Impact of cold on range, performance, battery life?

[Mike_Schlechter]

At night I leave my Model S plugged in on the normal setting, in an insulated garage. During the day the car sits in a lot at a train station, totally exposed to the elements. What I've had almost every evening is limited regen due to cold.

Is leaving the car cold like this bad for the battery in the long run? I've certainly noticed the lack of regen as I leave the station.

 

[Doug_G]

No, the cold isn't a big problem for the battery. The car knows how to keep it safe - that's why the regen and power is limited until its warmed up.

 

[Mike_Schlechter]

I'm having an adjustment issue mentally I suppose. I've gotten used to no brake driving and then I leave my train station and have basically no regen. It is a little disconcerting at first. With regen limited this sucker really rolls, especially down hills. I suppose there is no way to keep the regen and dump the energy as heat, for instance.

Oh well, I'll deal. No matter what, this thing is still so much fun to drive. My older brother took it for the afternoon yesterday and put a deposit on an X last night. He needs the SUV.

 

[jerry33]

I'm having an adjustment issue mentally I suppose. I've gotten used to no brake driving and then I leave my train station and have basically no regen. It is a little disconcerting at first. With regen limited this sucker really rolls, especially down hills. I suppose there is no way to keep the regen and dump the energy as heat, for instance.

I'd like an option setting for one of the steering wheel buttons to be able to limit regen on demand. That should increase range because regen takes the kinetic energy and turns it into electricity and heat. Limited regen turns the kinetic energy into motion (as you've discovered). Of course, when you actually need to slow down quickly, then regen is more efficient than friction braking, but in general the less regen you use, the greater your range is going to be. Of course you can accomplish the same thing by keeping the indicator on the neutral line, but that requires an educated foot and some concentration that would be better used for other things. (I wasn't able in the short time of the Get Amped drive to determine how hard training your foot would be.) A button would be instantaneous and require less driver attention to accomplish the same job.

 

[EarlyAdopter]

I suppose there is no way to keep the regen and dump the energy as heat, for instance.

There is: the friction brakes. Tesla should program the car to apply the friction brakes ever so slightly when you lift off the accelerator in cold weather no-regen mode to emulate the behavior of regen. Keep it consistent. No surprises.

 

[Electroman]

Actually there is another option that might be even better : do not limit regen in cold weather, but instead of feeding the regenerated power to the battery, it can be fed to a resistive element that can heat the battery quickly to the required temperature. Or if that gets complex to engineer the heat can be used to supplement cabin heating or simply thrown away.

The end result is you get consistent behavior.

 

[mknox]

Actually there is another option that might be even better : do not limit regen in cold weather, but instead of feeding the regenerated power to the battery, it can be fed to a resistive element that can heat the battery quickly to the required temperature. Or if that gets complex to engineer the heat can be used to supplement cabin heating or simply thrown away.

This was discussed, and the consensus is that there is just too much energy to dissipate that quickly.

 

[FVO]

Actually there is another option that might be even better : do not limit regen in cold weather, but instead of feeding the regenerated power to the battery, it can be fed to a resistive element that can heat the battery quickly to the required temperature. Or if that gets complex to engineer the heat can be used to supplement cabin heating or simply thrown away.

The end result is you get consistent behavior.

I totaly agree with you!! That way it's better for the battery, they dont have to modify the brakes and you'l get faster a warm cabin.

 

[Johan]

I totaly agree with you!! That way it's better for the battery, they dont have to modify the brakes and you'l get faster a warm cabin.

An up to 60kW burst of regen is very hard to handle. Even just 10kW is a lot. You'd have ti have some pretty thick wiring just for that, and the resistor would be HUGHE.

 

[EcoHeliGuy]

An up to 60kW burst of regen is very hard to handle. Even just 10kW is a lot. You'd have ti have some pretty thick wiring just for that, and the resistor would be HUGHE.

You can't stuff an elephant through a mouse hole.

the average A/C cooled house uses 10 kWh a day, so they are wanting to put the energy draw of six houses through cold batteries? Ouch.

 

[PRJIM]

This is more or less a safety issue. The bigger factor should be trying to emulate the feel of regen regardless of weather conditions. Being able to use regen energy should be a secondary issue.

 

[Doug_G]

With my current usage and cold weather I rarely get full regeneration power. I have just a little in the morning, and it improves by the time I get to work.

I've only driven the Roadster in regen-limiting cold half a dozen times, and I'm not used to it (partly because it has to be a lot colder, partly because I don't winter drive it). When the Roadster cuts regen it gives me a real "whee!!!" sensation. Model S not so much; it's more predictable, and it's easier to see exactly where it's at because it's right there on the speedometer.

Frankly it's not an issue for me; I have had the car just a few days yet have already fully adapted to it.

 

[wycolo]

Brand fresh ModelS so probably latest software. Fully warmed up regen is nice, almost as strong as Roadster. Lightly press the brake & regen doubles. Very nice indeed.
--

 

[JRP3]

There is: the friction brakes. Tesla should program the car to apply the friction brakes ever so slightly when you lift off the accelerator in cold weather no-regen mode to emulate the behavior of regen. Keep it consistent. No surprises.

This is exactly what I've been advocating.

 

[Doug_G]

Brand fresh ModelS so probably latest software. Fully warmed up regen is nice, almost as strong as Roadster. Lightly press the brake & regen doubles. Very nice indeed.
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Yeah, is it just me or did the regen get significantly stronger since the first Get Amped drives?

 

[montgom626]

There is: the friction brakes. Tesla should program the car to apply the friction brakes ever so slightly when you lift off the accelerator in cold weather no-regen mode to emulate the behavior of regen. Keep it consistent. No surprises.

I would have to say no to this idea. I like to coast and friction brakes would "hurt" my coasting with no advantage to me. Regen is fine, friction brake without regen, not so fine (for me only)

 

[JRP3]

The same pedal position you use for coasting with regen would also keep the brakes from engaging when regen is disabled or low. In other words the car behaves the same way.

 

[GSP]

The same pedal position you use for coasting with regen would also keep the brakes from engaging when regen is disabled or low. In other words the car behaves the same way.

It would be good if it was easy to find and hold that pedal position, and without looking at the dashboard kW meter.

GSP

 

[mknox]

I found with my limited test drive experience that I was "jerking" the car a lot due to my ICE habit of lifting my foot completely off the accelerator to "coast". I am wondering if Tesla could add a user option to either select re-gen as it is now, or to move it entirely to the brake pedal? (i.e. foot off the "gas" and you coast, lightly press the brake and re-gen begins followed by friction braking the harder you press).

I would probably opt for brake only re-gen, especially in the winter when I'd be concerned about accidentally applying too much re-gen to the rear wheels in slippery conditions.

 

[jerry33]

I found with my limited test drive experience that I was "jerking" the car a lot due to my ICE habit of lifting my foot completely off the accelerator to "coast". I am wondering if Tesla could add a user option to either select re-gen as it is now, or to move it entirely to the brake pedal? (i.e. foot off the "gas" and you coast, lightly press the brake and re-gen begins followed by friction braking the harder you press).

I can't see them moving regen to the brake pedal. It makes the system incredibly complex and is very hard to get right so that everyone will be happy. The Toyota system is pretty good (after 16 years) and people still complain about it.

Training your foot to not come all the way up is really the correct answer, in my opinion. I'm pretty sure it will take me awhile to master that aspect as well.

I too would like a pedal "detent" on zero (no regen, no power use) like GSP suggests. Besides the obvious, it would make training your foot much easier.