New SR+ owner 50amp ok?

[Wennfred]

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

Read what I wrote, I would have to change out the wires to 6awg, so for now I will leave it alone.

And who said I’m using a 50amp outlet? Going from my 200amp panel through my 40amp breaker directly into my Tesla Wall unit.


Fred

 

[SilverString]

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!

if they are charging using the mobile charger the max draw will be 32 amps with a 14-50 so using the 80% duty cycle rule a 40 amp breaker would be the norm...

 

[SilverString]

Read what I wrote, I would have to change out the wires to 6awg, so for now I will leave it alone.

And who said I’m using a 50amp outlet? Going from my 200amp panel through my 40amp breaker directly into my Tesla Wall unit.


Fred

My experience here is that on matters of wiring you will get a lot of hip shooters quoting this or that trying to scare you, quite often reading a single reply only. Ignore them and be a safe thinking person because you will never convince them once you have any disagreement what-so-ever. There are also a lot of knowledgable members.

 

[Rocky_H]

My experience here is that on matters of wiring you will get a lot of hip shooters quoting this or that trying to scare you, quite often reading a single reply only. Ignore them and be a safe thinking person because you will never convince them once you have any disagreement what-so-ever.

However, most people are just recommending pretty simply with fully complying with code, because you DON'T want to get into some fight with a local inspector who points out you are in violation. Your continued advice to a lot of people to just go ahead and do it against code because "you know it's safe in this case" is just asking for trouble that most people don't want to deal with.

 

[crackers8199]

i set 80% as daily charging because it feels like whenever i go to 90% in colder weather, my regen is limited first thing. starting at 80% solves that issue, and i don't drive enough for it to be a problem.

 

[AdamMacDon]

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!

The car will limit and control both AC and DC fast charging so it won't draw more than it can handle. I've used 60amp Tesla charging stations with my SR+ and all it does is limit your draw to 32 amps. On the topic of 32 amps, even if you had a car with a more powerful onboard charger like a dual motor 3 or an S/X, you will be limited to a 32amp draw because the second gen mobile charger has a 32 amp limit. I believe the old gen was 40 amps, but that was designed for Model S/X that need significantly more juice per kilometer driven.

Just leave the charging slider at 90% and forget about it. Trust me, after a month or two, you'll be baffled as to why you even worried about it for 99% of your driving situations. I used to set it to 70% and try to not drive below 30%, but first I messed up my BMS so my rated range temporarily plummeted, and second, it's a headache and waste of time. Don't do what I did, haha. In my experience, the settings below 90% are mostly for long term storage, where if the car was going to sit for a few weeks, I'd drain it to around 60% or so and leave it on the charger with the slider set to 50%. Like other users have said many times, generally the battery is pretty idiot proof. As long as you aren't charging to 100% and discharging to 2% frequently, it will probably have no issues.

The biggest way to save energy driving is go slower, this is obvious, energy drain increases EXPONENTIALLY with speed. If you went 10kmph (6mph) everywhere you'd probably get a 700 kilometer range (450 miles). Or more. If you're going 160kmph (100mph) you'll see that battery drain like crazy. 200 miles of range at that speed would be lucky. The biggest killer for me living in a Canadian city is not speed but cold. Less relevant in Georgia, but if you ever do a road trip through a cold area, be prepared to lose up to 40% of your range just heating the cabin. Unlike a gas car that always produces waste heat, electric cars have to make it to heat your car, and that energy is coming right from your HV battery. During the summer I find the AC uses a noticeable amount of energy, but nowhere near as crippling as the heat, the worst I saw was about 8% more energy usage on a really hot day in Vegas.

My energy consumption in the spring is about 121wh/km (195wh/mile). Winter I see about 200-250 wh/km consumption (320wh/mile-402wh/mile)

 

[Roman92]

The car will limit and control both AC and DC fast charging so it won't draw more than it can handle. I've used 60amp Tesla charging stations with my SR+ and all it does is limit your draw to 32 amps. On the topic of 32 amps, even if you had a car with a more powerful onboard charger like a dual motor 3 or an S/X, you will be limited to a 32amp draw because the second gen mobile charger has a 32 amp limit. I believe the old gen was 40 amps, but that was designed for Model S/X that need significantly more juice per kilometer driven.

