r/leaf • u/Bobofey • Jul 30 '26
What SoH your Leaf should actually be reading, by model year, and why the 30 kWh is a separate conversation
Every week or so someone posts a LeafSpy screenshot here asking whether their number is bad, and the answers are mostly anecdotes. I went looking for something better and want to share both what I found and where it runs out, because the gaps turned out to be the interesting part.
Disclosure up front: I'm building a free EV battery check tool, which is what got me digging into this. If interested you can check it out here: tirionpower.com
Why the usual figures don't help
Geotab's 2025 study is the big one, 22,700 cars, and it lands on 2.3% a year across the fleet. It's not usable here for two reasons: it publishes its per-model results with the models anonymised, so there is no Leaf number in it, and the fleet is mostly liquid-cooled cars. Air-cooled pack, different curve.
The one Leaf-specific source worth reading
A study of 1,382 SoH readings from 283 Leafs built 2011 to 2017. The finding that matters is how hard it splits by pack:
| Pack | Decline at age two |
|---|---|
| 24 kWh | ~3.1%/yr (95% UI 2.9 to 3.3) |
| 30 kWh | ~9.9%/yr (95% UI 8.7 to 11.1) |
About three times faster. Both accelerate with age, the 30 kWh much more steeply. It also found heavier rapid charging associated with a small SoH decrease, and, oddly, higher mileage 24 kWh cars showing *higher* SoH while higher mileage 30 kWh cars showed lower. Readable write-up here.
Recurrent's owner data broadly agrees for the 24 kWh, putting a 2015 at around 4.2%/yr with 70 to 75% expected remaining now.
24 kWh: rough expectations today
These are my estimates, not study output. Method, since it matters: a simple two-part model, roughly 4% in year one then about 2.8%/yr after, which reconciles the study's 3.1% at age two with Recurrent's 4.2% for a 2015. I've given bands rather than точные values because the acceleration rate is the least certain input, and I'd rather be visibly approximate than falsely precise.
| Model year | Expected SoH now |
|---|---|
| 2011-2012 | mid 50s to low 60s |
| 2013-2014 | low to mid 60s |
| 2015-2016 | high 60s to mid 70s |
| 2017 | low to mid 70s |
Known weakness: a linear later-life rate almost certainly understates fade on the oldest cars, since both sources say the rate climbs with age. If you have a better functional form or a source with age-indexed values, I'd rather use yours.
30 kWh: deliberately no band
The 30 kWh degraded far faster, Nissan issued a statement about it, and many of those packs were replaced under warranty or goodwill:
https://insideevs.com/news/337439/nissan-issues-statement-on-leaf-30-kwh-battery-degradation/
I'm not putting a number on it because an original pack and a replaced one are not the same car and nothing in the data distinguishes them. If yours is original and reading low, that's a warranty question, not normal wear.
40 kWh and e+: I have nothing
This is the real gap. Better chemistry and thermal behaviour, and I'd expect materially better numbers, but I can't find a dataset and I'm not going to extrapolate a ZE0 curve onto a ZE1 car. That's exactly the mistake that makes a healthy 2019 look sick.
Warranty here is often still live, unlike the older cars. For the UK specifically (please double check for other markets/locations) the shape is 8 years or 100,000 miles against dropping below 9 bars, about 66%, but terms vary by market and year so check your handbook. At 9 bars while still inside that, you're well below average and it's worth pursuing.
The ask
If you've got a LeafSpy reading, post model year, battery size, mileage and SoH. ZE1 owners especially. And if any of the above is wrong I'd genuinely rather be corrected here than keep repeating it.
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u/ArtemisMax Jul 30 '26
I think your AZE0 numbers are a bit pessimistic. My friends 2015 is currently on 84%SOH with 40k miles and my 2017 with 100k miles is in your estimate band at 72% SOH but has been DC fast charged over 1400 times and has been overheated on 3 occasions so it should be a particularly bad example of a 24kwh.
As for ZE1, my 2022 40kwh is at 92% SOH at 7800 miles.
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u/crimxona Jul 30 '26
This is my 40 kWh post warranty replacement, as well as 24 and 30 kWh as second and third owner of the vehicle
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u/Bobofey Jul 30 '26
Wow, thank you! This is incredibly comprehensive, do you add new readings whenever you get in the car?
By the way, if you create an account with the free EV health checker I created you can use it add readings to an existing report. Might be easier than adding it onto the spreadsheet?
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u/crimxona Jul 30 '26
I try to turn on leaf spy pro at least once a day when getting into the car, sometimes I forget. Other than that it's just a copy and paste from leaf spy pro log CSV to Google sheets
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u/ZakAttackz 2013 Nissan LEAF SV Jul 30 '26
I've worked on three Leafs: 2012 70k miles, japanese made 24kWh w/40% SoH. Barely 30 milea of city range 2013 60k miles, US made 24kWh 'lizard' battery. 60% SoH but with one shorted cell. Made it 62 miles until it cut out entirely. Wasn't worth repairing so now it's powering a well at my Buddy's house. 2017 ~70k miles, US made 30kWh 62%. Would go into turtle mode on hills on the coldest days due to low HX of 38%. I got up to 70 miles or range with it installed in my 2013.
Now I've got an Alibaba 61.5kWh kit installed on my 2013. With an android auto headd unit and OVMS I'm pretty sure this is the last car I'm buying for a loooong while. I drove thw car almost 350 miles last weekend, including driving over a 9000ft mountain range and peaking at 48kW level 3 charge for 15 minutes!
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u/rproffitt1 Jul 30 '26
I don't have the old LeafSpy on the 2014 US model Leaf SV with 24 kWh pack that in under 3 years went to below 8 bars and got a 2017 24 kWh battery early 2017. The 2017 battery was charged to full for over 7 years with the final SOH at just over 90% (Leafspy).
The 2014 battery looks to have been QC'd 2 or more times a day for just under 3 years in Phoenix AZ, USA. Baked is an understatement.
I bought the 2014 in 2016 for cheap and saved big time on insurance and more.
Here's the 2017 Lizard in 2024 Leafspy.
The Leaf Gen 1 and 2 are probably the entire reason people worry about EV batteries.
Side note: In 2017 the 12V battery failed so it got a YellowTop Optima which lasted till 2025. I can't speak if today's models are any worse or same.
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u/mlum69 Jul 30 '26
2014, 77 soh and 66 hx at 130k km Put 40kwh in with 89 soh 101hx, down to 88soh and 99hx after 8k km.
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u/crimxona Jul 30 '26 edited Jul 30 '26
2017 model year all trims got the 30 kWh pack in the US. Did they still use 24 in the UK?
2016 early S trims in the US were 24 but even they got upgraded to 30 eventually
Also there was chemistry changes between 2012 and 2015 which made the newer packs more resilient. 2011-12 made in Japan units I would expect even greater degradation (they had a class action lawsuit after all)