EV - battery health

RavingMad

Looking on Auto trader, a few dealers would include battery health in their ads. Is this something that can be gotten from the cars settings or do you require manufacturer computers to glean this?

Looking at a 72 plate car and it has 95% health.  Should we need to worry about the life of a car's battery nowadays? Would a car with 50% be sellable? 

MattMattMattUK

RavingMad said:

Looking on Auto trader, a few dealers would include battery health in their ads. Is this something that can be gotten from the cars settings or do you require manufacturer computers to glean this?

It depends on the car, some such as Nissan Leafs show it on the dash at all times, others it is in settings, a few hide it and need a main dealer to show it.

RavingMad said:

Looking at a 72 plate car and it has 95% health. 

Most will state 95% even when the battery health is 99% because generally the system either only reports in 5% increments, or because a 99% measurement would not be totally accurate. 

RavingMad said:

Should we need to worry about the life of a car's battery nowadays? Would a car with 50% be sellable? 

Almost certainly not, even first generation small battery Leafs, which had no battery wear levelling or cooling and have done in excess of 100k miles whilst being deep cycled over more than a decade still have 75-90% battery capacity. Data from Teslas show 90-95% capacity after 150k miles and 85-90%% capacity after 250k miles. A car that only had 50% capacity would still be sellable although it's sales price would reflect that drop in capacity, but I think you would struggle to find any EV that had lost that much capacity, maybe if you bought an original 2010 Nissan Leaf and deep cycled the battery for the next decade you might get it that low, but by that point the car would be 25 years old so little retained value either way.

born_again

RavingMad said:

Looking on Auto trader, a few dealers would include battery health in their ads. Is this something that can be gotten from the cars settings or do you require manufacturer computers to glean this?

Looking at a 72 plate car and it has 95% health.  Should we need to worry about the life of a car's battery nowadays? Would a car with 50% be sellable? 

Check out RSEV on u-tube & 217,000 mile Tesla V 2900 Mile Tesla. What are the differences. Battery test.

95% on a 3 year old car is a good SOH. 
If it dropped 5% each year, how many years before it got to 50%?

Not that it will drop 5% a year.

Ectophile

In many cases, you get the battery state of health by plugging a gadget into the ODB2 port on the car, and then probing it with the right software.  You may need the right combination of ODB2 reader and software to find the SoH for any particular make and model.

Mildly_Miffed

RavingMad said:

Looking on Auto trader, a few dealers would include battery health in their ads. Is this something that can be gotten from the cars settings or do you require manufacturer computers to glean this?

Some cars may have it user-accessible.
Others may require diagnostics - but not necessarily manufacturer.

Would a car with 50% be sellable?

Define "sellable". Everything is "sellable" to somebody - at the right price, even if that buyer is a breaker.

The question is how much cheaper than a fair market price for the same car, but with 90%+... And the answer to that will depend on if we're talking about a car that's low mileage and just out of warranty, or that's a decade or more old and hugely leggy.

born_again

Mildly_Miffed said:

RavingMad said:

Looking on Auto trader, a few dealers would include battery health in their ads. Is this something that can be gotten from the cars settings or do you require manufacturer computers to glean this?

Some cars may have it user-accessible.
Others may require diagnostics - but not necessarily manufacturer.

Would a car with 50% be sellable?

Define "sellable". Everything is "sellable" to somebody - at the right price, even if that buyer is a breaker.

The question is how much cheaper than a fair market price for the same car, but with 90%+... And the answer to that will depend on if we're talking about a car that's low mileage and just out of warranty, or that's a decade or more old and hugely leggy.

Search the video I linked to. That gives a idea how much the £££ between cars of the same age, but miles apart is. 

Mildly_Miffed

Sorry, but there's very few idiot yooochoobers that don't make me want to rip my ears off in seconds.

But if that's the Tesla video you mention (you can link, y'know), then it's entirely likely one that's covered as few as 3k miles in more than a couple of years is going to have degradation actually relating to that lack of use.

Extremely low mileage is VERY rarely good for cars, whatever they are.

Even then, you miss my point - which was "how long is a piece of string, because there's umpty seven different variables".

Herzlos

RavingMad said:

Would a car with 50% be sellable? 

No reason why not. There's likely to be a floor on usable range though but I'd put that at down about 20 miles. If cheap enough then I'd happily have a 2nd car that I could use for all of my local journeys.

Any lower than that and the car will probably be scrap, but the battery is still going to be worth something as a static battery. Even 5kwh usable battery could keep a house running for a while.

Assuming of course someone can't refurbish the battery and put it back in the car. But I suspect for almost anything that isn't an original Leaf the rest of the car will have failed before the battery state is that low.

born_again

Mildly_Miffed said:

Sorry, but there's very few idiot yooochoobers that don't make me want to rip my ears off in seconds.

But if that's the Tesla video you mention (you can link, y'know), then it's entirely likely one that's covered as few as 3k miles in more than a couple of years is going to have degradation actually relating to that lack of use.

Extremely low mileage is VERY rarely good for cars, whatever they are.

Even then, you miss my point - which was "how long is a piece of string, because there's umpty seven different variables".

I know I can link, but it means a big link on the page.

As he is a Dealer, he is far from a idiot 👍

Low mileage on a EV is actually good, as battery has had few charging cycles. 

ElefantEd

I would think that battery degradation would likely follow an exponential/log model rather than a fixed amount per year; so even if you lose 5% in the first year, you'd lose 5% of the remaining 95% the next and so on, so the actual reduction in range gets less and less. Though that might depend on whether the degradation is a question of complete cells failing or if it's a smaller reduction in lots at the same time.

Irregardless, EV batteries seem to be holding up much better than originally anticipated.

MattMattMattUK

ElefantEd said:

I would think that battery degradation would likely follow an exponential/log model rather than a fixed amount per year; so even if you lose 5% in the first year, you'd lose 5% of the remaining 95% the next and so on, so the actual reduction in range gets less and less. Though that might depend on whether the degradation is a question of complete cells failing or if it's a smaller reduction in lots at the same time.

It does not, it depends on too many factors. Charge cycles, temperature, depth of charge and discharge, speed of charging, quality of the batteries, whether it has wear levelling, cooling, etc.

ElefantEd said:

EV batteries seem to be holding up much better than originally anticipated.

They are holding up in line with scientific predictions rather than the scaremongering amongst the anti-EV crowd.