Best Way to Charge

[ucmndd]

"Acceptable" but not to code.

Actually it is perfectly acceptable AND permissible by code.

NEC allows 40 amp breakers on 50 amp receptacles because there are no 40 amp receptacles. It's very common for 14-50s to be wired this way - usually for electric ranges, not plugs meant for EV charging - but fully legit in either situation.

 

[osseckiii]

We usually charge to 80% or 90% on an Oct 2018 LR rear wheel drive Model 3. For a couple recent road trips we maxed out the charge. With the help of the recent 5% software battery boost, our max was 319. Is anyone getting 325? It sucks that driving 80mph on the highway only goes about 260 miles (with aero hubcaps).

 

[David99]

After driving my Tesla for 5 years in different situations and different dwellings I would sum it up to this:

Don't worry too much about doing the 'right thing' when charging. Priority should be that you always have enough energy in your battery to make your daily driving and some extra in case of something coming up. The only battery health related rule I would mention is to stay away from the extreme ends meaning try to stay away from discharging down to 0% and equally don't charge to 100% unless you need it. Neither is causing damage to the battery. It just causes a little more stress and thus degradation on the battery.

I have been monitoring the CAN bus data from my car (data directly from the car's internal sensors) and what I can see is that the car is taking care of the battery really well in any situation. More importantly, it also prevents you from doing anything that would damage the battery. For example you can't charge it too fast, or push it too hard. The car monitors all parameters and sets reasonable limits to keep the battery safe. You really can't do anything that would mess up the battery.

Bottom line: don't worry, focus on enjoying the car and driving it. If in doubt, charge it. There is very little benefit trying to follow procedures to 'baby' the battery and hoping to reduce degradation by 1% over 3 years.

 

[tam-o-shanter]

We usually charge to 80% or 90% on an Oct 2018 LR rear wheel drive Model 3. For a couple recent road trips we maxed out the charge. With the help of the recent 5% software battery boost, our max was 319. Is anyone getting 325? It sucks that driving 80mph on the highway only goes about 260 miles (with aero hubcaps).

I got 323 last Friday AM after last update. LR RWD bought in December. Just turned 5k miles.

 

[dhrivnak]

A 40 amp breaker is also acceptable and perhaps more appropriate for a gen 2 mobile connector.

Yes that will meet code, BUT as a NEMA 14-50 people would expect a 50 amp breaker as at some point someone may plug in an RV or an older Model S connector which would blow the breaker. At Lowes BOTH breakers are 9.51 so why skimp. IF you undersized the wire then you should put in the appropriate socket as well.

 

[Treetop235]

First up, get a 60 amp breaker! You'll charge at 32 amps but you need the 60 amp breaker. Charge rate will be about 28-29 mph. Very satisfactory.

I sent my charging limit to the first hash line or about 50%. Like you, I have minimal driving. I usually charge when I drop to about 80-90 miles on the screen. The energy use graph is a more accurate measure of the energy you have but when not worrying about long distance, I just use the screen number. Takes 2-3 hours to charge again to 150-155. After a while, you'll have your pattern figured out. Good luck.

Agree with 60 amp breaker, if you install with a wall charger, you can charge at 48amps or 43mph. That is what I have.
My daily commute is about 25 miles round trip. I charge to 75% every night, and then use STATS to top to 80% just before I go to work.

I support several offices, so some day I may drive 200 miles. Elon has stated to just keep it plugged in and let the car manage the battery.
Also on his advise, I will charge to 100% a few times a year to keep things in sync.

 

[Dre78]

As already mentioned, average mileage customers will not notice a huge difference in battery degradation. It's beyond 100,000 miles where the differences begin to matter.

Source:

 

[eprosenx]

Yes that will meet code, BUT as a NEMA 14-50 people would expect a 50 amp breaker as at some point someone may plug in an RV or an older Model S connector which would blow the breaker. At Lowes BOTH breakers are 9.51 so why skimp. IF you undersized the wire then you should put in the appropriate socket as well.

I always recommend when wiring new receptacles that folks put in wire gauge sufficient to support 50 amps and the corresponding 50a breaker, but when your intended load is a 32a (continuous) EVSE like the UMC Gen 2, code fully allows you to use a 40a breaker and the corresponding smaller wire. I do agree that it is a bad idea since in the future someone could plug in an RV or more likely a 40a continuous EVSE, but this is how the code is written in the US (2017 NEC).

The only time I recommend a 40a breaker is if there is pre-installed wire that is only good to 40a. While there is no code requirement to do so, I would label the receptacle as such for future owners.

Note that 14-50 receptacles on say 8 AWG romex with 40a breakers are really common for electric ranges/stoves. There is no reason to oversize that wire since there is not really any chance you will need to upsize the circuit later...

Agree with 60 amp breaker, if you install with a wall charger, you can charge at 48amps or 43mph. That is what I have.
My daily commute is about 25 miles round trip. I charge to 75% every night, and then use STATS to top to 80% just before I go to work.

