[odbaranov]

Hi everyone!
I hope you’re all doing well! I just had a bit of a strange experience with my EV and wanted to share. I have an i5 edrive40 (550 km on dash), and when I parked it outside with 70% battery and went shopping, I noticed that it had dropped to 54% after just 20 minutes when I came back. I made sure the heating and everything else was turned off and that the car was locked. The temperature outside is around +3.5°C. Is this normal?

Thanks for any insights you might have, and wishing you all a Merry Christmas!

[RichardInCA]

Definitely not normal. Is there some reason that perhaps the app hadn’t updated with the most recent %SOC when you parked your car? (You can tell from the last trip in the app). Even with heat running there’s no way you’d use that much energy just in heating the car for 20mins.

[odbaranov]

Originally Posted by RichardInCA

Definitely not normal. Is there some reason that perhaps the app hadn’t updated with the most recent %SOC when you parked your car? (You can tell from the last trip in the app). Even with heat running there’s no way you’d use that much energy just in heating the car for 20mins.

It's kind of odd that this trip wasn't recorded at all, especially since it was over 1km! You'd think there would be some data for it.

[RichardInCA]

Perhaps your app just updated with the current SOC. I’d keep an eye on it and see what happens. I just can’t imagine anything that would cause your car to lose 16% SOC - that’s 0.16 * 81kwH =12.96 kWh! Seems much more likely to be an app/software glitch.

[odbaranov]

Originally Posted by RichardInCA

Perhaps your app just updated with the current SOC. I’d keep an eye on it and see what happens. I just can’t imagine anything that would cause your car to lose 16% SOC - that’s 0.16 * 81kwH =12.96 kWh! Seems much more likely to be an app/software glitch.

Thanks, but I charged the car yesterday from 24 to 80% and it was 45 kWh, and I drove only 35 km. So it is a terrible situation
I am planning to visit Service tomorrow.

[btlalum]

That does seem like an awfully fast loss. That said, the batteries in a BEV will lose SoC just sitting there as the temperature drops owing to increased internal resistance, general slow down of the chemical reactions and the like. In my five years of owning a Tesla S, driving in the northeastern United States in winter did require some getting used to those sorts of things. Tesla allows preheating of the battery prior to departure, so the situation upon setting out was pretty good, and the thermal management did a reasonable job of keeping the battery optimized. But the effects of low temperature just can't be gotten around completely owing to the physics.

I've not seen battery precondition available on my i5 except for Level 3 charging and/or the cockpit HVAC.

[RichardInCA]

Originally Posted by btlalum

That does seem like an awfully fast loss. That said, the batteries in a BEV will lose SoC just sitting there as the temperature drops owing to increased internal resistance, general slow down of the chemical reactions and the like. In my five years of owning a Tesla S, driving in the northeastern United States in winter did require some getting used to those sorts of things. Tesla allows preheating of the battery prior to departure, so the situation upon setting out was pretty good, and the thermal management did a reasonable job of keeping the battery optimized. But the effects of low temperature just can't be gotten around completely owing to the physics.

I've not seen battery precondition available on my i5 except for Level 3 charging and/or the cockpit HVAC.

While this is all true - I don’t think the OP’s situation is physics. They were away from their car for 20mins….that 12-13kWh loss would be on track for 3x that over an hour, so that would be 36+ kW rate of loss - that’s way over any kind of parasitic drain I can imagine, heck my L2 charger only puts back charge at 9kW.

[btlalum]

I agree, it does seem too much...but I wasn't talking about parasitic drain (electronics, pumps, heaters) but rather that a battery at a higher temperature will show a lower SoC if left out at a lower temperature even if it's not connected to anything else. It does seem high for that, but such does factor into EV use (though likely not so much for southern Californians and a lot of the Bay Area!). It will be interesting to hear what the service folks have to say about it either way.