Just leave the charging slider at 90% and forget about it. Trust me, after a month or two, you'll be baffled as to why you even worried about it for 99% of your driving situations. I used to set it to 70% and try to not drive below 30%, but first I messed up my BMS so my rated range temporarily plummeted, and second, it's a headache and waste of time. Don't do what I did, haha. In my experience, the settings below 90% are mostly for long term storage, where if the car was going to sit for a few weeks, I'd drain it to around 60% or so and leave it on the charger with the slider set to 50%. Like other users have said many times, generally the battery is pretty idiot proof. As long as you aren't charging to 100% and discharging to 2% frequently, it will probably have no issues.

The biggest way to save energy driving is go slower, this is obvious, energy drain increases EXPONENTIALLY with speed. If you went 10kmph (6mph) everywhere you'd probably get a 700 kilometer range (450 miles). Or more. If you're going 160kmph (100mph) you'll see that battery drain like crazy. 200 miles of range at that speed would be lucky. The biggest killer for me living in a Canadian city is not speed but cold. Less relevant in Georgia, but if you ever do a road trip through a cold area, be prepared to lose up to 40% of your range just heating the cabin. Unlike a gas car that always produces waste heat, electric cars have to make it to heat your car, and that energy is coming right from your HV battery. During the summer I find the AC uses a noticeable amount of energy, but nowhere near as crippling as the heat, the worst I saw was about 8% more energy usage on a really hot day in Vegas.

My energy consumption in the spring is about 121wh/km (195wh/mile). Winter I see about 200-250 wh/km consumption (320wh/mile-402wh/mile)

Great information! As a first time Tesla owner this is great!! Been looking into it so many years and reading and being on these forums and then when I finally get the car I start loosing my mind!! Thanks again!

 

[AdamMacDon]

Great information! As a first time Tesla owner this is great!! Been looking into it so many years and reading and being on these forums and then when I finally get the car I start loosing my mind!! Thanks again!

Hahaha I remember the exact same build up for me. Enjoy the Tesla, even after just driving the base Model 3 for a year I never want to go back to a gas car, even a nice one like a Mercedes C63 AMG.

 

[SilverString]

However, most people are just recommending pretty simply with fully complying with code, because you DON'T want to get into some fight with a local inspector who points out you are in violation. Your continued advice to a lot of people to just go ahead and do it against code because "you know it's safe in this case" is just asking for trouble that most people don't want to deal with.

Well put. I never knowingly suggest that anyone go against code where there is a code issue. I grew up around EE's and in the electronics world, and I would never suggest anything I know is not safe just to save money. Seeing your posts here you quite clearly have a balanced grasp of electrical and I would guess you are an electrician or engineer, a good one. But I have absolutely zero tolerance for the fear mongering that goes on around electrical wiring, extension cords, and NEMA this and NEC that - a sign of the times.

 

[rdskill]

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

I haven't seen this anywhere either. I just scoured the Owner's Manual (v2020.4 is now downloadable from Tesla) and it seems to me Tesla went out of their way to make no recommendations at all as to how much you should charge your battery.

I even searched for 90 with no hits related to charging and not a thing when I searched for 90%.

Guessing the lawyers were in charge of approving the contents of the manual.

 

[user212_nr]

I haven't seen this anywhere either. I just scoured the Owner's Manual (v2020.4 is now downloadable from Tesla) and it seems to me Tesla went out of their way to make no recommendations at all as to how much you should charge your battery.

I even searched for 90 with no hits related to charging and not a thing when I searched for 90%.

Guessing the lawyers were in charge of approving the contents of the manual.

Its apparently 91% that triggers the warning message. I guess they figure that showing the warning means they don't need to put it in the manual. Big omission though.

 

[rdskill]

Its apparently 91% that triggers the warning message. I guess they figure that showing the warning means they don't need to put it in the manual. Big omission though.

It wasn't the warning I was searching for, but rather the max recommended charging level on a daily basis.

I use TeslaFi and will charge to 90+ when prompted by the app. Otherwise I slow charge it to 50-70 at work (16A) during the week.

