Eletric cars are they worth it - do you have one

born_again

Brie said:

might stretch to £5k for a cheap runabout.  I don't think a EV is possible at that price.  

It can be done. & a further vid this guy is doing 1k a month in this car now.
He got set a challenge to buy a sub £5K car with the same range as when new.

https://youtu.be/h4hPkfn6FwE?si=wlii4XbndseXkt_y

Grumpy_chap

Goudy said:

If say a car's anti perforation warranty was 8 years but only the top 2/3rds was covered in the small print, I'm sure some would be fooled and others use the 8 years to qualify a point of view or decision. It's still partially worthless.

But, the anti-perforation warranties are also stacked full of small print.
Typically covers perforation from inside to outside only, excludes exposed areas (such as inner wheel arches) and requires full perforation to have occurred before the corrosion is deemed a warranty matter and only any cover at all if there has been an annual inspection by an agent of the manufacturer (even excluding the annual service by a non-franchise Dealer).
The probability of a successful claim is very slight.

Martyn1981

Grumpy_chap said:

Goudy said:

If say a car's anti perforation warranty was 8 years but only the top 2/3rds was covered in the small print, I'm sure some would be fooled and others use the 8 years to qualify a point of view or decision. It's still partially worthless.

But, the anti-perforation warranties are also stacked full of small print.
Typically covers perforation from inside to outside only, excludes exposed areas (such as inner wheel arches) and requires full perforation to have occurred before the corrosion is deemed a warranty matter and only any cover at all if there has been an annual inspection by an agent of the manufacturer (even excluding the annual service by a non-franchise Dealer).
The probability of a successful claim is very slight.

Hiya GC, thought you might be interested in some actual data on the Tesla model 3 that's just come out, since you have one. The study of over 6k cars was actually to see if there was any difference in battery degradation if the cars were mostly rapid charged v's mostly slow charged. But the results are still useful, just from a battery degradation over time POV.

[Worth noting however, that the lack of difference, is largely put down to Tesla's ability to pre-condition batteries as you approach the supercharger location. So may not apply to all other makes of BEV.]



From the trend lines, we can see that degradation slows over time, and is significantly reduced around the 90% mark. Looks (to me) as if the degradation then slows to 1-2% per 1,000 days after that. So hitting 80% will take a significant number of years, perhaps 15 more?

The chart for the Model Y looks to be very similar, but less vehicles tested, and of course they haven't been out for as many years as the TM3.

Also, probably worth noting that the base TM3's are now using LFP batts, which as others have mentioned, should be good for 'more abuse'. And that base vehicle with an EV-Database estimated real range of 250 miles, is rumoured to be getting a 10% larger battery, under the Highland refresh, due out in the next month or two.

Full Speed Ahead: EV Study Reveals Impacts of Fast Charging

Goudy

That's interesting but there seems to be a variable missing.
Mileage or some other usage metric. 

How many fast charges?
How many rare fast charges?
What is frequent?

I would have thought mileage in a study like this would be fairly important to get any worthwhile results.
The more miles the more discharges and charges and obviously the same could be said for smaller batteries over similar mileages.

Time in either minutes, days, months, years isn't that useful to a report like this.
Battery age? Should it not be use and the metric mileage or perhaps number of discharges and charges?

In a 2000 days of what does it lose X% capacity.
2000 days of no charging, 1 charge a month, 3 charges a day, what?

Anyone could say a tank of petrol or diesel lasts them three months if they don't do many miles, yet someone doing more miles it might only last them a day or less.

Again, it's another slack attempt to back up a piece of technology people are obviously worried about and to anyone bothered it study it, it's failing.
 

sevenhills

WellKnownSid said:

Nissan data suggests a 22 year usable lifetime on the Leaf.

Lots of 'facts' and figures being posted, how long do ICE vehicles stay roadworthy? We see threads about timing belts etc, I am guessing many cars won't last longer than 10 years, due to breakdowns and accidents.

Grumpy_chap

Martyn1981 said:

From the trend lines, we can see that degradation slows over time, and is significantly reduced around the 90% mark. Looks (to me) as if the degradation then slows to 1-2% per 1,000 days after that. 

Thanks @Martyn1981 .

As @Goudy has noted and commented, the degradation mapped against days seems, at initial review at least, an illogical metric.  You really would think that "number of charges" or "miles" would be a more appropriate metric than "days".

