Old electric cars?

Ergates

Grumpy_chap said:

ElefantEd said:

I'd be amazed if you can buy a BEV with only 4 miles worth of battery left. Or even only 20. 

There was a thread recently on here where someone was looking to buy exactly that - a Leaf with 20 mile range.

I don't think anyone in the thread was actually intending to buy one - people were arguing that a car with 20 mile range would still be usable by a lot of people most of the time.

Grumpy_chap

Herzlos said:

It'll continue to tail off gradually until one day you won't be able to make it to the other charger. At 4 miles though, I suspect the car will need to be scrapped for something else, first.

For some perspective, the first Leaf (2010) had a range of about 70 miles and 12 years later the worst ones are down to about 20 miles. So you've probably got another 10 years for it to drop as low as 4.

Genuine question because I truly do not know the answer but I think it is highly relevant to any discussion about battery degradation.

Does the battery continue to fall off gradually, or does it follow and exponential curve and at some point battery degradation becomes very rapid?  Or does the rate of battery degradation slow?

Taking the example of the Leaf, 70 miles at start and 20 miles after 12 years following a slow, mostly linear and fairly flat slope, the loss is 4 miles of range per year.

Will it continue to degrade at the same rate, so 20 mile range takes 4 years (not 10) to have reached a range of 4 miles?  (Reduction of 16 miles in range).

Or will the degradation suddenly increase so it is pot-luck whether the range drops to 4 miles in a few days, or a few months, but you wouldn't be guaranteed years?

Alternatively, does the degradation flatten out in so far as the battery reaches "rock bottom" at some point, so it only ever gets as low as, say,12 miles range but never drops more?

Herzlos

I think it's a fairly slow degradation, and then eventually it'll plummet. But we don't really have old enough electric cars in the real world to see what actually happens as the degradation have been a lot lower than predicted.

https://batteryuniversity.com/article/bu-1003a-battery-aging-in-an-electric-vehicle-ev has some explanations and charts.

ComicGeek

Herzlos said:

I think it's a fairly slow degradation, and then eventually it'll plummet. But we don't really have electric cars in the real world to see what actually happens as the degradation have been a lot lower than predicted.

https://batteryuniversity.com/article/bu-1003a-battery-aging-in-an-electric-vehicle-ev has some explanations and charts.

Really interesting article, which also highlights the impact the charging regime has on degradation. I keep my battery between 40%-80%, have only charged above 80% 2 times for long trips, have only used a rapid charger once (and that at only a rate of 50 kW), and haven't let the battery get below 20% at any point. I'm hoping that this, alongside the active battery management that the EV does automatically, will maintain the range for as long as possible - but looking to keep the car for at least 8 years, so did factor in a 30% degradation when considering range.

It will be interesting to see whether battery degradation is completely to do with how the battery has been treated/abused by previous owners, or whether there's a degree of luck involved. Those EVs on PCP/lease that have been doing regular long range and using rapid chargers should experience the largest degradation - should start seeing data on this in a couple of years time, but apart from Tesla I'm not sure if anyone is actively reviewing this.

photome

Herzlos said:

Jaded2022 said:

Grumpy_chap said:

ElefantEd said:

I'd be amazed if you can buy a BEV with only 4 miles worth of battery left. Or even only 20. 

There was a thread recently on here where someone was looking to buy exactly that - a Leaf with 20 mile range.

What happens over the next few years would it keep going down and then does it bottom out at just a few miles or does it eventually stop working all together?

i have two free chargers a few miles apart I want to use

It'll continue to tail off gradually until one day you won't be able to make it to the other charger. At 4 miles though, I suspect the car will need to be scrapped for something else, first.

For some perspective, the first Leaf (2010) had a range of about 70 miles and 12 years later the worst ones are down to about 20 miles. So you've probably got another 10 years for it to drop as low as 4.

how much would a 12 year old leaf with 20 miles range left cost ?  i couldnt see any below 7k ish on autotrader and the one i saw with range listed said 70 miles

Herzlos

photome said:

Herzlos said:

Jaded2022 said:

Grumpy_chap said:

ElefantEd said:

I'd be amazed if you can buy a BEV with only 4 miles worth of battery left. Or even only 20. 

There was a thread recently on here where someone was looking to buy exactly that - a Leaf with 20 mile range.

What happens over the next few years would it keep going down and then does it bottom out at just a few miles or does it eventually stop working all together?

i have two free chargers a few miles apart I want to use

It'll continue to tail off gradually until one day you won't be able to make it to the other charger. At 4 miles though, I suspect the car will need to be scrapped for something else, first.

For some perspective, the first Leaf (2010) had a range of about 70 miles and 12 years later the worst ones are down to about 20 miles. So you've probably got another 10 years for it to drop as low as 4.

how much would a 12 year old leaf with 20 miles range left cost ?  i couldnt see any below 7k ish on autotrader and the one i saw with range listed said 70 miles

I think at the time of the last discussion about range, there were 2 on autotrader claiming a range of 20ish miles for about £4k, but I'm assuming they've been sold.

They started with a claimed 75 mile range, so I'd be skeptical that a 12 year old one would still manage 70 miles.

Petriix

Not all EV batteries are equal. The earlier Leafs had worse degradation than the more recent ones and other EVs have better thermal management.

In general degradation is slightly higher initially then becomes fairly linear until you get cell failures bringing down the usable capacity dramatically. Without a cell failure it's not likely that a battery would ever have less than 50% of its original capacity within the usable lifetime of the rest of the car. 

The Leaf has a modular battery which enables swapping out the weakest modules with reconditioned ones for a few £hundred apiece. Other EVs vary.

Outside the warranty I'd be far more worried about other expensive parts (like the charger or motor) failing than the battery itself. 

Jaded2022

Herzlos said:

photome said:

Herzlos said:

Jaded2022 said:

Grumpy_chap said:

ElefantEd said:

I'd be amazed if you can buy a BEV with only 4 miles worth of battery left. Or even only 20. 

There was a thread recently on here where someone was looking to buy exactly that - a Leaf with 20 mile range.

What happens over the next few years would it keep going down and then does it bottom out at just a few miles or does it eventually stop working all together?

i have two free chargers a few miles apart I want to use

It'll continue to tail off gradually until one day you won't be able to make it to the other charger. At 4 miles though, I suspect the car will need to be scrapped for something else, first.

For some perspective, the first Leaf (2010) had a range of about 70 miles and 12 years later the worst ones are down to about 20 miles. So you've probably got another 10 years for it to drop as low as 4.

how much would a 12 year old leaf with 20 miles range left cost ?  i couldnt see any below 7k ish on autotrader and the one i saw with range listed said 70 miles

I think at the time of the last discussion about range, there were 2 on autotrader claiming a range of 20ish miles for about £4k, but I'm assuming they've been sold.

They started with a claimed 75 mile range, so I'd be skeptical that a 12 year old one would still manage 70 miles.

That’s what I’m so interested in

time will tell and we should be able to find out by now

the first gen leafs on original battery, how many miles can they do now?

Jaded2022

Herzlos said:

I think it's a fairly slow degradation, and then eventually it'll plummet. But we don't really have old enough electric cars in the real world to see what actually happens as the degradation have been a lot lower than predicted.

https://batteryuniversity.com/article/bu-1003a-battery-aging-in-an-electric-vehicle-ev has some explanations and charts.

When you say plummet will it stop working all together? Or still get a few miles?

prowla

If I get into my petrol car and it says there's 20 miles left, I go straight to the petrol station to fill up.

I can't fathom anybody buying a car with up to 20 miles range.