Cold weather seems to limit power although the battery is warm - I`m at a loss...

[Holger]

hi folks,
i have to report strange behavior of my 2.0 signature (185 kW version). cold weather seems to limit power although the battery is warm.
yesterday it was 8 °C/47 F outside and i started with a rather cold battery also around this temperature. of course the car delivers only limited power - 100 kW - then as expected. after an hour the battery was cosy warm at 20 °C/70 F and even warmer later (75 F) but i could not suck more than ~ 120 kW. what might be the reason?
after this trip i immediately recharged the battery with about 40 miles (16 Amps current) and then set off again straight away. now that charging was stopped full power was available with the usual acceleration.

i have observed this behavior several times. the car doesn't behave this way when it's warm outside or - as i remember and mentioned above - immediately after charging.
but limiting power makes no sense when the battery is warm, even at freezing outside temperatures! this is weird, man...
any idea?

thanks!

Holger

 

[gregd]

Presume you've pulled the logs. Anything interesting in there?

I have a sort-of similar situation, though mostly in hot weather, where the car intermittently goes into Power Limited mode because it thinks the motor is overheating. The cause is that Sensor #2 is sending bogus (impossibly high) readings. It's either a loose or shorted connection somewhere, but I haven't been able to track it down. I wonder if you have a similarly intermittent sensor somewhere in the power train? There should be a log entry to that effect, even if it doesn't show up on the VDS.

 

[Holger]

thank you greg!

your fault seems to appear just the other way round - in warm environment as i understand.

i will discuss your useful hint with the experts at "mars orbiter" (conrad & his fellows) here in germany.
and no, i have not pulled a log but only checked the last alerts. nothing interesting among them.

 

[gregd]

Mostly in the hotter time of the year, but any time really. It seems to be triggered by a temperature change more than the absolute ambient temp. As things get hot the sensor contact seems to kind of "scrape", causing the intermittent (and by the laws-of-thermodynamics impossible) temperature jumps. Then it seems to settle down. I can drive somewhere and have several events along the way, then nothing on the way back after everything has had some time to soak in.

Definitely grab the logs. In my case, the errors are #1115 and #1116 (temp mismatch and overtemp for sensor #2), and they don't show anywhere in the cabin. Only when the combined temp hits some threshold is the "Power Limited" warning posted (flashed, usually - easy to miss) to the speedometer display. Still nothing on the VDS, but you definitely feel it in the pedal, and all is on display in the logs (often dozens of them!). Good luck!