Not having regen after the last software update sucks

[dgpcolorado]

It certainly was limited to 50kW max for years. An update early this year was the first to allow > 50kW regen (as shown on the energy display anyway). This is my experience with my April 2016 S75D. Maybe when they first increased the maximum allowable power they screwed up the temperature relationship.

Not true for my 2014 S-60. The regen display has always gone up to 60 kW on my car and in mild conditions I can peg it at that level when decelerating from high speed, so actual regen may even be higher than that. (Note the 60 kW regen limit on the IC gauge in the picture below.)

Like the OP, I saw a drastic reduction in regen (to zero, with warning message) after 2019.40.2.1 when the battery was cool but not below freezing (2-4ºC). It seemed to improve slightly with 2019.40.2.3; I no longer get regen reduced to zero in cool conditions, although it remains lower than in previous winters. My garage never falls below freezing and tends to be pretty consistent in temperature this time of the year. The regen returns as the battery heater increases the temperature. This is a picture of the battery heater at work 5.6 miles into a trip:

^ Software 2019.40.2.1, car in neutral, HVAC off, battery at 44%; after three miles uphill then two miles of very steep downhill, the regen has increased from zero to about 12 kW.

 

[PWlakewood]

Regen was not limited to 50 kW. Maybe it was on the 75 battery. I certainly got more than 50 kW in my 85 ever since I got it in 2014. The highest I measured was 72 kW. There was a software update that allowed a little more regen in some situations but that was a minor tweak. It was only supposed to help in situations where regen was limited by temperature or charge level.

I've always got more than 50kw in my 75. Seems like somewhere between 60kw and 65kw is normal when regen is not limited

 

[P100D_Me]

I trust why you are saying is coming from a place of knowledge, but when I read a post like this it concerns me

Yes I've been a programmer since the 80's, mostly with embedded systems where flash memory is the primary storage and they handle 1,000's of erase/write cycles in their lifetime, not per month Tesla style.

 

[Battpower]

I may be speaking too soon but with the 40.50 update I literally have not had any limited regen. I live in Washington DC and it’s been cold. The first time I noticed it I had limited regen and parked the car and applied the update. Two hours later, in the evening still, I had no limited regen and thought that was curious. Then this morning, I got in the car after preheating for 20 minutes and no limited regen. I hope this is a permanent update or not a fluke on my part.

For me, critical temp range for battery appears to be between 6 deg C and 8 deg C, allowing time for the considerable mass of battery to warm (and cool after use). Yesterday, (with 40.50.1) at 5 deg C, absolutely zero regen for first 5 mins driving flat / downhill. After 3 mins steep uphill, first amount of minimal regen. For me, no obvious change from 40.20.1.

How are you pre-conditionning and does it show battery heater symbol in the phone app?

 

[Battpower]

How does this regen behavior compare with other EVs?

Not directly comparable, but I can give info for my Renault Zoes (I've owned 2 and look after a third over 4-5 years).

Obviously these are much smaller and lighter, so Potential energy at top of a hill and Kinetic energy at a given speed both less than a Model S. This morning, both cars same outside location over night. Zoe shows 100% charge = 135 miles at 5 deg C (compared with 100% charge = 185 miles at 18 deg C / UK summer. MS Raven LR shows 165 miles, approx 50%.

Driving same route, approx 3 miles down hill then 2 miles up hill & return by same route.

Zoe (40kwh battery): Blended braking (so applying foot break first increases regen to max available before applying friction). Coasting down hill with foot off accelerator, no brake. 9-11 kw regen. Apply brake, regen increase to 15 kw. Max regen under ideal conditions is around 40kw iirc.

MS: One pedal, coasting down hill, zero regen (no green on display). Braking not relevent and if there was regen, applying friction brake would probably reduce regen.

