The 40KWH Battery Topic

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Had to drive in for my 6 month service and the battery plate recall. My dealer is 90 miles from my home.

Left at 100% and arrived at exactly 15%. So 85% to drive 90 highway miles at 70 mph with a bit of terrain. Not sure if this shows I have lost real range as I do not do the drive often. But I remember driving it home having a lot more left.

Fast charged back to 83% in about 28 minutes. That fast charge jumped my batt temps from about 70f to 116f for the highest sensor. After my service I'll need to charge a bit more. Of course the nissan dealer let their fast charger break and wont fix it so a Honda dealer near by is picking up the slack. Thank you Honda!

DC fast charging did not appear to change my HX or SOH. Will post full batt stats next week.
 
Added detail on the battery for the trip:
So in the car it said I went from 100% to 15% but my kWh used for the 90 miles was 26.54. That sure seems like they are holding more in reserve than I thought. I thought about 36 kWh was useable. But 26.54/36 would have been 74% used not 85% as I did.

As a side note I got 3.33 miles per kWh average for the 90 miles at 70mph
 
In my experience, Nissan seems to want you to think you have far less battery remaining than you actually do. I find it falls mostly linear until about 50% than far faster until about 10%. On several trips I've seen the GOM drop to 10%, rise back over 20% then very slowly drop back down all while driving at consistent highway speeds. Leafspy readings seem to be consistent throughout and at 2% on the GOM, Leafspy was still showing 6.4 kWh remaining. Here are some stats from that trip - my most inefficient one yet!

Conditions: -29C (-20F), dark, 15 kph (9 mph) crosswind, mostly flat terrain, 106km (66mi) round trip, average speed 75 kph (47 mph)

Start:
GOM: 100%, 174km (109mi)
Leafspy: 34.8 kWh available, battery temp 2.2C (36F)

Finish:
GOM: 2%, ---km, very low battery warning
Leafspy: 6.4 kWh available, 29.8 kWh used (I know, the math doesn't add up!), battery temp 16.3C (61F)

Efficiency: 3.56 km/kWh (2.22 mi/kWh) => calculated range of 124km (77mi) based on original 34.8 kWh indicated by Leafspy and assuming it would keep going to 0 kWh indicated.
 
Excellent info!

On my return trip I went from 100% to 24%.
Leafspy shows 34.1% remaining as opposed to the cars 24%.

My return efficiency was also a bit higher. I made some stops but the longest segment had the lowest average was 3.56 mi per kWh. Had to check out the status of a EA charger.

I also noticed 100% charge is 96.4% (401.5 v) in leafspy. Once before I charged to 100% and saw 98.7% in leafspy (403.49 v)
 
danrjones said:
Excellent info!

On my return trip I went from 100% to 24%.
Leafspy shows 34.1% remaining as opposed to the cars 24%.

My return efficiency was also a bit higher. I made some stops but the longest segment had the lowest average was 3.56 mi per kWh. Had to check out the status of a EA charger.

I also noticed 100% charge is 96.4% (401.5 v) in leafspy. Once before I charged to 100% and saw 98.7% in leafspy (403.49 v)

Notice your GOM is "bloated" at full charge, then seems to drift downwards rapidly. This is because its building its hidden reserve. I have found my GOM on full charge to be well within 5% of my actual range but still tells me I am at double _ _ _ (GOM and SOC) when LEAF Spy says I have 15 more miles of range. This is why LEAF Spy is so valuable. It adds 15 "stress free" miles to your usable range.
 
I have pretty well ignored the GOM. I pay more attention to %. Its obviously not perfect but I find it more useful.

I'm thinking the GoM uses your rescent efficiency in its calculation. So most of the time we are in town and getting 4 to 5 miles per kWh. Then today I get on the highway and suddenly I'm getting 3.3 over two nearly full charges. I do not think it adequately takes that into account. When I left this am it said something like 160 miles. Lol

Maybe at 45 mph.
 
danrjones said:
I have pretty well ignored the GOM. I pay more attention to %. Its obviously not perfect but I find it more useful.

I'm thinking the GoM uses your rescent efficiency in its calculation. So most of the time we are in town and getting 4 to 5 miles per kWh. Then today I get on the highway and suddenly I'm getting 3.3 over two nearly full charges. I do not think it adequately takes that into account. When I left this am it said something like 160 miles. Lol

Maybe at 45 mph.

I think you missed my point. The only time I look at it is on a full charge. Since I have LEAF Spy, I see no reason to look at it any other time. I also reset my trip computer daily so figuring out my range from a charge that might last 3 days is also not really possible either.

As far as how the GOM calculates range, you are correct and that has been true since day one but I do see the GOM becoming more accurate. Previously, it would be as much as 20% off at full charge. I mentioned it being being less than 5% off on my 40, but there were a few times it was nearly dead on so it is considering more driving history than earlier versions of the LEAF.

But range predictions shouldn't be considered more than simply one data point among several you need to consider. Its like Tesla's range predictions. They have the same issues and some people swear by it while others swear at it. In the end, the range is still on you.
 
My Fall stats - a bit late:

AH: 105.97

SOH: 91.80%

PACK VOLTAGE: 379.51

Hx: 105.75

ODOMETER: 2843 MILES

SOC: 77.8%

18 QCs & 97 L-1/L-2S

24 MV Differential


NOTES:

* My efforts to preserve capacity by cooling the garage in hot weather don't seem to have done much - unless the SOH would be worse without them, in which case this is NOT a very heat-resistant pack. Degradation seems to be averaging a little over 5.3% a year with garage cooling.

