New SR+ owner 50amp ok?

[Roman92]

Hey guys new sr+ owner here pick up tomorrow been waiting long time for this. My question is I know the on board charger for my car is less then long range. So is it ok to still use a 50amp breaker on the 14-50 plug? I have friends who have Tesla’s and would like to have that option for them when they come over to get the full charging benefit for there cars? Also with all new updates and warmer weather(live in GA) what should I shoot for for a good wh/mile rating (specifically for st+)?

and will take any tips on chairing habits for battery health. Was hoping to do 90- and not go below 30-40 daily.

thanks for all the help!!
Cheers!

 

[user212_nr]

The breaker is for the protection of the wire, the umc, and the outlet, and also for protection from short-circuits. The Tesla does not need to be protected by a breaker sized to its exact charge capacity.

The SR+ can handle a much larger current that 50A when it is used for DC supercharging, and it has its own mechanism of limiting the current to what it need/wants.

Tips on charging habits, keep plugged in as a habit, set to 80-85% charge limit unless doing a long trip. Better to go down to 20 (or 25-35 based on your numbers) than to charge to 90 every day.

As to wh/mile, not sure why you would seek to target that (environmental reasons, cost?). Driving slower will increase your range and lower your wh/mile if you need.

 

[Roman92]

The breaker is for the protection of the wire, the umc, and the outlet, and also for protection from short-circuits. The Tesla does not need to be protected by a breaker sized to its exact charge capacity.

The SR+ can handle a much larger current that 50A when it is used for DC supercharging, and it has its own mechanism of limiting the current to what it need/wants.

Tips on charging habits, keep plugged in as a habit, set to 80-85% charge limit unless doing a long trip. Better to go down to 20 (or 25-35 based on your numbers) than to charge to 90 every day.

As to wh/mile, not sure why you would seek to target that (environmental reasons, cost?). Driving slower will increase your range and lower your wh/mile if you need.

No specific reason was just curious to what everyone was getting. But thank you for your help!!

 

[Teedub21]

Tesla recommends plugging in whenever you can and setting max charge to 90%. Seems to work for a lot of people.

 

[CertLive]

Tesla recommends plugging in whenever you can and setting max charge to 90%. Seems to work for a lot of people.

I think in terms of charging and BMS why have any other reason not to go by what Tesla say on this. Its a superior system to all others at the moment.

 

[user212_nr]

Tesla recommends plugging in whenever you can and setting max charge to 90%. Seems to work for a lot of people.

When I set to 90% daily charging, I get a message telling me not to do regularly.

 

[Teedub21]

When I set to 90% daily charging, I get a message telling me not to do regularly.

Never seen or heard of that. Your car may be one of a kind. I’ve followed this charging schedule for the better part of a year whether I drive 100 miles or 1 mile and have never seen that message.

 

[bedoig]

You get that message if you repeatedly charge to over 90%. I'd guess the slider is actually at like 91% or something.

 

[acarney]

I have my SR+ charging with the included mobile cord on a NEMA 14-50 and it works just fine. It’ll pull a max of 32 amp which is ~64% of the circuit max capacity, which gives a nice buffer for safety. Your friends will only get a max of 40 amp (9.6kW) because you don’t want to use more than 80% of a circuit continuously.

I only drive approximately 10 miles or so a day and charge to 75% a day (unless needing to go on a trip). I’m at 6,000 miles and about 0.8% battery degradation (I’ve lost just under 2 miles of max range).

 

[Sameer]

Hey guys new sr+ owner here pick up tomorrow been waiting long time for this. My question is I know the on board charger for my car is less then long range. So is it ok to still use a 50amp breaker on the 14-50 plug? I have friends who have Tesla’s and would like to have that option for them when they come over to get the full charging benefit for there cars? Also with all new updates and warmer weather(live in GA) what should I shoot for for a good wh/mile rating (specifically for st+)?

and will take any tips on chairing habits for battery health. Was hoping to do 90- and not go below 30-40 daily.

thanks for all the help!!
Cheers!