Maybe, however, days is an appropriate metric and thee effect on battery capacity is predominantly associated with age or environmental (temperature) exposure rather than care, use, abuse.  I don't suppose Tesla had a control batch of batteries held simply stored on the shelf for five years against which to compare these results.

CliveOfIndia

sevenhills said:

WellKnownSid said:

Nissan data suggests a 22 year usable lifetime on the Leaf.

Lots of 'facts' and figures being posted, how long do ICE vehicles stay roadworthy? We see threads about timing belts etc, I am guessing many cars won't last longer than 10 years, due to breakdowns and accidents.

I've always bought "old" cars.  If they're looked after, they will last for decades.  The most expensive car I ever bought was 8 years old, I've done about 90,000 miles in it and - touch wood - it's still going strong, having just ticked over to 150,000 miles.  My previous car was on 180K when I sold it on (timing belt changed at recommended intervals by a local mechanic for a very reasonable price).

I hate to disagree with you, but with a bit of routine (and relatively cheap) maintenance, 10 years for an ICE car is pretty young in my view.

I guess it's a different calculation if you're someone who always buys brand-new cars and changes them every three years - but the so-called "bangernomics" approach has some merits.  Out of interest I calculated the overall cost of the cars I've had (yep, I keep a spreadsheet, 'cos I'm sad like that), and there's no way a new car (of whatever description) could come close to the economy I've had over the last few cars in my lifetime.

Martyn1981

Grumpy_chap said:

Martyn1981 said:

From the trend lines, we can see that degradation slows over time, and is significantly reduced around the 90% mark. Looks (to me) as if the degradation then slows to 1-2% per 1,000 days after that. 

Thanks @Martyn1981 .

As @Goudy has noted and commented, the degradation mapped against days seems, at initial review at least, an illogical metric.  You really would think that "number of charges" or "miles" would be a more appropriate metric than "days".

Maybe, however, days is an appropriate metric and thee effect on battery capacity is predominantly associated with age or environmental (temperature) exposure rather than care, use, abuse.  I don't suppose Tesla had a control batch of batteries held simply stored on the shelf for five years against which to compare these results.

Thought you'd like it, as I would suggest it's a common fear that ultra-rapid charging will cause higher degradation over time. So great to have that concern lifted. Now there's just the issue of higher charges, but even there I may have some extra good news for you:

Prior to the invasion of Ukraine, the charging rates at Tesla SC stations tended to vary from 20p/kWh through 25p and possibly 30p for high demand locations. Back then I'd suggest domestic tariffs were about 15p-18p/kWh, I was paying 17p/kWh day rate, with cheaper E7 at night. When you take into account the VAT rates, 5% for domestic, but 20% for chargers, then the prices aren't too dissimilar. Maybe the Gov will allow the lower VAT rate to be applied. And on top of that, the Tesla charge (but not others I believe) is on the amount of leccy that reaches the battery, so excludes charging losses, which at home might be 5% to 10%.



Yep, the lifespan of a battery is both use and age, after all, we keep being told the batteries will need to be replaced after Xyrs .... .  But of course we also have the other data on Tesla's by mileage, provided by Tesla in their annual impact study reports, and also many years ago, by a survey carried out by Ben Sullins of the then Teslanomics site.

So all data seems to show that degradation for these Tesla batteries is fine, over a large number of miles, and/or years.

You may also have noted that whilst much spin and interpretation of words (such as warranties) has been used to question the data provided, and the real life experiences of us BEV'ers, no actual report has been cited to support the negative claims (assumptions?)

It very much reminds me of the negativity being pushed against PV panels back around 2010-15, with claims from the naysayers that they would degrade at about 2% pa. But 12yrs in, now, for me, I still can't spot any negative trend in my annual generation figures. Suggesting any loss that may exist, would have to be 2% or 3% or less in total, otherwise it would show as a trend line.


Of course most of the degradation arguments are moot, since they largely arose due to losses in the early (2011-14 (I think)) Nissan Leaf's, whilst Nissan's later batteries aren't as bad, and keep improving. Batteries keep improving each year, as does their managment. Plus, with the massive rollout now of LFP, we can expect further improvements for those vehicles.

In fact, whilst discussions going back over the last 3+yrs talked about the possibility that batteries could now, or soon, manage 500k miles, possibly 1m - it's now being discussed on a far higher level, for batteries that are currently being researched and developed, with tests now suggesting the possibility of 4m miles ....... ok, that's probably beyond anything we would actually ever need, but at least it will help to end the degradation claims that keep popping up.

