Lost all regen (again).

[Dangerous Fish]

Yeah, many thanks for your replies. From Teslafi I think it's clear that the battery thinks it is cold (no regen, constant battery heating), so I'm guessing a thermistor failure(s).

I'm booked in for a service now anyway, so hopefully it will get resolved. I'm just a bit concerned that any further driving could overheat the battery enough to reduce its life. Unless it's a heat pump fault and it is genuinely sucking the battery temperature down and dumping the excess heat to the outside.

I'm pretty sure it's a failsafe system and other sensors will kick in before any damage is caused. There is no way the BMS will allow the battery to get hot enough to cause damage. If you are really worried, put it into track mode as at least that will give you an indication of temperatures on the graphic, although there is some evidence to suggest that it's indicating motor/drive unit temperatures than just pure cell temperatures.

I seem to remember the UP car which went up Pikes Peak had a sensor failure during it's race day run which initially looked like a cooling failure but turned out to be a sensor failure. The battery graphic suddenly turned red and power was limited to protect the battery even though there was actually nothing wrong with the cooling system.

 

[15Peter20]

I'm pretty sure it's a failsafe system and other sensors will kick in before any damage is caused. There is no way the BMS will allow the battery to get hot enough to cause damage. If you are really worried, put it into track mode as at least that will give you an indication of temperatures on the graphic, although there is some evidence to suggest that it's indicating motor/drive unit temperatures than just pure cell temperatures.

I seem to remember the UP car which went up Pikes Peak had a sensor failure during it's race day run which initially looked like a cooling failure but turned out to be a sensor failure. The battery graphic suddenly turned red and power was limited to protect the battery even though there was actually nothing wrong with the cooling system.

I’m a mere LR + PB, so there’s no track mode unfortunately.

Bloody thing has fixed itself! I just drove home from work, 100% regen showing on the power bar. Plugged in to the wall connector and it is now increasing the SoC. I did hassle the SC to take a remote peek as a priority, so will ask whether they changed anything remotely. Either way, it needs looking at.

I really wonder whether the heat pump is the cause. The previous two occasions when something similar happened was after I briefly camped in the car on cold winter’s days.

Thanks again for the knowledgeable feedback, much appreciated.

It seems this problem is a pretty rare occurrence at least amongst TMCers which is good.

 

[Tigermad]

I’m a mere LR + PB, so there’s no track mode unfortunately.

Bloody thing has fixed itself! I just drove home from work, 100% regen showing on the power bar. Plugged in to the wall connector and it is now increasing the SoC. I did hassle the SC to take a remote peek as a priority, so will ask whether they changed anything remotely. Either way, it needs looking at.

I really wonder whether the heat pump is the cause. The previous two occasions when something similar happened was after I briefly camped in the car on cold winter’s days.

Thanks again for the knowledgeable feedback, much appreciated.

It seems this problem is a pretty rare occurrence at least amongst TMCers which is good.

Hi. I’ve only had my Tesla SR+ a week. How can you tell you have 100 percent regen?

 

[Mrklaw]

Hi. I’ve only had my Tesla SR+ a week. How can you tell you have 100 percent regen?

on the top of the screen above your car there is a thin line - moves to the right in grey (?) when accelerating and using energy, and to the left in green when regenerating. On that left hand side if your battery is full, or cold, or both, you get a series of dots starting from the left - the more dots, the less regen you have



(I’d like it to be a bit thicker so its easier to notice)

 

[Adopado]

Hi. I’ve only had my Tesla SR+ a week. How can you tell you have 100 percent regen?

There's a thin horizontal line near the top of the visualisations area of the screen just underneath the speed readout. If it has dots on the left then there is some degree of regen restriction. The same line that shows if you are using power or are generating.

 

[Tigermad]

on the top of the screen above your car there is a thin line - moves to the right in grey (?) when accelerating and using energy, and to the left in green when regenerating. On that left hand side if your battery is full, or cold, or both, you get a series of dots starting from the left - the more dots, the less regen you have



(I’d like it to be a bit thicker so its easier to notice)

Thanks. I also found this guide which explains quite well

Why does my regenerative braking on my Tesla Model 3 sometimes become unavailable even though the battery is half full?

Answer (1 of 7): A2A — Ronald Redlinski —Thanks for asking the question! ^ Tesla Motors Club — Model 3 & Y. This picture is an EXTREME example of a car that has been left out in bitter cold for a long time. ~~~~ Q. Why does my regenerative braking on my Tesla Model 3 sometimes become unavailab...

www.quora.com

 

[15Peter20]

Yeah, it's very cold-sensitive and it can take many miles to come in fully when the ambient temp is near or below freezing.

Preconditioning, even for a few minutes, is a big help and reduces the time/miles before full or near-full regen is available.

Navigating to a SuC will normally trigger battery heating and hence increase available regen (if the SuC is within half an hour or so of your present position).

 

[Adopado]

Thanks. I also found this guide which explains quite well

Why does my regenerative braking on my Tesla Model 3 sometimes become unavailable even though the battery is half full?

Answer (1 of 7): A2A — Ronald Redlinski —Thanks for asking the question! ^ Tesla Motors Club — Model 3 & Y. This picture is an EXTREME example of a car that has been left out in bitter cold for a long time. ~~~~ Q. Why does my regenerative braking on my Tesla Model 3 sometimes become unavailab...

www.quora.com

What? On Quora? I can't think I've ever put "Quora" and "explains quite well" in the same sentence! (The problem is you may actually get some accurate info once in a blue moon but then you're lulled into a false belief that this is handy and reliable information resource ... it isn't ...beware! )

 

[Tigermad]

What? On Quora? I can't think I've ever put "Quora" and "explains quite well" in the same sentence! (The problem is you may actually get some accurate info once in a blue moon but then you're lulled into a false belief that this is handy and reliable information resource ... it isn't ...beware! )

Thanks. The info on this looks ok to me and appears correct to what I have seen elsewhere

 

[15Peter20]

So the car went in to be checked out and was initially diagnosed as needing a new HV battery, but shortly before fitting the battery a software patch was installed instead which, apparently should fix this problem.

Fingers crossed.