The MS completes the first downhill (at 5 deg C ambient) with no regen available. After 2 mile climb, the first green regen segment just starts to display but minimal braking effect. I suspect the 2nd downhill segment (still having little or no regen) doesn't warm the battery any & it probably even cools a little. By the end of the final 3 mile climb, there is 1 solid green regen segment with little (but noticeable) regen available.

Zoe (22kwh battery): On same route with 100%, allowed less regen. (3-5kw coasting and little or no increase on light application of brake pedal, suggesting no battery capability to accept further charge.

With the larger battery (40kwh) it appeared that Renault allowed regen even at a displayed 100% SOC. Not for long, but long enough!

While considerring differences, the Zoes both increase the range in accordance with the regen from the down hill section. Even with regen active on the Model S, I can go all the way down hill and so far I don't think I have seen any corresponding increase in available range shown.

After 4 winter / summer transitions with the Zoes, summer actual range appears to have stayed fairly consistent at 185 for 40kwr and 70 for 22kwh. Zoes have not been charged above 22kw, and usually at 7kw.

The 40kwh car does 4.5 miles (British!) per kwh summer and 3.5 miles per kwh or a little lower during winter months.

The Zoe's also have heat pumps using the ac in reverse for heating to reduce load on battery in winter.

 

[David99]

It gets worse. Tesla also changed the charging behavior when the battery is cold.

Here is how it used to work: when the battery was very cold, the coolant heater would start to warm up the battery. Once the battery temperature was a little over 0 C it would slowly start to charge. At the temperature increases the charge power would, too. At 8 C the car would charge at 10 kW and the battery heater switched off.

Now the car starts the same way by turning on the battery heater. But the car will not start charging at all until the battery has reached 8 C. Once it has reached that temperature the battery heater turns off and the car starts charging at full 10 kW. I did this test starting with a battery temperature of 2 C and it took 30-40 minutes before it started to charge.

In how many ways does Tesla want to downgrade our cars? This is getting ridiculous.

 

[P100D_Me]

The 40kwh car does 4.5 miles (British!)

Is there a difference between US miles and British miles?

 

[Battpower]

Is there a difference between US miles and British miles?

Just playing it safe! Not possessive or anything like that! Happy to share.

And while sorting that, sorry for my break vs brake in earlier post (before I get picked up for that too!)

 

[PhilDavid]

Has Tesla done something to improve things after 2019.40.50?

It seems something has been tweaked for the better. I had a 20 minute drive yesterday and towards the middle/end of the drive I actually had full regen. Strange how I've always taken regen for granted and realized how much of the magic of driving an EV is because of regen and one pedal driving.

I understand Tesla's desire to preserve the battery and they have the best BMW technology in the industry so hopefully they will reach some middle ground where you can protect the battery and we can have as much regen as safely possible.

Especially when plugged in and activating climate control, preparing the battery for regen would help many of us with lots of short distance drives in the winter and it seems this is what they;ve done with the last software. I need to do some more testing before I can confirm things are better but that seems to be the case.

 

[Battpower]

Has Tesla done something to improve things after 2019.40.50?

It seems something has been tweaked for the better. I had a 20 minute drive yesterday and towards the middle/end of the drive I actually had full regen. Strange how I've always taken regen for granted and realized how much of the magic of driving an EV is because of regen and one pedal driving.

I understand Tesla's desire to preserve the battery and they have the best BMW technology in the industry so hopefully they will reach some middle ground where you can protect the battery and we can have as much regen as safely possible.

Especially when plugged in and activating climate control, preparing the battery for regen would help many of us with lots of short distance drives in the winter and it seems this is what they;ve done with the last software. I need to do some more testing before I can confirm things are better but that seems to be the case.

Any particular software version? I'm still on 40.50.1 but think I saw mention of a newer version.

Around the 5 deg C to 7 deg C battery temp I'm seeing zero or little regen.

After 30 mins at 70mph regen 80% or more and definitely seen unlimited regen with warm battery and low sub 5 deg C ambient.

 

[PhilDavid]

Any particular software version? I'm still on 40.50.1 but think I saw mention of a newer version.

