Thanks for this very interesting info. It’s curious to see the rapid degradation at first, then the stabilization. I took a screenshot of his sampling. More generally, it’s good news for long-term resale

 

Rapid degradation followed by stabilizing aligns with every other chart that I've seen:

The question is how long the plateau lasts. Everyone also measures against miles driven, when everything I've read says that mileage doesn't really matter, it's a much simpler question of age.

 

I think it is worth noting that there were some software and battery management improvements that were rolled out OTA which may impact the results. The video should be caveated with this. Nonetheless, this is outstanding news for PS2 owners and planning a $10k battery overhaul

 

In fact, I was unaware of this notion of a plateau. Thanks for that. I know that many factors influence battery health. I understand that the impact of using rapid chargers is controversial. Are there any conclusive findings?

 

I know the Leaf had issues with DCFC due to no real ability to cool its battery, but beyond that I don't think there is any definitive evidence of DCFC causing increased degredation. Part of that may also just be timelines - even if DCFC causes increased degredation at the 10-year mark, we would only just be starting to see some real-world data points on that. They only made 2.6k Model S in 2012, so we're still a few years away from starting to see the long-term real-world impact of different driving/charging conditions.

I think what will ultimately shake out is that it's like the "3k mile oil change" - less DCFC is better, 80% battery is better, but at the end of the day plenty of cars make it 150k+ miles doing the manufacturer recommended 10k oil change.

 

This video, taken from another forum topic, is very interesting. It shows that the rapid degradation of the first Nissan Leafs was due to an air-cooled battery pack. We also learn that it's better to use partial recharges on our NMC lithium batteries: “cells operating in a range of 83% to 63% at ambient temperature showed ”almost no degradation“ after 6 and a half years, simulating 4 million kilometers”.

 

Interesting that they say keeping it between 80% and 60% is the 'sweet spot'. Conventional wisdom has been to keep it as close to 50% as possible - which is what I've let mine sit at, generally speaking. Maybe I should bump that up to 60%.

Here's another interesting one I've read recently:

Science Says Hard Acceleration Might Be Good For Your EV Battery

A new study has found that the occasional spirited acceleration in an EV is actually good for its long-term battery health.

insideevs.com

I assumed that flooring it with the performance software would probably increase degradation (slightly). Looks like it might actually be the opposite.

 

I recently had my SoH done by polestar.
2.5y old car
22,000km
Always charged with granny or 11kw AC. Kept between 30 and 80%

92% SoH. Not sure how I feel about this tbh. Pretty disappointing.

 

I recently had my SoH done by polestar.
2.5y old car
22,000km
Always charged with granny or 11kw AC. Kept between 30 and 80%

92% SoH. Not sure how I feel about this tbh. Pretty disappointing.

The bulk of decline in BEVs happens in the first two to three years, after which it goes much more slowly for the next six to eight years.

 

Ok, not Polestar, but I was in a rideshare EV in China recently, and it had over 476,000km on the clock and still had over 400km range remaining (can't remember the battery percentage but it wasn't 90%).

I think these batteries will last a long time, and if the car does, I look forward to a battery replacement in 15 years.

 

I think these batteries will last a long time, and if the car does, I look forward to a battery replacement in 15 years.

This is an interesting thing about EVs. If we ignore the battery then the rest of the car should, theorectically, last much longer than an equivalent ICE vehicle due to EVs being inherently mechanically simpler and therefore (hopefully) more reliable.

I don't believe there's much of a market for complete drivetrain replacements in 150-200k mileage ICE vehicles because of the high cost so it has become the norm to just buy a new car instead, at significant expense. But if an EV can have a battery replaced for around £10k (probably less in 10-15 years time) then it makes the alternative of buying a brand new EV for around £60k a somewhat different proposition.

There are non-financial considerations of course; it's nice to have a new car and technology will likely have improved over the 10-15 year lifetime of the current EV, but in terms of basic economics, battery replacement instead of a whole new car might well become a real option in the future.

The basic point about all these sort of discussions and speculations is that ICE vehicles have been around for the best part of 150 years and have evolved amazingly during that time. In contrast, EVs have really only been mainstream for about 20 years so it's reasonable to assume the technology is still in its infancy and who really knows what another 100 years of development will bring?

Interesting times for sure, even if I won't be around to witness it all!

 

Most modern cars are pretty good, the 1 series I owned previously was 20 year old when I finally traded it in and little had went wrong in the 10 years I owned it. It was due another suspension overhaul and the rear subframe and brake lines were getting pretty crusty but my main motivation for trading it was purely that I didn't see the point in investing time and money in big repairs when I didn't see me keeping it another 5-10 years. I imagine that'll be the future for most EVs too, while there might be a few models with known issues with batteries or motors, most will end up scrapped purely because maintenance costs v value.