A 40 amp circuit breaker will do the job, as SR+ charges max at 32amps using 220-240volts.

 

[UncleCreepy]

That would be against code. If you have a Nema 14-50 outlet installed, the breaker size must be 50A.

 

[Ritz]

Never seen or heard of that. Your car may be one of a kind. I’ve followed this charging schedule for the better part of a year whether I drive 100 miles or 1 mile and have never seen that message.

I've seen that message as well if I plug in when I'm already at 80-90% capacity. I've fallen into a groove where I let it discharge down to 45-50% and then plug in to charge back to 85%. Haven't seen the message since.

I'm using 14-50 outlet on 50A circuit (like it should be) just fine. It charges at about 30 miles of range per hour.

Best,

 

[Rocky_H]

That would be against code. If you have a Nema 14-50 outlet installed, the breaker size must be 50A.

That's not true. It is nice to use a 50A breaker for that, as it's completely foolproof, but there is an allowed exception for 40A circuits, since there is no defined 40A outlet type. So NEC allows 14-50 or 6-50 outlets on 40A circuits if the device to be plugged into it follows the proper rules for a 40A circuit. Like many ovens are 40A circuits with 14-50 outlets. Since the Tesla UMC is for max 32A continuous, it also follows that rule and can be used under that exception.

And yes, @user212_nr if you're getting that warning, the slider must be just barely over the 90% mark.

 

[UncleCreepy]

That's not true.

I stand corrected, you are right. It makes no sense to me, but then again, it doesn't have to.

 

[Rocky_H]

I stand corrected, you are right. It makes no sense to me, but then again, it doesn't have to.

I will certainly agree that it is just better practice to go ahead and size it properly as a full 50A circuit just for unknown future use. Someone may sell the house, and that outlet on the garage wall isn't marked that it was only on a 40A and the next owners just plug stuff in, thinking it's a 50A, etc. etc. But yes, technically, it does comply with code to do it as a 40A because the Tesla UMC is a 40A rated appliance.

 

[Roman92]

Thanks for the help guys just went ahead and installed the 50 amp! I’m through the roof with this car. It’s pretty amazing!!

 

[Wennfred]

When I set to 90% daily charging, I get a message telling me not to do regularly.

Would be cool to see a picture of this on the screen, SR+, been charging at 90% for a year now, never seen that message.

Fred

 

[Wennfred]

A 40 amp circuit breaker will do the job, as SR+ charges max at 32amps using 220-240volts.

That’s where I’m at, 40amps, but will have to change it to 60amps to charge the Model Y.

*** I thought it over, I will just keep it at the current 40amps breaker for the model Y, will just take a little longer to charge but no rush. Going to 60amps means I would have to replace the wiring to 6 awg. Will leave it alone.

Fred

 

[dhrivnak]

Hey guys new sr+ owner here pick up tomorrow been waiting long time for this. My question is I know the on board charger for my car is less then long range. So is it ok to still use a 50amp breaker on the 14-50 plug? I have friends who have Tesla’s and would like to have that option for them when they come over to get the full charging benefit for there cars? Also with all new updates and warmer weather(live in GA) what should I shoot for for a good wh/mile rating (specifically for st+)?

and will take any tips on chairing habits for battery health. Was hoping to do 90- and not go below 30-40 daily.

thanks for all the help!!
Cheers!

Absolutely but the reality is the mobile connector will only pull 32 amps. But a NEMA 14-50 is what I have installed for all my electric vehicles.

 

[u3b3rg33k]

you can't put a 60A breaker on a 50A outlet/wire. that's definitely not allowed.

That’s where I’m at, 40amps, but will have to change it to 60amps to charge the Model Y.

*** I thought it over, I will just keep it at the current 40amps breaker for the model Y, will just take a little longer to charge but no rush. Going to 60amps means I would have to replace the wiring to 6 awg. Will leave it alone.

Fred