Around the 5 deg C to 7 deg C battery temp I'm seeing zero or little regen.

After 30 mins at 70mph regen 80% or more and definitely seen unlimited regen with warm battery and low sub 5 deg C ambient.

I'm also on 2019.40.50.1.

I'll do some more testing but the regen situation does seem to be improved from what it was prior to the update. I'm happy if they reach som emiddle ground that is better than the almost no regen we had after an update.

 

[serendipitous]

I may be speaking too soon but with the 40.50 update I literally have not had any limited regen. I live in Washington DC and it’s been cold. The first time I noticed it I had limited regen and parked the car and applied the update. Two hours later, in the evening still, I had no limited regen and thought that was curious. Then this morning, I got in the car after preheating for 20 minutes and no limited regen. I hope this is a permanent update or not a fluke on my part.

Mine has been better with 40.50 in the DC area as well, for what it's worth. It seemed to get better on 40.50.1. I only have two data points on 40.50.5 - first day, I'd charged a couple percent before leaving in the morning and had full regen. Second datapoint I did not charge before leaving, air temps were 50 in the morning, cell temps probably a couple degrees less, and I had ~1/3 regen.

 

[hpartsch]

Mine has been better with 40.50 in the DC area as well, for what it's worth. It seemed to get better on 40.50.1. I only have two data points on 40.50.5 - first day, I'd charged a couple percent before leaving in the morning and had full regen. Second datapoint I did not charge before leaving, air temps were 50 in the morning, cell temps probably a couple degrees less, and I had ~1/3 regen.

Just checking -- did they fix the lost regen. Getting tired of the nagging me to update -- but it's worth it for normal regen.

 

[tomas]

Just checking -- did they fix the lost regen. Getting tired of the nagging me to update -- but it's worth it for normal regen.

Hmmm... that’s exactly what I read in DC’s post. Also is my experience. Not back to what it was before, but better. So update.

 

[dgpcolorado]

Just checking -- did they fix the lost regen. Getting tired of the nagging me to update -- but it's worth it for normal regen.

I'm running 2019.40.2.3 and the regen is slightly better than 2019.40.3.1 but way less than last winter. For example, this is a picture of zero regen with my garage and car at about 0ºC:

That's still a lot less regen than in previous winters at that temperature. If it is to protect the battery I don't have a problem with it. The battery can be preheated by charging for an hour or two before leaving home, although that won't work when charging isn't available.

 

[hpartsch]

I'm running 2019.40.2.3 and the regen is slightly better than 2019.40.3.1 but way less than last winter. For example, this is a picture of zero regen with my garage and car at about 0ºC:
View attachment 496424

That's still a lot less regen than in previous winters at that temperature. If it is to protect the battery I don't have a problem with it. The battery can be preheated by charging for an hour or two before leaving home, although that won't work when charging isn't available.

Can you update when you get 2019.40.50.7 or so. Maybe it will be better on that.... I'm going to be holding off until I have proof it's significantly better. My commute is on 15 min and it seems like this "update" would kill my regen.

 

[BigNick]

MCU1 cars aren’t getting 2019.40.50.x yet.

 

[Dan Baldwin]

MCU1 cars aren’t getting 2019.40.50.x yet.

I can confirm that my MCU1 has not received that update yet. I am on 2019.40.2.1

 

[nem3]

I hope this helps some understand at what temps regen is limited. Anything south of 25C you have limited regen. South of 20C you have severely limited regen. South of 10C well, you'll see. Focus on the Max regen and Cell Temp values. Numbers taken from P90DL on 2019.40.2.1.

 

[David99]

I'm rather confused by that. Here is a graph from a drive showing how cell temperature and regen limit are linked. It is taken from a normal drive around town so it gives you a realistic time frame of how long it takes to get to full regen. the 3 degree difference is what it was before the software update. Tesla raised the temperature limits by 3 degrees C.