Cold weather regen?

[SeminoleFSU]

In one of Tesla's rather boneheaded moves, when VERY cold, the dashed line will not appear, but regen will be completely disabled. It appears that the dash line only appears when regen is limited, but not fully disabled. And I'll also say that the difference between those 2 levels is mind boggling, even the tiniest amount of regen feels a lot different then when there's none at all!

A-Men

 

[WMAC]

Guys, I really, really, didn't intend this to turn into what it has. Why do you need a graphic on your dash to let you know what you know before you get in the car? Now that I know regen doesn't work unless the battery is warm, it isn't a problem - like - at all. Even if I forget that it doesn't work when I get in the car, it takes milliseconds for my brain to realize and remember, oh, yeah, the battery isn't warm yet - hit the brakes. Since it has been cold out, I have pre-warmed the car every time before I get in - except for once, so, turing that energy back to heat isn't completely necessary. After that, I haven't forgotten to do it. There's a lot of nit picking going on in his thread. I just don't understand it. Sorry for the rant, but, many of you sound like you are impossible to please.

 

[Andyw2100]

Guys, I really, really, didn't intend this to turn into what it has. Why do you need a graphic on your dash to let you know what you know before you get in the car? Now that I know regen doesn't work unless the battery is warm, it isn't a problem - like - at all. Even if I forget that it doesn't work when I get in the car, it takes milliseconds for my brain to realize and remember, oh, yeah, the battery isn't warm yet - hit the brakes. Since it has been cold out, I have pre-warmed the car every time before I get in - except for once, so, turing that energy back to heat isn't completely necessary. After that, I haven't forgotten to do it. There's a lot of nit picking going on in his thread. I just don't understand it. Sorry for the rant, but, many of you sound like you are impossible to please.

I don't think wanting software to work well and to provide useful information means that we're hard to please.

I want the graphic on the dash because the situation changes as the battery temperature changes, and I can't tell how that is happening while I am driving. As for "knowing before I get in the car", sure, if the car has been sitting in 0 degree F temperature for 12 hours, I know there's going to be a regen limit. But what about 50 degree F temperature for an hour, after having driven a while? There are plenty of situations where we don't know for sure, one way or the other, before getting in the car if there will be a regen limit or not. There is simply no good reason why we shouldn't be able to see this on the display at all times. If you don't want to use the information, you're free to ignore it. But this is a crucial piece of information that has an effect on how our cars drive. That information should be visually available to us at all times.

 

[WMAC]

I just don't find it crucial. If I let off the accelerator, I know immediately how much regen there is. I don't need a graphic to tell me. The one that is there is sufficient.

 

[Cyclone]

I have a classic, but perhaps other can chime in since this is my first winter with the S. I'm getting lots of limitation around 45 kW these days (starts out with less regen but settles there for a long time). Eventually the dashed line will disappear from 45 kW, but it will still be another 10 - 15 minutes before full regen will go past 45 kW to 60 kW, even though the dashed line is gone. Was this the behavior in 6.2, or is this a bug in 7.x?

Meanwhile, I agree with the posters saying that if it is so cold that regen is disabled, the notice about it or the dashed lines down to 0 kW should remain until the battery warms up.

 

[Andyw2100]

I have a classic, but perhaps other can chime in since this is my first winter with the S. I'm getting lots of limitation around 45 kW these days (starts out with less regen but settles there for a long time). Eventually the dashed line will disappear from 45 kW, but it will still be another 10 - 15 minutes before full regen will go past 45 kW to 60 kW, even though the dashed line is gone. Was this the behavior in 6.2, or is this a bug in 7.x?

Meanwhile, I agree with the posters saying that if it is so cold that regen is disabled, the notice about it or the dashed lines down to 0 kW should remain until the battery warms up.

I have not noticed regen still being limited after the line has disappeared, but to be honest, I have not looked for it. I'll try to pay attention, and see if I can spot that happening.

 

[jerry33]

I have not noticed regen still being limited after the line has disappeared, but to be honest, I have not looked for it. I'll try to pay attention, and see if I can spot that happening.

I believe it does it less with the newer firmware. It used to be quite noticeable, now not so much. And yes, there should be a line (even if it's at 0 kW) when regen is limited or disabled.

 

[Zooomer]

It is a pretty good waste of energy to not regen during cold and force you to use brakes. It would be nothing to transfer regen power to a resistive heater to heat the battery rather than just have you dump it.

 

[jerry33]

It is a pretty good waste of energy to not regen during cold and force you to use brakes. It would be nothing to transfer regen power to a resistive heater to heat the battery rather than just have you dump it.

There are several things that could be done to make the Tesla more efficient, but every mechanical or electronic system you add increases the chance of failure and raises the cost. I'm not saying it's not a good idea, but it's one of those "be careful of what you wish for" items that has the potential to come back and bite you for small gains (for large gains, it's generally worth doing).

 

[AWDtsla]

There are several things that could be done to make the Tesla more efficient, but every mechanical or electronic system you add increases the chance of failure and raises the cost. I'm not saying it's not a good idea, but it's one of those "be careful of what you wish for" items that has the potential to come back and bite you for small gains (for large gains, it's generally worth doing).

Part is already there, doesn't get used.

The software is really really really lacking for winter usability and efficiency. They've just barely got it over the hump so it stays operational.

 

[David99]

If you preheat the cabin for just 20-30 min, the battery temperature gets warm enough to have about 30-40 kW of regen. That's plenty and if you look ahead in traffic, you can get use regen without having to use brakes except to stop at a red light which you always have to. Only when you have the battery completely cold soaked regen is disabled and it takes a while driving to get it to a usable amount. Unfortunately regen doesn't even get used for the cabin heater and battery heater. That could easily be fixed via software and no additional hardware. But any sort of heating from regen power would take significant hardware and changes to the car.