Regeneration not available error message

V

victor_2019

Active Member
Yesterday when driving the car I would get the "regeneration not available, battery fully charged" message pop up every time I let off the acceleration, but my battery was around 85% and the car was definitely regenerating.

The message went away after about 30 minutes.
It was around -13C at the time.
The car was otherwise driving fine.

Is there any official link between this message and battery temperature?

It's been cold here in Montreal for a long time now and it's the first time I see this message pop up.

But the car is definitely behaving weird when the temperature is below -15 or so, I suspect an electronic problem. Lots of things start behaving funny at -17 to -20c
 
There is a definite correlation to the cold. The ambient temperature is less important than the actual battery pack temp which is affected by many variables such as how much driving vs sitting you have been doing, when or if the battery heater has engaged, your SOC or if your plugged into shore power(wall charger). I am going to speculate that if your car was sitting long enough at an ambient of -13C that the battery probably got close to that temperature but not cold enough to trigger the battery warmer which seems to be around -17C. This ultimately triggered the BMS to limit incoming regen charge to only a few kw/hr(regen can hit 50+ kw/h).

I typically charge to 80-90% and have yet to see that message despite being even in colder temperatures. Again I suspect this is because I stay on auto regen most of the time and that I have been hitting the pack temperature threshold for the battery warmer to turn on. The other day when it was -32C, my battery warmer came on during the night and my actual pack temperature was +10C when I departed on my morning commute. This morning ambient temp is -16C but actual battery temp is -11C and there is no evidence the battery warmer came on at all during the night.
 
Totally normal. It would have been nice to have prompts that were more specific. I.e. too full, too cold, some other reason.
 
So, I haven't seen this situation yet. I live in MA and the temps have been quite low recently (-18C or 0°F). When the regen shuts off do you lose all the regen braking effect too or does the car simulate that effect still? Seems like it would be a bit unsafe to be used to regen level 3 and then to suddenly lose it completely. I know every time I drive our ICE car it takes me a few miles before I acclimate to zero braking effect when I let off on the accelerator pedal. Kind of like "woah Nellie!"
 
Jgood said:
So, I haven't seen this situation yet. I live in MA and the temps have been quite low recently (-18C or 0°F). When the regen shuts off do you lose all the regen braking effect too or does the car simulate that effect still? Seems like it would be a bit unsafe to be used to regen level 3 and then to suddenly lose it completely. I know every time I drive our ICE car it takes me a few miles before I acclimate to zero braking effect when I let off on the accelerator pedal. Kind of like "woah Nellie!"
Click to expand...

It's not too bad once you get used to it. I turn off regen in snowy conditions to avoid under steer and I find the brakes seem to be less grabby and more like a normal ICE vehicle when regen is off. I does feel weird after one pedal driving for a while though. The car does not simulate regen when it cannot use regen, at least not as far as I know. Auto regen always seems to work for me regardless of full charge.
 
Kathryne said:
... The car does not simulate regen when it cannot use regen...
Click to expand...
It took me a moment to absorb that but I see what you mean. Yes, I would guess that the disk brakes don't apply themselves when you back off the accelerator with a regen level set, but 'unavailable'. Technically they could, but that feature must be outside the scope of design, unless that is what is happening as you describe when 'auto regen' is set?
 
My car reports Regen unavailable all the time. Sometimes the paddles literally do nothing in that situation and I need to jump on the brakes to stop. Sometimes it gives me the warning but paddles work fine and I can use them to come to a stop. Sometimes I get the message at the start of a trip and paddles don't slow the car but later on the same trip, the message still comes up, BUT the paddles now work fine. Oh, and when all this is happening, no matter what the paddle and brake function is like, the "Regen counter" on the dash keeps racking up the regen distance gained but I have ZERO idea as to whether the juice is actually going back into the battery. Good times.
 
I still can't comment on "playing in the snow", but I have been noting the charge
and discharge power limits reported via OBD2. A couple of days ago when
the pack was really cold, the charge limit said 77 kW or so. I didn't go anywhere,
I just looked when moving the car in the driveway. Today, after just sitting in
warmer temps, it reported the normal 157 kW figure I usually see. Discharge
limit was mostly unchanged in both cases. SOC was about 60%.

Those charge/discharge figures are a little bogus as they seem to reflect
more than the car is capable of, but there's definitely some temperature
dependence. Mostly for charging, which lithium chemistries are a little
more picky about.

_H*
 
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