2013 Car to car battery variability

My wife and I each have a 2013 Leaf. Both built May 2013, both purchased in the summer of 2013, approximately 2 weeks apart. Both are parked outside, under trees, about 10 feet apart. We both get 4.0-4.2 mi/kwh so we probably have similar, moderately conservative driving habits. She now has 51k miles and I have 37k miles, so she drives somewhat more than I do. Charging has always been to 100%, almost all L2 at home. She has had about 10 L3 charges, total, I have had none. She has never driven to turtle, I have 5 times (once unintended, the others for testing).

I figure these are about as close to comparable as anyone can get, other than perhaps fleet purchases. What I find most interesting is the graph below. She still has 12 bars, I lost my first bar at about 36K miles. Looks like her battery is deteriorating significantly less quickly than mine. I wonder if this is mostly due to the turtles I've had? Maybe just bad luck for me? (or good luck for her). Each time I have turtled the car, it has been hooked up to an L2 charger within 15min of turtle. Her car has had a max temp of 7 bars once for about 12 hours. Occasional 6 bar temps. But both cars are almost always at 5 bars, rarely 4 bars in winter.

Graph shows SOH vs Date. You will have to click on the rotate icon to view properly, then the zoom icon.


https://app.box.com/s/bbymzwhtn24b114clh093z954deizlw0



Sorry, I couldn't figure out how to post the image, click on the link and you should see it. (Yes, I read the FAQ).

I think it's the 'turtling'. The pack doesn't seem to be harmed by being run to 10% or so if recharged immediately, but run it that low and damage is being done, even if minor.

I suspect the DCQCs have helped her car. I see increase in AHr, SOH, and Hx after DCQC and drop after gentle driving. Turtle is probably not too detrimental as long as it does not sit deeply discharged for more than an hour or so.

Turtle is probably not too detrimental as long as it does not sit deeply discharged for more than an hour or so.

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I think that the key word is "too." Multiple very deep discharges would likely produce a noticeable drop in capacity that wouldn't show with one or two.

Very interesting !
Does Ahr map out the same ?

I have suspected battery quality variation for a long time, but a lot more data is required to firm up my suspicion. This is one more reason to prefer purchase of a used LEAF over a new one.

Do both vehicles spend most of their time parked outside at home? Or do one or both of you take them to work (different places?) or some other place where they sit for many hours at a time?

That is interesting that you say "rarely 4 bars in winter". I've been sometimes seeing 4 temp bars in winter now and I live and work south of you... But honestly, the temp bars are crap. I go by the sensor readings in Leaf Spy.

For example, I've seen 4 temp bars when my sensor readings were high 57.4 F, average 57.1 F and lowest 57.0 F with 61% SoC showing on the dash display and 146 gids. Yet the day before, I'd see 5 temp bars with these temp sensor values: H 58.5 F, A 58.0 F, L 57.4 F, 39% dash SoC and 94 gids. (I take pics of my dash along with a Leaf Spy screenshot within a minute of each other. I can go back and compare their date and time stamps.)

You don't hit and stay at 6+ temp bars in summer?

Your build month is the same as mine. Carfax and Autocheck both say my car was manufactured 5/23/13. Carfax reports it was sold (rather leased) 6/22/13. Autocheck has ODOMETER READING FROM DMV on 6/22/13 of 16 miles and Carfax has something equivalent.

http://www.mynissanleaf.com/viewtopic.php?p=511915#p511915 was my 1st bar loss in Nov 2017 at almost 50K miles. I'm still at 11 bars with SOH 82.xx to 83.xx% or so past 62K miles. I've never turtled my car but can't speak to the previous driver. I have no CHAdeMO inlet so the QC count is 0. I bought it used in July 2015 so I have no idea of the habits of the previous driver. The previous driver had it serviced at Premier Nissan of Stevens Creek in Santa Clara.

So is the lesson... don't let the battery get to turtle mode???

