-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Not having regen after the last software update sucks
- Thread starter PhilDavid
- Start date
Awesome. It would be very helpful if you could let us know what car, year and battery type you have. And most importantly, what software version you are on.
dark cloud
Active Member
Thanks for the info David.
are you driving and using regen to warm the pack up to get these data points?
Not arguing with your data, as I have none, but seat of pants observations tells me it feels like a lot more than a 3 degree C difference: I would have guessed 10 degrees.
Thanks for posting the data!
What is the X-axis of that graph? Is that kW or percentage of full regen?
Sorry, I forgot the label. Yes X-axis is regen power limit in kW set by the BMS.
Thanks!
I thought max regen was limited to 50 kW and didn't realize max regen goes up to 100 kW!
That explains why I feel such a big difference when driving with the barely available regen after a recent software update.
I know 3 degrees doesn't seem like a lot but what counts is how much time it takes to get the battery 3 degrees warmer and have the same regen. Here is a graph of the data I captured before I made the software "upgrade". It took a little over 7 minutes of normal driving to warm the battery up 3 degree C to reach the same regen level. If your commute is 20 min, that's 1/3 of the time. But what makes things worse is that you also start with much lower regen when you get in the car, so the overall loss of power you can get back is significant.
The are three values graphed out. The average cell temperature, the max regen power set by the BMS, and the maximum charge rate allowed by the BMS. It is interesting that the BMS seems to allow a slightly higher regen amount than charge power. I guess it is due to the fact that regen will only last for a short amount of time, while charging would be continuous. BTW, this test was done at 30-35% battery level so the state of charge was definitely not in any way a limiting factor.
x-axis is time in minutes, y-axis (left) is power in kW, y-axis (right) is battery temperature in Celsius.
I would so pay extra for a super-capacitor retrofit that would always allow full regen! 
Would be super useful for people like me with very short drives. Most of my drives are around 15-30 minutes. Seems like the worse case for regen with the current changes.
Would be super useful for people like me with very short drives. Most of my drives are around 15-30 minutes. Seems like the worse case for regen with the current changes.
The regen limit still goes up to 100 kW even after the update. The highest regen power I have ever been able to get was 72 kW for a few seconds when letting go of the pedal suddenly while going 100 mph. At normal freeway speeds (75 mph) you get no more than 60 kW regen. The BMS calculates all the way up to 100 kW, but in reality you will never get that much. No Tesla regens at 100 kW*. Once the regen limit is at 60-64 kW you won't feel any restriction any more. Regen feels normal.
*Jason Hughes modified one of his Model S to regen at 100 kW. I wish he would make that available as a software patch LOL
PWlakewood
Active Member
So besides the regen thing going on I noticed a weird behavior the last 3 days. I park outside at work and usually lose 3 to 4 miles range during the day and lately its only dropped by 1 mile. Temperatures have been in the high 20's up to low 40's. I haven't changed any settings.
Same everything as OP. Except I just tried to pay more attention to regen while driving and I think it IS a little weaker than before. It is hard to tell.
dark cloud
Active Member
I trust why you are saying is coming from a place of knowledge, but when I read a post like this it concerns me
AP1 ONLY Please -- life after 2018.50.6
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.
hacer
Active Member
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.
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.
