Forums

Can one of you old guys fix my memory on regen?

Can one of you old guys fix my memory on regen?

Last winter, I thought I remember that after 15-20minutes of driving, my regen was full again at 60-70% SOC. But this winter, I drive 40 minutes on the highway, and still a few dots away from full regen.
How long do you need to drive to get full regen back when starting without the snowflake? This year, and if you remember, last year? I don't think it's any colder this year than last.

Pg3ibew | 2019年12月15日

Weather. Weather weather.

derotam | 2019年12月15日

It all depends on the temperature of the battery and how fast it can warm it up based on the current weather. There is no set number as there are too many variables.

derotam | 2019年12月15日

And I'm not old. :)

FISHEV | 2019年12月15日

"But this winter, I drive 40 minutes on the highway, and still a few dots away from full regen."

I hit the freeway pretty quickly from the house and it takes about 40 minutes at 65 mph for me to regain full regen on cool 40F days with blue cold battery warning on.

Pg3ibew | 2019年12月15日

Weather.

TeslaTap.com | 2019年12月15日

"Can one of you old guys fix my memory on regen?"

Move to a warmer climate :)

kevin_rf | 2019年12月15日

Nah, 45+ mile each way highway commute. Last winter I was arriving with most of the Regen dots. The new scheduled departure helps some if you are leaving close to six am. Bumping up the charge level fifteen minutes before you leave also helps.

Frank99 | 2019年12月15日

There's a snowflake icon? Never seen it.
;)

pjwheeler83 | 2019年12月15日

Current temperatures here in Michigan are getting to be below 30. My SR+ can easily take 40-50 miles of highway driving before full regen is available or even more if below 20. Cold soaked battery regardless of SOC has ZERO regen.

ADinM3 | 2019年12月16日

@VolleyBall, I had been wondering the same thing lately, but I think I have an explanation.

1) Our memories are indeed failing us.
2) Variability due to weather is hard to pin down.
3) (my theory), Regen has been increased since last winter. As a result, there are now more conditions where Regen may be limited today with increased Regen versus previous. This is actually a good thing in my mind.
4) Theoretically, they may have changed battery limits or improved efficiencies such that there is less waste heat to warm the battery but this one I only include for completeness, not that I think there is any merit to this one.

The reason I was similarly thinking about this is because I am seeing conditions where I see no dots while normal driving, but they appear under Regen or under harder acceleration. The Regen dots don't surprise me, but I don't remember the acceleration (black) dots coming and going as I touch the accelerator. Maybe it was away there, but I sure don't remember it and suspect it is a result of the performance tweaks and a tweak in UI presentation. Just surprised the dots are a function of pedal position unlike for Regen.

syclone | 2019年12月17日

The fact is that Tesla's battery management software has changed appreciably in the past year. My car (LR-RWD) was delivered in July 2018. This is the car's 2nd winter coming up. Last year there were no warnings about temperature related regen limits, no snowflakes on the display. The only regen warning came up when the battery was close to 100% charge. Somehow, I managed to survive.

kevin_rf | 2019年12月17日

I definitely saw snowflakes last winter.

teslamazing | 2019年12月17日

Helpful hack:

If you charge at home and are not worried about range, just set NAV to the closest supercharger while you drive. I noticed that battery pre-conditioning gives you 100% regen.

Pg3ibew | 2019年12月17日

@teslamazing, doesnt pre-conditioning use battery life. Seens counter intuitive.
Regen gives you added battery. While pre condition uses battery? No?

teslamazing | 2019年12月17日

@pg3 correct. Shoulda clarified more. If you want regen for braking purposes* and dont care for range, battery.

Pg3ibew | 2019年12月17日

Teslamazing, thanks. I love the regen for the braking purposes. I try to pay attention to the car. Living in NYC, we have some really cold days and warm days.
I notice, if pay close enough attention to the regen bars on the screen, I can still get away with one pedal driving.

Pg3ibew | 2019年12月17日

I have my model 3 for 60 days now. It has almost become a challennge to NOT TOUCH the brake pedal during a drive.

teslamazing | 2019年12月17日

@pg3 it’s like a game trying to use regen as much as possible vs hitting the brakes. One pedal driving is great. A win win.

derotam | 2019年12月17日

pre-conditioning while driving on the highway is pointless, it won't do anything. You have to be going less than I'll just say probably 30 max for any effect but even then it would be negligible.

Personally I think battery pre-conditioning has very limited real use cases where it would really make a noticeable difference.

teslamazing | 2019年12月17日

Ahh you read my mind.

derotam | 2019年12月17日

@teslamazing: The real game is trying to coast as much as possible with out using brakes OR regen...and not pissing off the person behind you.

teslamazing | 2019年12月17日

@dero if you referring to my comment about the hack, it would be useful in city streets, highway a definite no.

teslamazing | 2019年12月17日

“ trying to coast as much as possible with out using brakes OR regen” is this with regen off/winter regen ? Lol

Pg3ibew | 2019年12月17日

@tesalmazing, yes!!! I think we are on the same page.

derotam | 2019年12月17日

Even in city streets I don't really see a real use case. If you are going that slow even with full regen capable, you don't have full regen available to use, it is a curve based on speed. Now, using battery pre-conditioning while driving slow in order to gain regen capability because you have ZERO capability due to the battery being cold...then I can see that...BUT...I would only see that as reasonable if you werent able to plan for your departure and change your charging schedule in order to have charging stop right before you leave.

Using charging time to ensure a warm battery is a much better way to ensure regen capability...unless you couldn't predict a sudden departure.

derotam | 2019年12月17日

Nope, coasting with regen on standard by just modulating the accelerator pedal in order to zero out power usage/gain.

teslamazing | 2019年12月17日

True. I guess my case would be if you weren’t starting from home to begin with.

teslamazing | 2019年12月17日

@dero next level shit.

derotam | 2019年12月17日

Yes, that would be a reasonable use case.

Now the question of how much it will really help you and in what time frame is an open question. I am working on getting test data to correlate battery temperature vs amount of available regen but I won't have that for a while. I do know that full regen capability is at a battery temp of approx 18C .

rdh37 | 2019年12月17日

Last year I almost never got the regen limited message. This year so far I am getting it fairly consistently when starting out of an approximately 50 degree garage with ambient temp being around 30 and turning on the cabin heat about 15 minutes prior to departure. However, I have not noticed appreciable regen loss when actually braking. I am still able to use 1 pedal driving. The message turns off about 50% of the time during my 13 mile on congested hwy commute. As long as I have most of my regen available I am fine. As it gets colder I plan on starting preconditioning about 30 minutes before leaving. Hope this helps.

cmh95628 | 2019年12月17日

If only Tesla would invest in a company like Maxwell that makes Super Capacitors so we don't have to be limited on regen when the battery is cold soaked... /s

And I am happy to be an old guy...