 

I imagine that'll be the future for most EVs too, while there might be a few models with known issues with batteries or motors, most will end up scrapped purely because maintenance costs v value.

An interesting point, but even increasing maintenance costs can outweight the cost of a new replacement. My son had an immaculate 12 year old Golf GTi and one year the annual MoT test coincided with needing all new brake discs and pad and four new tyres. Obviously a big cost for a 12 year old car but that's the cost of motoring really. So he swallowed the cost and kept the car for another three years.

 

It's also interesting to see the emergence of independent specialist workshops that can work on our batteries at lower cost.

 

The polestar 2 traction battery is made to be modular inside the unit. As far as what I have seen in many videos of PS2 and on eBay. No glue is used to hold battery modules together. The pouch cells in the modules are held by glue. This increases over all vehicle costs when new but decreases repair cost.

 

I have 36700 miles on my 2023 LRDM Performance Pack Polestar 2 and I strictly follow Polestar's "recommended" charge to 90% for daily driving. So far, I have yet to see any drop off in battery storage/performance on my daily 65 mile commute all through the year. I drive mainly highway with the odd trip into Seattle where I'd floor it merging onto highway from ramps etc. Most of my daily recharging is from 65-90% at the end of the day.
Based on what I'm seeing, I see no reason to change anything.

 

Just exceeded 100,000 miles, and do not notice any degradation, at least what I can tell or that would affect my usage of the car.

During the first two years, when I was driving up and down the state (CA) and had the free 2-yrs of Electrify America, I charged 11,067kWh at the fast chargers.

I keep it 90% or below unless necessary, charging now on a L2 at home and vary the charge from 12-48A depending on need -- I try to keep it charging all night so set it as such. But overall don't worry or think much about the battery or charging.

 

Just exceeded 100,000 miles, and do not notice any degradation, at least what I can tell or that would affect my usage of the car.

And that's the really key thing isn't it? I could easily lose 50 miles range from my P2 and it would only rarely affect my use of the car and even then it would just mean another few minutes at a rarely used fast charger.

It's too easy to get obsessed by abstract numbers and lose touch with the reality of how we actually use our cars. But I guess it all started with ICE vehicles and the habit is hard to shake off. I mean, any car that has 300hp must be 'better' than one with only 275hp right? Or being only being able to do 130mph must be 'better' than only being able to do 110mph . . . even though such numbers are practically meaningless for 99.99% of our daily driving.

 

Just bought a 2022 AWD with 8,350 miles on it. As of May 2025, the corporate certification process requires Polestar spaces to confirm BSOH and provide a certificate showing the percentage. The car was at 96%. Degredation is not linear and will peak and plateau as others mentioned. I would not worry about it. We have a 2023 Ford Mach-E with 12k miles on it and the BSOH is at 91.5%. Confirmed both by my Car Scanner app and Ford service. That car sat on a dealer lot for a year before we bought it and was likely stored with the battery at 100%, leading to the degredation. Ford acknowledged is was not normal but would not remedy until a number of 70% was reached under warranty

 

As of May 2025, the corporate certification process requires Polestar spaces to confirm BSOH and provide a certificate showing the percentage.

Where did you get this information? Two weeks ago I picked up a certified 2023 P2 with only 5500 miles, but the BSOH was not included. The certification was completed on 7/15/2025. I asked for the BSOH when I was picking up the car and they said it was not required for the certification and therefore didn't run the battery test on it. They provided me with the CPO Inspection Checklist and at the top it states "Version 3.0, Issued date: 4/5/2025". Perhaps they used an older template when certifying it and not a newer one that includes the BSOH.

 

My advice for people concerned about long-term battery health is simple: don't think about it. It's not going to be a problem with an EV made in the last 10 years. You're more likely to have a single cell fail, and those can be individually swapped. If, after a decade of ownership, you want more capacity, history has shown there will be options for aftermarket upgraded packs (see: BMW i3s from 2014 getting new packs from China that have triple the original capacity). Heck, you could probably upgrade an early-model P2 with a pack pulled from a newer vehicle (they're $5k on eBay right now). There's already instructions on VIDA on how to make the software changes an old car handle newer-chemistry cells if they're replaced.

The things that will degrade Lithium-Ion batteries faster:
High temperatures
Charging to 100% and leaving it there
Discharging to 0% and leaving it there

These aren't an issue for regular people.

