GID/capacity increases as cooler weather returns

[mwalsh]

I was up to 89.6% / 252 Gids this morning. As far as I can tell with a quick look at my spreadsheet, that's the best I've had since July. Unfortunately, it's just in time for another warm spell of weather. But winter was rather nice, at least for the three days it lasted. :? I also saw 100 miles on the GOM for the first time in I don't know how long (109 miles ECO).

 

[DaveinOlyWA]

I am back to 281!! never thought i would say that but the difference? garage temp almost 10º cooler at 51.8º F OAT is 37F.

but i recharged from 27 GID to 281 and used slightly less than 20 Kwh to recharge (my meter is analog with 1 Kwh resolution) which means i regained 254 GIDs and it took only 78.7 watts/GID to recharge?

so tell me, how does THAT work?

so, basically what it boils down to is that the LEAF's BMS is manipulating this value to control some other parameter for some sort of battery protection scheme.

so, is my "current" reading artificially high or was my Summer reading artificially low? i am guessing the latter to prevent overcharging as the temperature goes up...

 

[surfingslovak]

so, is my "current" reading artificially high or was my Summer reading artificially low? i am guessing the latter to prevent overcharging as the temperature goes up...

Yes, very likely. The sensors used for determining Gids could be temperature sensitive as well. For what it's worth, I measured 281 Gid last April with 5% range loss, which I confirmed through a series of range tests and by monitoring energy draw from the wall.

 

[mdh]

I am back to 281!! never thought i would say that but the difference? garage temp almost 10º cooler at 51.8º F OAT is 37F.

but i recharged from 27 GID to 281 and used slightly less than 20 Kwh to recharge (my meter is analog with 1 Kwh resolution) which means i regained 254 GIDs and it took only 78.7 watts/GID to recharge?

so tell me, how does THAT work?

so, basically what it boils down to is that the LEAF's BMS is manipulating this value to control some other parameter for some sort of battery protection scheme.

so, is my "current" reading artificially high or was my Summer reading artificially low? i am guessing the latter to prevent overcharging as the temperature goes up...

I believe the car uses machine learning algorithms and pulls in many factors including temperature (battery/ambient), charging frequency, driving style and and many other factors. I will bet that during a very hot day, the battery might even slightly discharge. During very cold days, the battery might even accept additional charging to minimize range impact. The problem with machine learning is that rapid changes can cause the model to be impacted or overshoot target bands. Flapping can also occur, requiring a certain amount of time for the model to settle down. This is where, I believe, battery damage can occur.

Who knows...I wish Nissan would talk more about their technology.

 

[DaveinOlyWA]

so, is my "current" reading artificially high or was my Summer reading artificially low? i am guessing the latter to prevent overcharging as the temperature goes up...

Yes, very likely. The sensors used for determining Gids could be temperature sensitive as well. For what it's worth, I measured 281 Gid last April with 5% range loss, which I confirmed through a series of range tests and by monitoring energy draw from the wall.

with 27 GID left (4.0 miles/Kwh) i probably could do another 6 miles before Turtle which makes the range right at 70-71 miles which is not a whole lot different than last year.

there were days when the range would have been in that neighborhood although most days the range appears to be in the 73-75 mile area but guessing the shorter range days were the colder days (did not record temps...bummer) it seems that when temps get below about 50º is when the range really starts to drop off

 

[LEAFer]

I believe the car uses machine learning algorithms and pulls in many factors ...

And ... is it possible that disconnecting the 12V battery (performed for whatever unrelated reasons) resets the parameters to factory default, requiring a (possibly lengthy) re-learning process to recent levels ? Just saying ... which might explain some odd behaviours some owners have experienced in regards to "range loss" and/or gid count.

 

[DaveinOlyWA]

I believe the car uses machine learning algorithms and pulls in many factors ...

And ... is it possible that disconnecting the 12V battery (performed for whatever unrelated reasons) resets the parameters to factory default, requiring a (possibly lengthy) re-learning process to recent levels ? Just saying ... which might explain some odd behaviours some owners have experienced in regards to "range loss" and/or gid count.

could it be that easy for Nissan techs to restore lost capacity bars?

 

[TonyWilliams]

with 27 GID left (4.0 miles/Kwh) i probably could do another 6 miles before Turtle which makes the range right at 70-71 miles which is not a whole lot different than last year.

there were days when the range would have been in that neighborhood although most days the range appears to be in the 73-75 mile area

So, your car can hit 275-281 Gid, but only go 70-75 miles at 4 miles/kWh ?

What is the battery temperature?

 

[DaveinOlyWA]

with 27 GID left (4.0 miles/Kwh) i probably could do another 6 miles before Turtle which makes the range right at 70-71 miles which is not a whole lot different than last year.

there were days when the range would have been in that neighborhood although most days the range appears to be in the 73-75 mile area

So, your car can hit 275-281 Gid, but only go 70-75 miles at 4 miles/kWh ?

What is the battery temperature?

5 TBs. garage temp 11 C, OAT 3C...not sure what you are asking here

but one thing that is clear; charging from VLB to full with 20 Kwh at 85% means I have 17 kwh of power to use

 

[TonyWilliams]

with 27 GID left (4.0 miles/Kwh) i probably could do another 6 miles before Turtle which makes the range right at 70-71 miles which is not a whole lot different than last year.

there were days when the range would have been in that neighborhood although most days the range appears to be in the 73-75 mile area

So, your car can hit 275-281 Gid, but only go 70-75 miles at 4 miles/kWh ?