I support several offices, so some day I may drive 200 miles. Elon has stated to just keep it plugged in and let the car manage the battery.
Also on his advise, I will charge to 100% a few times a year to keep things in sync.

DO NOT put a 60a breaker on a NEMA 14-50 receptacle. That is against code.

Feel free to future-proof the wiring and install a larger conductor gauge to support a later upgrade to a Wall Connector, but you need to swap the breaker to 60a later, not at the time of the initial install with the 14-50.

 

[ucmndd]

IF you undersized the wire then you should put in the appropriate socket as well.

The appropriate socket in this case IS a 14-50. There's no such thing as a 40 amp receptacle.

 

[Goodtohave]

People talk of “future proofing” and putting a wall connector on a 100 amp circuit but many of us simply do not have a big enough entrance on our homes for that.

I have a 200amp entrance, can’t use half of ot for my car.

 

[LCR1]

People talk of “future proofing” and putting a wall connector on a 100 amp circuit but many of us simply do not have a big enough entrance on our homes for that.

I have a 200amp entrance, can’t use half of ot for my car.

Future proof what? Who the hell needs 100amps to charge a car? I charged my leaf on 12amp 240v for the longest. I can still charge my car overnight on that, hell, I can charge my car in a few hours on the 40A it has now so I could most certainly charge two cars on that 40A if I ever needed to. People have unrealistic expectations that home charging needs to be done in a few hours, when do they ever sleep?

 

[ucmndd]

I have a 200amp entrance, can’t use half of ot for my car.

Sure you can. Lots and lots of people do.

 

[Rocky_H]

Future proof what?

A second or third electric car. Sometimes the main wiring run to get a circuit connection to the garage location is long. It is well worth getting some extra thick wiring in there, so you can divide it up later to an extra charging point or two for extra EVs.

 

[Daniel in SD]

Actually it is perfectly acceptable AND permissible by code.

NEC allows 40 amp breakers on 50 amp receptacles because there are no 40 amp receptacles. It's very common for 14-50s to be wired this way - usually for electric ranges, not plugs meant for EV charging - but fully legit in either situation.

Yep. I'm wrong. My bad!

 

[eprosenx]

Yep. I'm wrong. My bad!
View attachment 393364

So I should also call out:

My reading of the 2017 NEC is that Table 210.24 only applies to circuits with more than one receptacle on them.

EV Circuits are required to be dedicated with a single receptacle and so that table does not apply at all.

(but yes, code certainly does allow for 40a wire/breakers on a NEMA 14-50 receptacle if your intended load like a UMC Gen 2 only needs 32a continuous which works out to 40a total when factoring the 125% uprating due to continuous load - though I always suggest installing wire and a breaker for 50a)

 

[LCR1]

A second or third electric car. Sometimes the main wiring run to get a circuit connection to the garage location is long. It is well worth getting some extra thick wiring in there, so you can divide it up later to an extra charging point or two for extra EVs.

Just like the rest of my post described you can charge multiple vehicles on 50amps

 

[hcdavis3]

I always recommend when wiring new receptacles that folks put in wire gauge sufficient to support 50 amps and the corresponding 50a breaker, but when your intended load is a 32a (continuous) EVSE like the UMC Gen 2, code fully allows you to use a 40a breaker and the corresponding smaller wire. I do agree that it is a bad idea since in the future someone could plug in an RV or more likely a 40a continuous EVSE, but this is how the code is written in the US (2017 NEC).

The only time I recommend a 40a breaker is if there is pre-installed wire that is only good to 40a. While there is no code requirement to do so, I would label the receptacle as such for future owners.

Note that 14-50 receptacles on say 8 AWG romex with 40a breakers are really common for electric ranges/stoves. There is no reason to oversize that wire since there is not really any chance you will need to upsize the circuit later...



DO NOT put a 60a breaker on a NEMA 14-50 receptacle. That is against code.

Feel free to future-proof the wiring and install a larger conductor gauge to support a later upgrade to a Wall Connector, but you need to swap the breaker to 60a later, not at the time of the initial install with the 14-50.

Is a 60 amp breaker with 6-3 awg wire ok for hard wiring to the Tesla wall charger?

 

[hcdavis3]

Is a 60 amp breaker with 6-3 awg wire ok for hard wiring to the Tesla wall charger?

Currently using a NEMA 14-50 on a 50 amp breaker. Getting a wall charger. Thanks.

 

[destructure00]

Is a 60 amp breaker with 6-3 awg wire ok for hard wiring to the Tesla wall charger?

My understanding is no, due to temperature rating of the sheathed 6/3 Romex. I had this discussion with a few members here and came to the conclusion (after arguing something that I was not understanding correctly) that I needed to replaced my 6/3 Romex with #6 THHN in conduit.

HPWC wiring - neutral as ground in video?

 

[ucmndd]

Is a 60 amp breaker with 6-3 awg wire ok for hard wiring to the Tesla wall charger?

#6 THHN in conduit is fine, but 6/3 romex is only good to 55 amps.