High pack temps are a non-issue in EVs due to them all having aggressive thermal management systems. Even if I'm only charging at 50kW in the springtime, come back after 20 minutes and those fans will be pushing so much air. Originally everyone thought that frequently fast-charging EVs would lead to faster cell degradation due to increased current, but over a decade of real-world experience has shown that any differences are marginal at best.
Charging to 100% is infrequent for most, and even then, you'd need to leave it there for a long time to have any effect. This guidance is primarily for people who charge at home, given that most people only will use 20-30% of their battery capacity daily then plug in at night, so there's much more wall-clock time that they could sit at 100%.
Discharging to 0% can kill a battery pack, so just… don't drain it then go on a monthlong holiday.

Some guesses about incorrect battery lore:
Nissan took a gamble on passive-cooled batteries in 1st-gen Leafs, and that didn't work out. They were the first mass-market EVs, so they had the first news articles about EVs with battery problems.
Conflating Lithium batteries with NiMH/NiCad. Your dad's power drill needed to be fully discharged/recharged to avoid the "memory effect". Their Lead-acid trolling motor battery couldn't be discharged beyond 50% or else you'd wreck the capacity.
Smartphone batteries – they usually have different cell chemistry to maximize volumetric capacity at the expense of long-term durability. They're charged to 100%/discharged to 0% on an almost-daily basis, and don't have an active thermal control system to keep the batteries cool when they're charging/left baking in direct sunlight

 

Had my first service yesterday (30,000km service, at my house). Have owned the car since Halloween. Asked the technician to check battery SoH--it was at 99%. I was expecting one or two percentage points lower, so I'm pretty happy.

(Polestar 2, 2025, LRSM with Climate Pack)

 

My 2024 CPO i got in Dec 2024 / 7500km on odom, included the battery health in the checklist, it was at 99%

 

Had my first service yesterday (30,000km service, at my house). Have owned the car since Halloween. Asked the technician to check battery SoH--it was at 99%. I was expecting one or two percentage points lower, so I'm pretty happy.

(Polestar 2, 2025, LRSM with Climate Pack)

My 2024 CPO i got in Dec 2024 / 7500km on odom, included the battery health in the checklist, it was at 99%

I suspect they are using misleading calculation to get the 99%.

Me and my friends got some numbers for SoH for our P*2s using these methods:

calculation using charge delivered by charger and SoC change for the charging session;​

calculation using trip computer distance and trip consumption, then use car reported SoC change to verify​

OrBit reported value​

Both our cars (and many others in this forum) falls around 92~95%. - My car had ~35k km on the odo while his had >80k

Why do I call the numbers they gave you misleading?
- If they did the calculation based on useable instead of nominal then it all lines up. Example(assuming 78kWh pack): 99% * 75 / 78 = 95.19%. Personally this number would make more sense (especially for Ovation's car). However when the car calculates SoC / battery reserve etc it does use the hidden 3kWh. It's not "useable" by the normal sense but it is (and should be) there, instead of being used to trick buyers thinking the battery is "healthier" than it actually is.


However I 100% agree with the view of Just don't care about it. Unless you use your car like a crazy person* the battery will outlast other things in the car.

*crazy person: someone who leaves their car @ 100% or 0% for prolonged period of time, and only start charging when battery is <8% and don't unplug until >98%.

 

Great info and this makes sense. I have a 2022 P2 and a 2023 Mustang Mach-E. The Mach-E is capable of delivering the SOH through the OBD2 port with the Car Scanner app I use on my phone. It matches exactly Ford's test results when my car was in for service. The only difference is the dealer's software provides very granular level detail such as voltage variance between individual cells. An interesting report and very detailed but the car provided overall BSOH percentage number result matched the same.

 

My advice for people concerned about long-term battery health is simple: don't think about it.

This is the best advice I have read on here in a long time. I have much more important things to use my brain cells on. 🤣

 

What's kind of missing here is that any direct vehicle reported SoH is just an estimate, unless you keep doing deep discharge and charge cycles.

The only way to get a precise number is to charge up to 100%, discharge to 0, and then back up to 100% again. If you just keep on charging/discharging say within a 20-80% range the vehicle's battery management system is likely slowly drifting away from the real SoH. Same with trying to derive the SoH from e.g. a 20% discharge/charge cycle - you will only get the numbers that the vehicle thinks is 20% of the battery capacity.

BTW no judgement here on why you want to know it, or why you better want to ignore it When I had a Tesla I tried to track it frequently and even ran the diagnostic in the 'secret' menu which does do a full discharge/charge cycle.