What is the battery temperature?

5 TBs. garage temp 11 C, OAT 3C...not sure what you are asking here

Just asking what the battery temp is. It sounds like it's between 3C and 11C, which is likely the source of the diminished range. Does the car currently drive 84 miles range when it's warm?

 

[DaveinOlyWA]

Just asking what the battery temp is. It sounds like it's between 3C and 11C, which is likely the source of the diminished range. Does the car currently drive 84 miles range when it's warm?

yes or there abouts. Unless i actually drive that far, i am unwilling to say with any confidence but its pretty close to that. i edited the above post. what it boils down to is yesterday I had 17 Kwh of power (assuming 85% charging efficiency) added to battery plus 27 GID already in battery of which 2% (480 watts) is not usable makes about 18.68 Kwh

**edit** amended above to include the 27 GID already in pack

 

[TonyWilliams]

yesterday I had 17 Kwh of power (assuming 85% charging efficiency) to use

17kWh of 21 (81%) with 281 Gid, correct?

Just the low temps?

 

[DaveinOlyWA]

yesterday I had 17 Kwh of power (assuming 85% charging efficiency) to use

17kWh of 21 (81%) with 281 Gid, correct?

Just the low temps?

oh wait...bad math. still had the 27 GID so can use all but 2% (480 GID...thanks SS for pointing that out!) so have another 1.68 Kwh to use.

will edit above

 

[TonyWilliams]

Ok, so 89% (18.68 Kwh / 21kWh)

So, it was chilly. Sounds normal, and why we correct for temperature of the battery separately from Gid count.

 

[DaveinOlyWA]

Ok, so 89% (18.68 Kwh / 21kWh)

So, it was chilly. Sounds normal, and why we correct for temperature of the battery separately from Gid count.

prime example of why we struggle to understand and why Nissan is failing to provide more information.

last night drove 63.9 miles and temps slightly warmer by about 3º. home at 68 GID this time (back to normal??) recharged 17 Kwh to 274 GID. garage temp 11.4 C (.4 higher than yesterday) and OAT morning temp still same at 3C

so that extra mile cost us 40 GID? weird. now part of the explanation is that much lower humidity means less defrost to clear the windows but SO was driving so any kind of quantitative analysis on that aspect would be useless. (for one who is chronically late, asking her to judge time is a mistake...)

 

[kolmstead]

I didn't get my SOCmeter until after the worst of summer heat had passed, but it was still hitting 100 degrees. Six temp bars on battery. 80% charge averaged 188 GIDs. Last month, with five temp bars, I got 200-202 GIDs at 80%. But apparently the gains are over. This morning, I got 195 GIDs at 80%, with four temp bars.

I did two 100% charges last week, at five temp bars. 225 GIDs, 80%. No signs that equalization helped me, despite 10 months of strictly 80% charges.

Got about 62 miles before LBW last week with 100% charge; 47 miles today with 80% charge. To be fair, I did use heater today.

My LEAF, #257, has original firmware. 11 capacity bars, but I'm not far from losing another. 16,800 miles.

-Karl

 

[smkettner]

Today my initial range for the first bar has returned to when the car was new. About 8.5 miles.
With cooler weather I have been charging to 100% more often and today's morning commute seemed back to when it was new.
Sorry no GID meter.

 

[DaveinOlyWA]

i actually lost about 8-10 GID right after the weather turned colder. I have been parking outside for past 2 weeks and that will continue thru the holidays so wondering if the much colder ambient temps have caused permanent loss as pointed out in http://www.mynissanleaf.com/viewtopic.php?f=9&t=10728" onclick="window.open(this.href);return false;

now, another thought i had is my very unofficial range tests (not taken to turtle) along with my gut feeling says I have lost about 5% of my range and that slowly manifested itself over the Summer but the GID count stayed at 100% until just the last 2 weeks so...

 

[LEAFfan]

Today my initial range for the first bar has returned to when the car was new. About 8.5 miles.
With cooler weather I have been charging to 100% more often and today's morning commute seemed back to when it was new.
Sorry no GID meter.

I once got 14 miles (a record for me) on the top bar (12th) and another 12 miles (my record) from the second after a QC to 100% but was only 89% actual. On the freeway at 65mph actual (66-67mph), I'm getting 6 on the top bar now all the time. The top and bottom bars definitely hold more capacity than the rest. Since the cooler weather, charging to 100%, I've only seen a 3% increase on the gauge using L2.
A friend of mine went from 81% in the summer to 87% now, but no bar returned. I told him he may want to take it in and have Nissan reset his bars.

 

[DaveEV]

i actually lost about 8-10 GID right after the weather turned colder. I have been parking outside for past 2 weeks and that will continue thru the holidays so wondering if the much colder ambient temps have caused permanent loss as pointed out in http://www.mynissanleaf.com/viewtopic.php?f=9&t=10728" onclick="window.open(this.href);return false;

There is no reason to believe that the BMS does not protect the battery sufficiently in cold weather. Certainly not in the "cold" that you experience there in Olympia. Perhaps if you saw real cold there you might worry if you don't have the cold-weather package on your car.