Am I overthrowing battery degredation.

[markymark]

Hello,

I don't know if I'm overthinking the battery degradation issue. We've taken the plunge on our first EV, an 72 plate ID3 life with 18000 miles on the clock. According to the paperwork in the car, when we test drove it, the battery health was 93%, which I understand from my first post is OK. But I guess im a little concerned about the batteries long-term health after reading various posts on the Internet relating to all makes of EVs about batteries health dropping quickly. I know alot can depend on if the car has done a lot of fast DC charging and / or if it been charged to 100% often. What's your take on it? Thanks. Mark.

[sidehaas]

There are lots of ID cars with well over 100k miles on them now and I've never heard of anyone having very significant problems with degradation. There was a woman on the owner's Facebook group who had done 150k and said she hadn't noticed any change in range at all. There are also plenty of older EVs and none are known to suffer from high degradation apart from Nissan Leafs without battery temperature management. I don't think it's anything to worry about given the current state of your car.

[markymark]

Thanks for that. I think I'm probably just overtaking it because it's our first EV. I didn't know Nissan Leafs didn't have battery heat management.

[Batterdry500]

(Here's a cut and paste of my own views on this from a similar thread....)

To me VW would have thought long and hard before guaranteeing 70% batteries capacity after 8 years or 100k miles...before putting themselves anywhere near being on the hook for a MASSIVE battery recall programme when cars reach that stage.

So my guess is we can expect the vast majority of batteries to land at north of 75%/80% by then and follow a steady trajectory from new to there.

To that end, as owner of a 2.5 year old ID3 with 26k miles I therefore haven't given a second thought to battery degredation.

And to me if your car is 2 years old and at 93% then each year it is 97% of the previous years capacity. This slighlty over simplifies things but you might expect this glidepath based on those numbers.

Year 0 100
Year 1 97
Year 2 93
Year 3 90
Year 4 87
Year 5 84
Year 6 81
Year 7 78
Year 8 75

So you end up 5% above the point the battery warranty kicks in. If it's worse...then your battery warranty kicks in.

I just don't see anything to worry about.

What's more, you can now be careful (if you want) to slow charge, keep it under 80% charge etc etc if you think that might improve the glidepath going forward.

EDIT> or alternatively you could do your best to get the battery under 70% capacity after 8 years and claim a new battery !

[markymark]

Thanks for that. The sliding scale would make sense. My plan is to slow charge the ID3. I can charge the car for free from work on a 7kw charger or there is a 22kw type 2 charger not far from work. But I understand it will only charge at 11kw on AC.

[Batterdry500]

Thanks for that. The sliding scale would make sense. My plan is to slow charge the ID3. I can charge the car for free from work on a 7kw charger or there is a 22kw type 2 charger not far from work.

I used to think that about slow charging. But if you go looking for it you can find an equal number of studies and opinions saying that slow vs fast charging makes little difference to battery life.

Same for charging over 80%.

Lots of people seems to think they know...but my conclusion is that nobody really knows at this stage, only time will tell.

And even if you spent then next 5 years fiddling around with slow chargers you would likely never know if it had had any impact. I mean...how could you ?

I will generally charge to 80% max as it's no hardship, and charge at whatever speed is available and quickest...and always, if I feel like it, put convenience first and not spend any time thinking about battery degredation.

[markymark]

Good point as well.
Does the ID3 cool it's traction battery when it's charging? I understand itncan when its moving but im not sure when its charging. Thanks. Mark.

[Batterdry500]

Good point as well.
Does the ID3 cool it's traction battery when it's charging? I understand itncan when its moving but im not sure when its charging. Thanks. Mark.

Sorry no idea - I think that would fall under 'caring about battery health'....which I don't

Somebody will be able to advise.

[markymark]

Apologies for asking lots of questions. It's my first EV but not my first VW. The ID3 will be my 5th VeeDub in 15 years.

[Batterdry500]

Apologies for asking lots of questions. It's my first EV but not my first VW. The ID3 will be my 5th VeeDub in 15 years.

That's what we are here for I guess. Only had mine a couple of months too and first EV.

[MotMot]

This is the thread from a US based id4 forum you want to go through. Multiple users adding their battery deg data to a google sheet.

https://www.vwidtalk.com/threads/batter ... 9/#replies

[sidehaas]

Good point as well.
Does the ID3 cool it's traction battery when it's charging? I understand itncan when its moving but im not sure when its charging. Thanks. Mark.

It heats or cools the battery as necessary when charging. When you plug in on a rapid, if the battery is cold it will initially heat it, then once it gets hot it starts to cool it, and through a combination of cooling and limiting the charge rate it ensures the temperature stays below a certain value (I can't remember what that is.)

[Batterdry500]

This is the thread from a US based id4 forum you want to go through. Multiple users adding their battery deg data to a google sheet.

https://www.vwidtalk.com/threads/batter ... 9/#replies

The charts are interesting to see.

(Oh no...now I'm interested in battery degredation !)

[Midgex]

Hello,

I don't know if I'm overthinking the battery degradation issue. ...

Worry less about it. The various companies underpromised and overdelivered.

On the cooling of the battery during charging, the heat pump variant takes heat from various components that get warm. So there is a cooling system built in. Whether or not one has the pump.

[sidehaas]

Rich Symons has just put out a really good video showing the battery degradation he has measured using an Aviloo device on 300 cars that he has had through his dealership from 30k to 120k miles (half of them Teslas). I haven't seen this extent of data collected together across different brands before.

The VAG data looks fairly consistent with the data from that from the US ID4 forum and sits in the middle of the other brands (a bit above Tesla, below Merc and Volvo). Although I think comparisons are a bit shaky as can be seen from the Kia/Hyundai data.