Question on LeafSpy SOH results for 2018 Leaf with 5200 miles

Purchased June, 2018.
Current SoH: 96.90%
Odometer: ~ 5200 miles

Here's what's odd: I acquired an ODB-II connector approximately 5 weeks ago. At the time, Odometer was around 4200 miles with 96.96% SOH. So that indicates only a 0.06% degradation in 1000 miles of recent driving, which included a few QCs on par with previous charging patterns. Would be great if that holds up, only 6% loss in 100,000 miles.

Question is, what does this all imply? Does it mean the battery really lost 3% in 4200 miles / 6 months? Or could it mean it was well under 100% , 97-98% range when I purchased it? Is that expected? Maybe I should have gotten an ODB-II in advance to verify it was near 100% at purchase. Maybe dealer sold me a new car with a weaker battery. Thoughts? In the long run, if degradation is as it's been the last 1000 miles, I'm not too worried about it.

Other notes/questions: 100% charge indicated on the car consistently translates into 97.5% on LeafSpy, so just 2.5% reserved on the high end. Is it still a good idea to charge only to around 80% for new Leafs? On the low end, it's closer to 10% reserved, although I haven't gotten it low enough to measure that precisely. Does this mean when the car indicates 0% it will continue to operate for a while or will it shut off at 0% to protect the battery?

That's a lot of questions. I'll try to answer them. Keep in mind that the SOH answers are essentially educated guesses.

The SOH was likely between 99% and 100% when you bought the car. It likely did drop that much in the first few thousand miles, and likely would have dropped as much regardless of the mileage (within reason). My 2018 lost about 5% SOH in just 1200 miles, albeit over six months. The QCs you have done lately may have slowed the drop in SOH, but there is no evidence that this is actual slowing of capacity loss vs temporary inflation of the reading.

It is still a good idea to charge to roughly 80% when 100% charge isn't needed, and to try to charge to 100% right before using it when a full charge is needed. Using past Leafs as an indication, you will lose the SOC display before the car stops, at roughly 6% SOC. You don't want to get the car so low on charge that it begins to slow down a lot (Turtle Mode), much less run it until it stops. In fact, when you run it below 20% SOC you should recharge at least above 25% ASAP, unless the pack is also hot.

How was that?

LeftieBiker said:

That's a lot of questions. I'll try to answer them. Keep in mind that the SOH answers are essentially educated guesses.

The SOH was likely between 99% and 100% when you bought the car. It likely did drop that much in the first few thousand miles, and likely would have dropped as much regardless of the mileage (within reason). My 2018 lost about 5% SOH in just 1200 miles, albeit over six months. The QCs you have done lately may have slowed the drop in SOH, but there is no evidence that this is actual slowing of capacity loss vs temporary inflation of the reading.

It is still a good idea to charge to roughly 80% when 100% charge isn't needed, and to try to charge to 100% right before using it when a full charge is needed. Using past Leafs as an indication, you will lose the SOC display before the car stops, at roughly 6% SOC. You don't want to get the car so low on charge that it begins to slow down a lot (Turtle Mode), much less run it until it stops. In fact, when you run it below 20% SOC you should recharge at least above 25% ASAP, unless the pack is also hot.

How was that?

Click to expand...

Thanks. That's helpful.

markb1 said:

Question is, what does this all imply? Does it mean the battery really lost 3% in 4200 miles / 6 months? Or could it mean it was well under 100% , 97-98% range when I purchased it? Is that expected? Maybe I should have gotten an ODB-II in advance to verify it was near 100% at purchase. Maybe dealer sold me a new car with a weaker battery. Thoughts? In the long run, if degradation is as it's been the last 1000 miles, I'm not too worried about it.

Click to expand...