The fact a warning is given at 91 vs 90, indicates you are on the threshold. I am sure that the single amp difference is meaningless as it's the high voltage that you are holding the battery at 90% that matters. But the more important voltage isn't displayed.

There are different voltages for bulk voltage, absorbing voltage, floating voltage. We should be told when the battery has hit the upper level of absorption voltage so we know when we are stressing the battery.

In the not so distant past, Li-ion cells could actually flip polarity when run completely flat or overcharged. I wonder if that still applies. I am assuming it does. I'd wish Tesla shared more.

Regardless, I will continue to supercharge less often and slow charge to 70-80 or less, as I am assuming that is still the absorbing voltage stage and take it to 90+ on occasion or when I need the range.

 

[Wennfred]

It wasn't the warning I was searching for, but rather the max recommended charging level on a daily basis.

90%

Fast forward to 1:25 into the video and listen to what Kim has to say:

 

[Wennfred]

Just to let you know, I charged daily to 90% on my SR+ for a full year and stayed at 239-240 mile range. I’ve posted this info on various threads, then came 2020.12.5 I believe and the battery took a 10 mile dump immediately. Sentry & Dashcam went to shït as well.

It was around 17,200 miles where you can see the sudden drop in range.

 

[jbcarioca]

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

Just remember, Fred, that any Tesla can charge from anything from 110/15 upwards. For home use in moderate climates like yours, if your car will sit at least eight hours on charge 203/20 ( that is what I typically get on my, 208/30 connection, shared with a large swimming pool). My Model S P85D would easily go from 10% to 90% overnight, and my Model 3 P does it a little more quickly. There is no need for a larger capacity, so long as you charge overnight.

Now in my 6th year of Tesla driving (including thousands of long distance miles in S70, X90, X100, SP100 and several others I have used many different charging solutions, including 120/20 (a long extension cord from a hotel laundry room, plus innumerable hotel outside plugs beside A/C compressors). After innumerable odd adventures during the 2014/2015 years pre Supercharger coverage I realize almost everyone overestimates what they need at home.

Actually if you have frequency at or above nominal 208V and an output of nominal 30A Or above you’ll be perfectly fine. More is not necessary or even desirable, since a stable lower charge rate has your battery happily snacking away. Finally, when you’ll routinely leave it lugged in when ever you are not driving, you’ll eventually end out leaving your car at ~50 routinely, and change the charge level only when you will drive more that, say, 100 miles the next day.

 

[TomB985]

Actually if you have frequency at or above nominal 208V and an output of nominal 30A Or above you’ll be perfectly fine. More is not necessary or even desirable, since a stable lower charge rate has your battery happily snacking away. Finally, when you’ll routinely leave it lugged in when ever you are not driving, you’ll eventually end out leaving your car at ~50 routinely, and change the charge level only when you will drive more that, say, 100 miles the next day.

I agree with your post, but wanted to point out the efficiency difference with charging rates. The slower you charge, the longer you spend with the car "awake" and wasting energy to keep its systems functioning. When the car falls asleep, the HV battery is disconnected, and you lose virtually nothing from the HV battery in less it needs to wake to charge up the 12 V system again. Mine normally falls asleep after about 30 minutes once charging is complete.

Which means you use considerably more energy charging for 24 hours from a regular household outlet compared to five hours with a 240/32 amp circuit. Energy costs vary, and around here we don't pay that much, so it's not much of a concern. But it could add up for areas with higher rates.

 

[jbcarioca]

I agree with your post, but wanted to point out the efficiency difference with charging rates. The slower you charge, the longer you spend with the car "awake" and wasting energy to keep its systems functioning. When the car falls asleep, the HV battery is disconnected, and you lose virtually nothing from the HV battery in less it needs to wake to charge up the 12 V system again. Mine normally falls asleep after about 30 minutes once charging is complete.

Which means you use considerably more energy charging for 24 hours from a regular household outlet compared to five hours with a 240/32 amp circuit. Energy costs vary, and around here we don't pay that much, so it's not much of a concern. But it could add up for areas with higher rates.

