical circuit. Since the 14-50 outlet is rated for 50A, regulations are no more than a 50A breaker. The same holds for if you happened to use 8 gauge or even thinner wire.

The reason is if you plug in a device that happens to pull 60 A, the outlet itself or the wires to the breaker may overheat and melt the receptacle or the wires or both, causing fires. You are allowed to put on a breaker below the rated output (50A), but if you do it's best practice to put a note on the receptacle saying such so that the user does not plug in a device that needs 50A and constant tripping results.

 

[F14Scott]

In all cases, the breaker should be rated for the lowest device in the path of the electrical circuit. Since the 14-50 outlet is rated for 50A, regulations are no more than a 50A breaker. The same holds for if you happened to use 8 gauge or even thinner wire.

The reason is if you plug in a device that happens to pull 60 A, the outlet itself or the wires to the breaker may overheat and melt the receptacle or the wires or both, causing fires. You are allowed to put on a breaker below the rated output (50A), but if you do it's best practice to put a note on the receptacle saying such so that the user does not plug in a device that needs 50A and constant tripping results.

Yes, I agree, completely. My question was rhetorical, but my writing sometimes lacks the inflection that my tone demands. You can't build a 1000 amp system with wrist-thick copper and a breadbox-sized breaker, terminate it at a 15 amp outlet, and call it good. The breaker must protect the entire circuit at the level of the weakest link. In this case, if the NEMA 14-50 outlet is good for 50 amps (40 continuous), the breaker must protect it by tripping at ~50 amps.

Now, if you want to wire a bulletproof system and use a 50 amp breaker for the 14-50 plug temporarily, anticipating installing a bigger outlet and upping the breaker size later, that's fine.