2019.12.1.1 Supercharger Throttling?

[Dublin 'Eer]

I didn’t charge at home last night so I could swing by a local supercharger this afternoon to see if there was any change to the charging speed on my car. It hasn’t changed with the update, so no faster charge speeds for us who have been throttled.

 

[Mark_T]

BTW What is balancing? It is making all the series battery groups have the same voltage. That can be and is done at any battery state of charge. It is not necessary to arrive at some state of charge to begin the balance process. The battery management system is always seeking to balance the battery.

The aim is to have the cells at both the same state of charge and at the target peak voltage, that can only really be achieved at full charge.

It usually involves the typical two stage lithium charge process, first to get the cells to their peak voltage which would typically be done by the time you get to around 90% of the full charge, then taper off the current gradually while ensuring the voltage does not fall. This is the balance stage and the part that takes the longest.

Eventually you end up at a point where almost no current is needed to maintain target voltage across the cells and the charge can terminate.

 

[Mark_T]

I didn’t charge at home last night so I could swing by a local supercharger this afternoon to see if there was any change to the charging speed on my car. It hasn’t changed with the update, so no faster charge speeds for us who have been throttled.

I'm not surprised, if Tesla have determined that your pack isn't handling the frequent rapid charging well, I can't see that they would suddenly decide to increase the charge rate.

... and there are things they can look for that are easy to monitor to determine the need to restrict rapid charge rates, so it doesn't have to be a simple counter...
.

 

[Feathermerchan]

The aim is to have the cells at both the same state of charge and at the target peak voltage, that can only really be achieved at full charge.

It usually involves the typical two stage lithium charge process, first to get the cells to their peak voltage which would typically be done by the time you get to around 90% of the full charge, then taper off the current gradually while ensuring the voltage does not fall. This is the balance stage and the part that takes the longest.

Eventually you end up at a point where almost no current is needed to maintain target voltage across the cells and the charge can terminate.

Nope. You can balance the cell voltages any time you want. Even if you never charge to 90%. When you charge you will always have one or more cells that reach peak voltage before the others. At that point because you have waited, you must slow down the charge a lot to prevent those peaked cells from going over peak voltage. That costs you time.
ANY time you want you can balance the cell voltages. It is a lot wiser to balance continuously as you charge so that all batteries reach peak voltage together.

 

[Joelgjr]

I don’t know about y’all but my MCU 1 went from unuseable on 8.x to faster than ever on 12.1.1

 

[Mark_T]

Nope. You can balance the cell voltages any time you want. Even if you never charge to 90%. When you charge you will always have one or more cells that reach peak voltage before the others. At that point because you have waited, you must slow down the charge a lot to prevent those peaked cells from going over peak voltage. That costs you time.
ANY time you want you can balance the cell voltages. It is a lot wiser to balance continuously as you charge so that all batteries reach peak voltage together.

Yes, of course you can, and if you look at the better hobby grade lipo chargers for example that is what they do with the small packs used in rc models, but just because you can, doesn’t mean that Tesla do...

What we do know is that when you charge to 100% you definitely go through a balance process and it doesn’t hurt to do that occasionally.

 

[Feathermerchan]

Why would Tesla want to slow down your charging experience by not balancing at all times while charging (and even just when it needs to be done)?

 

[djlott]

You were definitely far below 65kw at 80% state of charge.

Well, says you I guess. But I was there, you were not...but you sound very confident in your statement.

 

[cybergates]

This is what people (including myself) are seeing raised with 2019.12.1.1. Prior to 12.1.1 I would see about 94kw peak on my 2017 S 75. After getting 12.1.1 with preconditioning en route to superchargers I saw 103+ kw multiple times this week. I say 103+ because I was never lower than about 35% SOC and folks seeing up to 110kw were at about 20%, so it may be as high as that. The ramp down is slower too, making the overall charging time shorter. It’s awesome. — Dan

cool can't wait-I'm stuck on 2019.8.5 still :/

 

[Big Earl]

cool can't wait-I'm stuck on 2019.8.5 still :/

Enjoy it for a while longer while they work the bugs out of 12.1

 

[scottrobertson]

I didn't think 75s got throttled that much compared to 90s. At any rate, Tesla throttling is just to protect the pack from an abusive supercharging mix.

They 100% do. My S75 is limited to 83kW

 

[Dublin 'Eer]

They 100% do. My S75 is limited to 83kW

83 kW is exactly where my 2016 S75 tops out as well, and that is just for a brief moment where it touches 83 kW and begins to taper.

 

[Tony8489]

In 2019 I have experienced an unexplained reduction in supercharging speed. Our Tesla travel is highly concentrated in the second quarter. Through last year my max charge rate was 105Kw. Now it's 93kW. This is not due to supercharger variability, as the car was supercharged from a <30% SoC 8x in April 2019 at 5 different chargers and it's consistently at 93Kw.

My S90D has 43,000 miles and overall about 1/3 of charging is at superchargers.

I have searched and do not find a 100 page thread about supercharger throttling. Do we know the 90's are most susceptible?

 

[Big Earl]

In 2019 I have experienced an unexplained reduction in supercharging speed. Our Tesla travel is highly concentrated in the second quarter. Through last year my max charge rate was 105Kw. Now it's 93kW. This is not due to supercharger variability, as the car was supercharged from a <30% SoC 8x in April 2019 at 5 different chargers and it's consistently at 93Kw.

My S90D has 43,000 miles and overall about 1/3 of charging is at superchargers.

I have searched and do not find a 100 page thread about supercharger throttling. Do we know the 90's are most susceptible?

I think all 90s eventually get throttled, unfortunately.

 

[Tony8489]

I found the thread but haven't gotten that far in to it. There was speculation that the throttling kicked in around 40,000 miles, which is exactly when it did for me. Two years ago there were not many 90's with that much mileage but there must be enough now for the pattern to be clearer.

At any rate I'm turning the S90D in next month under the Resale Value Guarantee and plan to order a new 370 mile range Model S in August or September.

 

[Throttled X]

I have a model 2016 X 8000 miles when purchased, 15k now, batteries tested by tesla told they are fine, no problems charging at service center. But when on the road I get on good charge a day 100kw plus then 29kw or lower the rest of trip, I made a YouTube video series to show what happens, search Tesla Throttled or

Is this happening to anyone else?

 

[jplasmd]

It's been discussed before:

Sudden Loss Of Range With 2019.16.x Software

Currently at 614 pages, and 12,272 posts.