* I almost never charge to 100% anymore, but the pack is still fairly well balanced. One EQ charge every 6 months is probably all I need.

* Yes, the odometer reading is correct.
 
LeftieBiker said:
My Fall stats - a bit late:

AH: 105.97

SOH: 91.80%

PACK VOLTAGE: 379.51

Is the pack voltage something to watch? I assumed everyone would have close to the same voltage at full and empty, but their AmpHrs would vary based on degradation.

I live in a much hotter area than you and here are my specs as of yesterday after a long trip for service, all from leaf spy. I parked outside day and night.

AH: 107.52

SOH: 93.14%%

PACK VOLTAGE: 345.54V

Hx: 105.32

ODOMETER: 3040 MILES

SOC: 34.2%

4 QCs & 166 L-1/L-2S

18 MV Differential


One interesting thing to note is that yesterday's trip with a fast charge in the middile jumped my HX from 104.83 to 105.32 in one day. It has been going down until then from our cooler weather (I presume).

Also note my 3 month adjustment is coming in about 2-3 weeks. If there is one.
 
Yeah, wondering if more exercise would help pack numbers. I know someone who recently went to a Plus (a common thing it seems ;) ) but had 50,000 miles on his 40 kwh and just under 91% SOH.

My stats 25,185 miles, ahr 106.47, SOH 92.23%, HX 117.23% 261 QCs, 200 L2's.

And.... well, some people never learn and I guess I am one of them :)
 
Saw about a 0.5% drop this past month. Batter SOH at 93.71% with a build date of February 2018.

Date SOH% SOH %Chg Ahr Ahr %Chg TempF

3/15/19 97.47 -2.53% 112.52 -2.53% 69.1
4/15/19 97.41 -2.59% 112.45 -2.59% 75.2
5/15/19 97.34 -2.66% 112.37 -2.66% 82.2
6/15/19 95.38 -4.62% 110.11 -4.62% 90.8
7/15/19 94.98 -5.02% 109.64 -5.02% 97
8/15/19 94.63 -5.37% 109.24 -5.37% 101.8
9/15/19 94.41 -5.59% 108.99 -5.59% 92.2
10/15/19 94.26 -5.74% 108.81 -5.74% 81
11/15/19 93.71 -6.29% 108.18 -6.29% 52.5
 
golfcart said:
Saw about a 0.5% drop this past month. Batter SOH at 93.71% with a build date of February 2018.

Date SOH% SOH %Chg Ahr Ahr %Chg TempF

3/15/19 97.47 -2.53% 112.52 -2.53% 69.1
4/15/19 97.41 -2.59% 112.45 -2.59% 75.2
5/15/19 97.34 -2.66% 112.37 -2.66% 82.2
6/15/19 95.38 -4.62% 110.11 -4.62% 90.8
7/15/19 94.98 -5.02% 109.64 -5.02% 97
8/15/19 94.63 -5.37% 109.24 -5.37% 101.8
9/15/19 94.41 -5.59% 108.99 -5.59% 92.2
10/15/19 94.26 -5.74% 108.81 -5.74% 81
11/15/19 93.71 -6.29% 108.18 -6.29% 52.5

So we have three 2018's with various mileage (you didn't say yours but I'll guess its not the same) and all three are showing similar SOH.
91.8%, 93.14% and 93.71%
 
Looking at all this data, the capacity in A-hrs seems to decay at a rate of about 0.5 A-hr per month, regardless of whether it is driven a lot or a little, or when or how it's charged.

Maybe there is a programmed decay rate in the VCM? There is a CAN buss data monitor item called "gradual capacity loss" which is used along with pack temperature to set the capacity bars on the dash.

Or maybe it's just a natural rate of the irreversible chemical reaction within cells. Once electrolyte gets added to a cell, then the life-clock starts ticking down.
 
danrjones said:
golfcart said:
Saw about a 0.5% drop this past month. Batter SOH at 93.71% with a build date of February 2018.

Date SOH% SOH %Chg Ahr Ahr %Chg TempF

3/15/19 97.47 -2.53% 112.52 -2.53% 69.1
4/15/19 97.41 -2.59% 112.45 -2.59% 75.2
5/15/19 97.34 -2.66% 112.37 -2.66% 82.2
6/15/19 95.38 -4.62% 110.11 -4.62% 90.8
7/15/19 94.98 -5.02% 109.64 -5.02% 97
8/15/19 94.63 -5.37% 109.24 -5.37% 101.8
9/15/19 94.41 -5.59% 108.99 -5.59% 92.2
10/15/19 94.26 -5.74% 108.81 -5.74% 81
11/15/19 93.71 -6.29% 108.18 -6.29% 52.5

So we have three 2018's with various mileage (you didn't say yours but I'll guess its not the same) and all three are showing similar SOH.
91.8%, 93.14% and 93.71%

Mine was 92.23% SOH @ 25185 miles
 
My wager is the BMS is managing down the pack to give it the best chance to stay at or above 70% at the 8 year mark (or 100K miles). I wonder if pulling it down a bit quicker than natural decay helps preserve the battery a bit better.
 
danrjones said:
So we have three 2018's with various mileage (you didn't say yours but I'll guess its not the same) and all three are showing similar SOH.
91.8%, 93.14% and 93.71%

I'm currently at only 11000 miles. The car sat on the lot for over a year (presumably at a high SOC) before I leased it.
 
Back
Top