Erroneous message that battery is fully charged in cold weather?

Slamming a lot of current into a cold battery isn't a particularly
good idea in general, especially when it risks pushing cell voltage
above 4.2, so the car is trying to help both you and itself.

_H*

 

I do notice that charging jumps from 98% to 100% after only 5 addition minutes charging at 1.6kW. The normal increase at that rate is 2% SoC per hour.

 

Yup, all the time for the past couple of (cold) weeks. Sometimes the warning comes up after I have been driving for quite a while and there's clearly lots of headspace available in the battery. Also, the message will come up even while the Regen "counter" on the speedometer is counting up the regen distances being generated. Sometimes when the message comes up I cannot use the paddle to slow or stop but other times the paddle works fine even as the message is being displayed.

 

I've noticed a couple of different situations: when I am fully charged and try to use the Regen paddle, shortly after starting out, the "can't Regen, battery is fully charged" message will come up (along with a chime) and the paddle will have ZERO effect. I need to use the brakes to stop.

Next day, same situation, I pull the paddle, chime and message appears, but the paddle WORKS, Regen metre shows it's making power and the car slows and stops using only the paddle.

Also, I will get this same behaviour after driving for 15 minutes (battery clearly can't be full anymore)

Sometimes I wonder if the car actually means "battery is too cold" but they just didn't create a proper message for the display.

 

I think what hobbit mentioned is the culprit. When you regen it can be as much as a 150+ Kw/h hit . Depending on the temperature the BMS is making the executive decision to decline the fairly large incoming charge even if there is small battery headroom available.

 

I know this at an intuitive level from watching the Prius, where slowing on a
cold day only regens at like 30 - 40 amps on a pack that can take up to
100, and the hydraulics come in to help. As I drive more and the pack
warms up, the limit gradually increases. Most Prius drivers can't tell the
difference since there's no instrumentation to show this. But it's pretty
standard [and important] BMS behavior at this point.

_H*

 

Are you guys using winter mode when this happens?I haven't seen the regen.unavailable/fully charged alert.Just that snow flake to warn of potential ice. I don't charge to 100% unless it's for a road trip,or I have a lack of charging once on the road. 90% at most.

 

I always start off at 100%. And it's cold in Ontario. Winter Mode is on.