SageBrush said:

Very interesting !
Does Ahr map out the same ?
.

Click to expand...

AHr for her car have gone from 60.9 new to 57.8 now, a drop of 5% from new. My car has gone from 60.5 to 54.9, a 10% drop. Similar looking graph.

cwerdna said:

Do both vehicles spend most of their time parked outside at home? Or do one or both of you take them to work (different places?) or some other place where they sit for many hours at a time?

That is interesting that you say "rarely 4 bars in winter". I've been sometimes seeing 4 temp bars in winter now and I live and work south of you... But honestly, the temp bars are crap. I go by the sensor readings in Leaf Spy.

For example, I've seen 4 temp bars when my sensor readings were high 57.4 F, average 57.1 F and lowest 57.0 F with 61% SoC showing on the dash display and 146 gids. Yet the day before, I'd see 5 temp bars with these temp sensor values: H 58.5 F, A 58.0 F, L 57.4 F, 39% dash SoC and 94 gids. (I take pics of my dash along with a Leaf Spy screenshot within a minute of each other. I can go back and compare their date and time stamps.)

You don't hit and stay at 6+ temp bars in summer?
...

Click to expand...

Both cars spend most of time at home. We are both retired. She drives more in south bay area than I do, obviously she is on the road more hours than me. She occasionally (twice a month maybe) spends a few hours parked in one of the south bay shopping mall parking lots, so I guess her car has a bit more exposure to hot asphalt than I do (besides being on the road more hours than me).

Max temp ever for my battery is 76.8 F with 5 bars on temp display.
Min temp ever is 38.2 F with 4 bars.

Max temp for wife's car is 81.0 F, 6 bars (probably after a L3 charge)
Min temp for her is 49.2 F, 4 bars. (I had 53 F, 4 bars on same date)
I have less data on my wife's car. I do not have data for her car on the date of my minimum temp ever.

I have NEVER hit 6 bars in my car.
My wife's car has only hit 6 bars once. All other summer data is 5 bars.

^^^
That's a bit surprising re: your max temps.

FWIW, I was at 4 bars this afternoon with temp sensors reading H 55.9 F, A 55.6 F and L 55.4 F.

On hot summers, ambient temps can reach 90s to even over 100 F sometimes where I live and work.. On those hot days, If I'm not at work (e.g. weekends/days off), I sometimes can't avoid my battery getting past 90 F due to ambient temps even w/0 charging at all (none in the morning, none in the afternoon). I'm in a hotter part of the South Bay.

If I L2 charge to full or nearly full (finishing by say 7:30 pm), drive on the highway somewhere then return to my work to L2 charge more, even after dark, my battery temps can get pushed into the mid 70s F, which is well above ambient temp.

I've talked about it getting past 90 F outside air temp at my work during summer (my home would be no different) at http://www.mynissanleaf.com/viewtopic.php?p=509210#p509210 and luckily, at work, I can park in a slightly underground area that stays cooler. I really try to park down there or the underground parking of a building that's far away when OATs are warm (say 85+ F).

Right now, 5:20 PM, ambient is 55 F. My car shows 4 bars, LeafSpy temps 56.5/57.0/56.8. I did not drive the car at all today.

Palo Alto is cooler than areas south. Max summer temps usually in the 80s, quite rarely in the 90s. Night time cools to low-mid 60s in the summer.

Also, possibly significant, is our driveway is completely undeveloped. We park on a 2" thick mat of decaying leaves from the trees overhead. That is where the cars spend most of their time.

cwerdna said:

I really try to park down there or the underground parking of a building that's far away when OATs are warm (say 85+ F).

Click to expand...

I don't pay much attention to ambient unless I am charging but I DO avoid parking on asphalt that has been cooking in direct sunlight.

OP: Our cars have a very similar story so far as care and climate, and our use is closer to yours rather your wife's. Current SOH is 81% and Ahr is ~ 56. Manufactured 10/2013 and put into service 04/2014.