A recent decline

Hi Leafers,
I purchased my Leaf in Nov. of 2015. It was off lease from a cool climate (Chicago) and only had 14K miles on it. I was very pleased with the early readings I was getting from LeafSpy. Here's a sampling from Jan (Date/AHr/SOH/Hx):



So you can see in the cold weather I was getting almost unbelievable readings for a 2.5 year old battery.

Feb/March, I started to see a decline from the 98-100% SOH. Nothing drastic, but noticeable:


Now May/June and the decline is starting to really bother me.


On the one hand, I know that keeping a 3-year-old battery in the upper 90s for SOH is unrealistic (I think), but I'm worried maybe something I'm doing is causing the decline.

I do live in NC, and it is a warm spring. We have already seen temps in the 90s here. For a while I was charging at work during the day. Lately I have been reserving charging for overnight in my garage. It is parked in the sun for most of the day though.

I drive in B-Eco. I charge to 80% most nights (though now that my kids are out of school and I'm really just driving back and forth to work I'm only charging every 2 or 3 days, but that is very recently new and not factored at all into these numbers).

Should I expect the rate of loss in my total AHr's to continue to decline? Will it climb back up in cooler weather? What could explain this rapid decline? Is this even a rapid decline? I'm still not sure how my battery was reading what it did back in January.

At first I would charge up to 100% and see 101miles on the dash. Even though that was unrealistic, it is a little surprising now to charge up to 100% and only see 83 or so.

NC is good for 6% to 7% a year decline, just like TN. Unless you are losing more than that per year I wouldn't call it unusual.

I bought a 2012 SL from NC last year at 83% SOH and hit the 76% SOH within less than a week from the one year mark. And most of that was in the 3 hottest months with very little action in the winter (but still downhill all winter). I think I lost 3-4% SOH in the summer and 1% the month before and after summer, and then 1% spread out over the remaining 5-6 months.

dhanson865 said:

It's going to be below freezing here again tomorrow night.

I'm still losing aHr and Hx. Can I look forward to little or no degradation this winter or will I greet spring with noticeably less capacity than I start winter with?

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Shortly after I bought the car used the stats were:

2015 May 15 54.664 Ahr, 83%SOH, 68.01 Hx

The quote above was from Nov 21 2015 which was one month before start of winter my stats were:

2015 Nov 21 51.463 AHr, 78% SOH, 60.10 Hx (lost 2nd bar around here)
2015 Dec 21 51.345 AHr, 78% SOH, 59.85 Hx (roughly first day of winter)
2016 Jan 21 51.194 AHr, 78% SOH, 59.49 Hx
2016 Feb 21 50.965 AHr, 77% SOH, 58.96 Hx
2016 Mar 21 50.735 AHr, 77% SOH, 58.52 Hx (roughly first day of spring)
2016 Arp 21 50.617 AHr, 77% SOH, 58.14 Hx
2017 May 21 50.335 Ahr, 76% SOH, 57.45 Hx

So even with winter driving and no heat exposure of any significance AHr, SOH, and Hx all dropped noticeably during the coldest of winter months.

I have about 5 weeks to go before I can give a one year / 12 month comparison.

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OK, so I now have the one year data (and I've edited in the April and May data in the quote above).

dhanson865 May 16th 2015 leafspy stats are 54.664 AHr, 83% SOH, 68.01 Hx, 38,499 miles
dhanson865 May 16th 2016 leafspy stats are 50.361 Ahr, 76% SOH, 57.55 Hx, 48,329 miles

So I'm getting about 10,000 miles a year and I lost about 7% of my range in the last year. I should lose my 3rd bar this summer.

Warranty will run out this winter, I won't lose bar 4 until next summer. No free pack for this car.

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I think you'll find it's all downhill from here on, no more rising SOH like you got for a few days/weeks back in Jan.

Try doing a couple of 100% charges, to equalize the cells. Drive the car as soon as possible after the charge lights all go off. Then check it again.

Yeah, it looks like it's all decline. I did some 100% charges, drove it right away. No change and in fact the decline continues.

My latest numbers:

AHr; 59.887
SOH: 91%
Hx: 89.51

I think my best course of action at this point is to stop obsessing over it. Clearly it isn't going to rebound. It may slow in the cooler weather. Based on my driving habits, I don't anticipate the car ever getting to the point that it doesn't suffice for my commute. I drive 10-30 miles a day and can charge both at home and at work.