Also consider the date the vehicle was made not just the current mileage and when you bought it. Did it sit on the lot for 6 months, 9 months, or even a year before you bought it? I got a 2015 leaf brand new in November 2015 that was manufactured in December of 2014 and had been on the lot since January 2015. It was 97% when I took it home presumably because it had been on the lot for 10+ months sitting in the sun day after day at a high state of charge. I don't think anyone knows the exact formula for degradation yet but ambient temperature, total cycles, and calendar age appear to all be factors.

golfcart said:

markb1 said:

Question is, what does this all imply? Does it mean the battery really lost 3% in 4200 miles / 6 months? Or could it mean it was well under 100% , 97-98% range when I purchased it? Is that expected? Maybe I should have gotten an ODB-II in advance to verify it was near 100% at purchase. Maybe dealer sold me a new car with a weaker battery. Thoughts? In the long run, if degradation is as it's been the last 1000 miles, I'm not too worried about it.

Click to expand...

Also consider the date the vehicle was made not just the current mileage and when you bought it. Did it sit on the lot for 6 months, 9 months, or even a year before you bought it? I got a 2015 leaf brand new in November 2015 that was manufactured in December of 2014 and had been on the lot since January 2015. It was 97% when I took it home presumably because it had been on the lot for 10+ months sitting in the sun day after day at a high state of charge. I don't think anyone knows the exact formula for degradation yet but ambient temperature, total cycles, and calendar age appear to all be factors.

Click to expand...

Good points. June purchase in mild climate so outdoor heat probably not a big issue. Not sure of mfr date (odometer like 10 miles so few test drives) but the dealer seemed to always have the Leafs near 100% charge, presumably to hand them off to customer at 100%. Violates tip of not charging near 100% unless it's going to be used right away.

markb1 said:

Good points. June purchase in mild climate so outdoor heat probably not a big issue. Not sure of mfr date (odometer like 10 miles so few test drives) but the dealer seemed to always have the Leafs near 100% charge, presumably to hand them off to customer at 100%. Violates tip of not charging near 100% unless it's going to be used right away.

Click to expand...

You can find the manufacture date by opening up the drivers door and looking at the tag near the bottom right of the opening on my 2015. I'd imagine the 2018 is similar.

Please continue to keep track and give periodic updates, we don't have a lot of data on 2018s yet so every piece helps. My hope is that the larger packs are cycled less and do better in the long run but only time will tell.

Based on SOH I am tracking at just over 4% loss per year on my 2015 though my "real world" loss of range seems less than 15% compared to when it was new. I charge to 100% daily during the work week, because I have to for my commute, and we spend most of June - August near 90 degrees down in coastal Virginia. My first bar went at just under 45k miles so I can't complain, even with my car already being at 97% when I bought it I will be nowhere near a warranty replacement level at the current rate.

Your lower than expected loss of range is likely due to a common phenomenon: you learn to drive more efficiently in the first year or two, so the range doesn't drop as much due to the increased efficiency. It seems like this 'hits a wall' at roughly 87% SOH: then a lot of us start to notice serious range loss.

LeftieBiker said:

Your lower than expected loss of range is likely due to a common phenomenon: you learn to drive more efficiently in the first year or two, so the range doesn't drop as much due to the increased efficiency. It seems like this 'hits a wall' at roughly 87% SOH: then a lot of us start to notice serious range loss.

Click to expand...

I'm at 84% SOH with about 3.5 years of driving (battery is over 4 years old). My commute is 10% neighborhood and 90% interstate with cruise set a constant speed so there isn't much to vary or get more efficient at. When the car was new, on a 30 degree morning , with cruise set at 60mph and using only steering wheel and seat heaters, I'd arrive at work with about 65% battery. 3.5 years later, under the same circumstances, I'm still over 60% (usually 62% or so). I have noticed some range loss but it doesn't seem like 15% range loss is all I am saying.

Did you set the heat and A/C at the same temps when the car was new as you do now? Do you have the tires at the same pressures? Much of what we learn isn't driving style, but simple tips & tricks that make the car more efficient regardless of how you drive it. Just wear-in on the tires and drivetrain is usually good for a couple of percent increase in range. This phenomenon is also noted by automotive testers who keep cars for a year, with ICE vehicles. The fuel economy usually increases a bit after wear-in.

