[Q2RD2100]

Is there another known fix for the rapid percentage drops other than the 0-100% to deep 12 V cut-off recalibration?
It was driving me crazy two weeks ago when a cold front came through and there were a couple of times I didn't think I would make it home after the rapid drops of 10%.
If it is "just the gauge", I don't want to take my HV down to 0% because I think it will do more harm than good. Hopefully there is a soft reset that can be done? Anyone?

 

[Electric Tire Shredder]

No "soft" reset that I know of* BUT the % shown on OBD is reportedly what the motor goes by, stopping only when IT reads 0%**, regardless of what the car's display says. So when it gets low, you could just go by OBD instead of the car's gauge. Last time I checked when my uncalibrated gauge unexpectedly dropped to 11%, OBD showed 18%.

If you do try this, please let us know how it goes.


*OBD text pretty strongly implies its "goal" of 0.00% is required in order to recalibrate SOC.
**Someone (above?) doing a full-discharge recalibration reported that the motor kept running after the GAUGE hit 0%, & didn't stop until OBD hit 0%.

 

[twinturboz]

Im not finding any crazy drops in % since that one time it did it months ago but i am now noticing range loss, my mile per kw is down to 4.5miles/KW when it was warmer it was 5.1-5.2mi/kw. I get home with 64-65% remaining when its usually 69-70% im guessing its the air density when colder creates more aero drag plus the battery takes a hit when its cold also. Tire pressures have been adjusted already 2 weeks ago to account for the colder weather.

 

[Electric Tire Shredder]

That all makes sense. Also maybe tires being stiffer in cold. I assume you would have mentioned if you were using any heat (cabin or seat). Getting dark earlier can mean more headlight use though.

Less power available from the colder battery shouldn't affect miles/kWh, but would still leave you with less % at the end of the day, since it's effectively like the battery temporarily shrinking.

 

[twinturboz]

That all makes sense. Also maybe tires being stiffer in cold. I assume you would have mentioned if you were using any heat (cabin or seat). Getting dark earlier can mean more headlight use though.

Less power available from the colder battery shouldn't affect miles/kWh, but would still leave you with less % at the end of the day, since it's effectively like the battery temporarily shrinking.

More headlight use definitely both ways and especially fogs in the am as it gets very foggy in my neck of the woods, heat? None so far it’s been cold but I bundle up so I don’t have to use the heater, I have used the seat warmer a couple times but it gets so hot so dang fast I turn them off after 5mins and don’t turn em back on.

 

[Kiesling]

My guess is there is a lot of loss to battery conditioning in cold weather. One way to check would be to turn your car on for 15 minutes before you leave when it is still plugged in. That should help with letting the car get to it's desired temp without taking energy from the battery.

For the older 500e's with the TomTom unit, does it report where the energy is being used (drive motor, climate control, battery conditioning etc.)?

 

[Electric Tire Shredder]

Battery conditioning would likely be a big factor when it's below freezing, but not so much for twinturboz' recent observation near the Southern California coast. I'd also think it would activate itself if needed while charging, without even turning the car on, like it does for chilling via A/C when it's hot out. That may be one reason why zero-degree range is much better when timed to finish charging right before driving.

I'd bet twinturboz' 5% more drop than normal is from adding up the combination of colder battery temporary capacity reduction, cold air density, cold tires, headlights, foglights & a bit of seat heat, each of which add at least a bit of power use compared to his prior routine.

 

[Kiesling]

Capacity reduction due to cold has nothing to do with power used. But I'm not sure exactly how the mi/kWh is measured, but I don't see how a cold battery would influence the energy consumed by the car - unless the car is actively consuming power to condition the battery.

Even in 50 degree F weather I notice significantly lower efficiency in the first part of a drive vs. once the car warms up. I run my tires at 40 psi cold, so I don't think is the tires warming up. Mostly city driving speeds so I don't think air density plays a role. So my guess is battery conditioning is the most likely explanation.
Does the TomTom show energy use breakdown for those with pre 2016 cars?

 

[Electric Tire Shredder]

Right, I meant that temporary capacity reduction is part of what caused twinturboz' % drop, but not the mi/kWh efficiency drop. The latter would be at least partly due to all the other factors added up.

Going from 85F to 50F increases the air density by about 7%. We know that aerodynamic drag is a HUGE factor for efficiency, so that could explain at least part of the drop in mi/kWh, even at "city speeds" where even just 30mph gives about 30% less mi/kWh than 20mph.

It would NOT explain an increase in efficiency after driving a while, which makes me wonder how you're measuring that. Maybe by resetting the trip gauge after a few miles.

Sorry but my 2013 didn't come with a TomTom. I have AlfaOBD though, which might show power use breakdown somewhere.

 

[Kiesling]

It would NOT explain an increase in efficiency after driving a while, which makes me wonder how you're measuring that. Maybe by resetting the trip gauge after a few miles.

Correct. But without having a breakdown of where the energy is going, it is just my guess that it is going to battery conditioning. I believe cars like the Bolt provide this breakdown so you know what is consuming your energy. I really need to do a more controlled test to confirm this observation. Like drive the same exact stretch of road when the car is "cold" and go back and drive the same stretch of road at the same speed after it has "warmed up" and see what I get.