In part I agree. It is quite easy to calculate the relative efficiency of higher voltage vs lower, which is why higher voltage is increasingly desirable as distance rises. However, lower amperage is less inefficient that is higher amperage for a given voltage, so a slower charge rate is slightly more efficient than is a higher charge rate. That is easy to test in a simple example, no instruments required. Using an old Model S or X that can accept 80 amp AC charge it with an HPWC at 80AMP and after a few minutes feel the cable. It will be hot. Then find a place to charge at 208/30 for a few minutes and check the cable temperature. It will not be hot. I did that with my P85D once by coincidence.

However that is not the real energy draw. Two things are Sentry Mode and vehicle awake. Yu can always turn sentry mode off. The car turns off one charging has been established. So long as you don't wake it up, it stays asleep, with only charging circuitry alive. The inefficiency happens when you check charging status on your car, that wakes it up. You'll notice that if you're charging for a while and want to check the status the app waits a few seconds before updating, because it must wake the car up. Eventually, after a couple fo years with Tesla I grew more patient with status checks, most people eventually do.

 

[TomB985]

In part I agree. It is quite easy to calculate the relative efficiency of higher voltage vs lower, which is why higher voltage is increasingly desirable as distance rises. However, lower amperage is less inefficient that is higher amperage for a given voltage, so a slower charge rate is slightly more efficient than is a higher charge rate. That is easy to test in a simple example, no instruments required. Using an old Model S or X that can accept 80 amp AC charge it with an HPWC at 80AMP and after a few minutes feel the cable. It will be hot. Then find a place to charge at 208/30 for a few minutes and check the cable temperature. It will not be hot. I did that with my P85D once by coincidence.

I don't disagree, but this is a fairly small loss IMHO.

However that is not the real energy draw. Two things are Sentry Mode and vehicle awake. Yu can always turn sentry mode off. The car turns off one charging has been established. So long as you don't wake it up, it stays asleep, with only charging circuitry alive. The inefficiency happens when you check charging status on your car, that wakes it up. You'll notice that if you're charging for a while and want to check the status the app waits a few seconds before updating, because it must wake the car up. Eventually, after a couple fo years with Tesla I grew more patient with status checks, most people eventually do.

I don't think this is right. I can tell in my car is asleep because the charge port light is off, screen is powered down, coolant circulating pump isn't running, and both TeslaFi and the Tesla app indicate the car is asleep. None of this happens while charging; the screen powers up right away and the coolant pump is always running. I'm sure some of the charge efficiency difference has to do with stepping up 110 V against the smaller difference of stepping up 240 V, but I don't think the systems power down while charging.

 

[rdskill]

90%

Fast forward to 1:25 into the video and listen to what Kim has to say:

Great Video. Thanks for the link. Very informative. Too bad not a single word of Tesla's recommendation is in the owners manual. wtf eh?

So 80-90 is fine. I wish they would reveal the voltages, but guessing 90 is still well below the highest voltage that would signal a drop to float voltage.

I have to use work (20A) during the week and SC on the weekend to take it up to 90 at last once every weekend instead of once a month.

 

[Rocky_H]

I haven't seen this anywhere either. I just scoured the Owner's Manual (v2020.4 is now downloadable from Tesla) and it seems to me Tesla went out of their way to make no recommendations at all as to how much you should charge your battery.

Yes they do.

Too bad not a single word of Tesla's recommendation is in the owners manual. wtf eh?

Yes they do.

Open up that charging screen in the car. See where the section from 50% to 90% is marked "DAILY"? That IS the recommendation.

The thing is, closer to 50% is healthier for the battery long term, but that would be horribly impractical for people to actually use the car. So you will probably want to pick some level that works well for you. So there it is--officially from Tesla--anywhere in that 50% to 90% range is the recommended daily level. Every person's situation is different, so it's just impossible for them to give one single number that is best. They have told the sales people to say 90%, though, just to get people to shut up and stop asking, but that is a marketing number just so they have one answer to give to everyone. It's not perfect, as indicated by 91% and above giving a warning that it's not healthy and not recommended to use that high a level constantly, so 90% is a bit borderline.

So a lot of people use around 70-80% for regular daily use to find that comfortable balance to be a bit lower than the 90's but still have enough range to use the car.