LeftieBiker said:

Did you set the heat and A/C at the same temps when the car was new as you do now? Do you have the tires at the same pressures? Much of what we learn isn't driving style, but simple tips & tricks that make the car more efficient regardless of how you drive it. Just wear-in on the tires and drivetrain is usually good for a couple of percent increase in range. This phenomenon is also noted by automotive testers who keep cars for a year, with ICE vehicles. The fuel economy usually increases a bit after wear-in.

Click to expand...

I don't use the heat in my winter example, only seat and steering wheel heaters. Tires at 38psi as always. I did get new tires in July, but they are the same Ecopias I started with. If the car got a little more efficient after break-in that's great, hopefully that happens for everyone.

LeftieBiker said:

Your lower than expected loss of range is likely due to a common phenomenon: you learn to drive more efficiently in the first year or two, so the range doesn't drop as much due to the increased efficiency. It seems like this 'hits a wall' at roughly 87% SOH: then a lot of us start to notice serious range loss.

Click to expand...

My 2014 LEAF isn't there yet.

Update: Previously I reported a SOH drop from 96.96 to 96.90 over 1200 miles. Now after a week and about 150 miles I plugged in the odb-ii and Leafspy reported a sudden drop to 96.60. I unplugged it and restarted car and it read 96.54. Next morning it was down to 96.38. It's been 3 days and 30 miles since with more drops. After full level 2 charge today it was 95.60. Just powered on car after typing this and now down to 95.56. Who knows what's going on. Suddenly the rate of loss is alarming. Best guess is Leafspy or odb-ii (BAFX) isn't precise, goes through various adjustment periods or something, was overstating SOH for a while. Just turned power on and now it's 95.49. Anyone experience this? if I keep measuring frequently maybe it will drop to zero by next month!

I guess the good news is you appear to have a new, free battery in your future.

Don't sweat over it. SOH will go down and then occasionally go up.

My 2018 WAS purchased in May of 2018. When I got it, it it was showing 98.74% is now showing 96.16% SOH with about 3,000 miles on it. It was a fresh car, not a parking lot queen. It was only on the dealer lot for about month. Based on the logs, I've lost 2.58% in 8 months. So in 10 years I'll be down to 62%. By then I'll be 84 years old (hopefully) and I won't care or won't remember what a GID or SOH is. Still at 62% that's about 100 miles of range. That should be enough to get me to doctor appointments if I still can remember where the doctor is.

My 2015's SOH used to vary up to 1% AT TIMES. When I bought it, it was in dealer inventory for almost a year. It started at 95%, Almost 3 years later it was 85.59%

If you have not already done it, create a dropbox account and have leafspy automatically upload the log files to dropbox. Then you will have a history of every time you used leafspy. I have logs from 2015.

My 2018 WAS purchased in May of 2018. When I got it, it it was showing 98.74% is now showing 96.16% SOH with about 3,000 miles on it. It was a fresh car, not a parking lot queen. It was only on the dealer lot for about month. Based on the logs, I've lost 2.58% in 8 months. So in 10 years I'll be down to 62%.

Click to expand...

I've seen this mistake in accounting two or three times now. You have to count SOH loss from 100%, not from wherever it was when you acquired the car. They should have all started out with at least 99.9% SOH. You have lost about 3.84%, not 2.58%.

Just to add another Data Point for a 2018 Leaf:

My 2018 Leaf is 11 months old, 8,000 miles living in Atlanta GA. SOH 92.18, HX 112.04 Ahr 106.41

No QC charges, mostly charge to 75%. Charge when I'm down to 30% or so. I charge to 100% about once a month. I really baby the battery, charge only early in the morning when it's coolest.

I bought the Leaf before in was delivered to the dealer, so it did not sit on the lot, the SOH was 99.9 when I picked it up.

Like others I've seen the SOH do big drops over a day or two, both winter and summer. I've never seen it go up.

It does seem that, along with the Hx number now being utterly useless, the SOH now only drops, at least under normal conditions.