Is my capacity really this low?

[Den]

I've been searching around, but I haven't yet found: Is there a chart or formula somewhere for estimating temporary capacity loss due to low ambient temperatures?

Thanks!

I have measured it with QC (it always shows REAL percentage!). At -10C (26F) it charges only till 87,5% (that means 3kWh less).

 

[TonyWilliams]

I've been searching around, but I haven't yet found: Is there a chart or formula somewhere for estimating temporary capacity loss due to low ambient temperatures?

Thanks!

I have measured it with QC (it always shows REAL percentage!). At -10C (26F) it charges only till 87,5% (that means 3kWh less).

I would not put a lot of faith in those quick charger displays. But, if the battery is cold, it certainly will significantly inhibit the speed and quantity of charging. That is a fact.

The good news is the quick charger will quickly warm the battery the closer it gets to 100%!!!

 

[Den]

I would not put a lot of faith in those quick charger displays. But, if the battery is cold, it certainly will significantly inhibit the speed and quantity of charging. That is a fact.

The good news is the quick charger will quickly warm the battery the closer it gets to 100%!!!

I have "measured" it twice in two different ways.

I have QC in about 2km from office where I charge from electricity socket. First day I have charged to "full" (100%) in office garage (cold) and after that drove to QC and just read its value. It was 86% (of 24kWh - QC shows full (not usable) capacity, e.g. if you'll drive to it "empty" it still shows 12% that is about 3kWh and we know it is reserved). I've calculated how much I have "burned" to get here (2,3km) and get final result: 87,5% when "full" at -10C.

Next day I charged a little less than to 100% in office, drove again to QC (now it showed 81%), started charging and went to near small shop. When I was back, QC stopped automatically at 87% - that means it wasn't able to charge more because of cold. I pushed "start" again, and very slowly (with current reading of 1A) it pushed a little beat more till 89% - maybe because of warming a little beat a battery. But it never will charge it till 100% I guess on such low temperatures.

And temperature reading in Leaf's display was 3 bars both days.

 

[Computerizer]

The last couple days I've been tracking some data carefully to try to see what my capacity might be. I've been tracking mi/kWh, distance, and the time-to-charge-to-80% from the dash and the beginning and end of each trip. I look up the time-to-charge in the spreadsheet that was pointed out here to find my % usable energy. I can then use these data to compute an estimate of the max capacity of my battery. So far it's come out, on average, to be about 22.1 kWh (4 trips).

HOWEVER, I've noticed something odd about the spreadsheet. Right now, for example, my car's dash says 14:00 to 80% on 120V. If I look at this on the spreadsheet, it says this is 3 bars, 29% capacity, etc. But mine only has one bar showing, not 3. What's up with that? My question is, if I've only got 1 bar showing, does that mean I only have between 13% and 17% of battery, or do I really have 29%? Which part of the spreadsheet is correct?

 

[mwalsh]

HOWEVER, I've noticed something odd about the spreadsheet. Right now, for example, my car's dash says 14:00 to 80% on 120V. If I look at this on the spreadsheet, it says this is 3 bars, 29% capacity, etc. But mine only has one bar showing, not 3. What's up with that? My question is, if I've only got 1 bar showing, does that mean I only have between 13% and 17% of battery, or do I really have 29%? Which part of the spreadsheet is correct?

Two bars (actually 1.5 in reality) hidden below the two red bars on the dash.

 

[planet4ever]

I look up the time-to-charge in the spreadsheet that was pointed out here to find my % usable energy. I can then use these data to compute an estimate of the max capacity of my battery. So far it's come out, on average, to be about 22.1 kWh (4 trips). HOWEVER, I've noticed something odd about the spreadsheet. Right now, for example, my car's dash says 14:00 to 80% on 120V. If I look at this on the spreadsheet, it says this is 3 bars, 29% capacity, etc. But mine only has one bar showing, not 3. What's up with that? My question is, if I've only got 1 bar showing, does that mean I only have between 13% and 17% of battery, or do I really have 29%? Which part of the spreadsheet is correct?

I should let surfingslovak respond, but my reaction is a) I doubt seriously that you have 22.1 kWh usable, and b) the mapping between hours and bars appears to be constant, not adjusting for battery capacity.

As the comments say, the chart assumes 21 kWh of usable battery capacity. To take an extreme example, if you only had 10 kWh usable capacity in the battery, it would probably take more like 10 hours to recharge fully from LBW, rather than the 21 or 22 that the chart shows.

Ray