Tesla and Jeff Dahn’s million-mile battery needs a name upgrade

Among the designs and chemistries, LFP (lithium iron phosphate) and NMC (nickel manganese cobalt) are two that were discussed during the interview. While LFP is considered second-best, NMC has taken the top spot, according to Metzger.

Initially, it was capable of thousands of cycles, but it now has the capacity to run 19,500 cycles and counting.

“Each cycle is 300 kilometers. So, if it were at 20,000 cycles, it would be 6 million kilometers,” Metzger said in the interview.

6 million kilometers is equal to 3,728,227 miles. The technology has nearly quadrupled in the past few years.

ComicGeek

Martyn1981 said:

Grumpy_chap said:

Martyn1981 said:

From the trend lines, we can see that degradation slows over time, and is significantly reduced around the 90% mark. Looks (to me) as if the degradation then slows to 1-2% per 1,000 days after that. 

Thanks @Martyn1981 .

As @Goudy has noted and commented, the degradation mapped against days seems, at initial review at least, an illogical metric.  You really would think that "number of charges" or "miles" would be a more appropriate metric than "days".

Maybe, however, days is an appropriate metric and thee effect on battery capacity is predominantly associated with age or environmental (temperature) exposure rather than care, use, abuse.  I don't suppose Tesla had a control batch of batteries held simply stored on the shelf for five years against which to compare these results.

It very much reminds me of the negativity being pushed against PV panels back around 2010-15, with claims from the naysayers that they would degrade at about 2% pa. But 12yrs in, now, for me, I still can't spot any negative trend in my annual generation figures. Suggesting any loss that may exist, would have to be 2% or 3% or less in total, otherwise it would show as a trend line.

Very difficult to assess outside of a test centre though. There were 15% more hours of sunshine in London in 2022 than 2021 for example, I don't know how you would adjust for that in the real world to really assess the system degradation. And how much any dust/bird poo is affecting panel output rather than degradation. May 2020 was a cracking month for PV generation but really not possible to directly compare two different days of output.

I have noticed that in late April/early May when my 12 year old system is at its peak, it reaches the 4 kW limit of my inverter fewer hours than it used to. But how that compares against the 20 year warranty I have for the panels I have absolutely no way of knowing.

To be honest, I'm more concerned about the effect of extreme heat on PV generation though, as my system output is noticeably reduced by around 25% on really hot days. So 2 identical cloudless summer days can have significantly different yields depending on air/roof temperatures and wind effect (to remove excess heat). 

In terms of batteries for cars, we just don't have enough real world data to know for sure. I'm sure manufacturers have picked their 70% in 8 years as being a very safe level for them, so statistically most EVs should comfortably exceed this. I'm a big fan of batteries (with 2 EVs and a large home battery system) but it is easier taking risks with my company's money than my own! Not sure I would buy 2 EVs personally at the moment.

Martyn1981

ComicGeek said:

Martyn1981 said:

Grumpy_chap said:

Martyn1981 said:

From the trend lines, we can see that degradation slows over time, and is significantly reduced around the 90% mark. Looks (to me) as if the degradation then slows to 1-2% per 1,000 days after that. 

Thanks @Martyn1981 .

As @Goudy has noted and commented, the degradation mapped against days seems, at initial review at least, an illogical metric.  You really would think that "number of charges" or "miles" would be a more appropriate metric than "days".

Maybe, however, days is an appropriate metric and thee effect on battery capacity is predominantly associated with age or environmental (temperature) exposure rather than care, use, abuse.  I don't suppose Tesla had a control batch of batteries held simply stored on the shelf for five years against which to compare these results.

It very much reminds me of the negativity being pushed against PV panels back around 2010-15, with claims from the naysayers that they would degrade at about 2% pa. But 12yrs in, now, for me, I still can't spot any negative trend in my annual generation figures. Suggesting any loss that may exist, would have to be 2% or 3% or less in total, otherwise it would show as a trend line.

Very difficult to assess outside of a test centre though. There were 15% more hours of sunshine in London in 2022 than 2021 for example, I don't know how you would adjust for that in the real world to really assess the system degradation. And how much any dust/bird poo is affecting panel output rather than degradation. May 2020 was a cracking month for PV generation but really not possible to directly compare two different days of output.

I have noticed that in late April/early May when my 12 year old system is at its peak, it reaches the 4 kW limit of my inverter fewer hours than it used to. But how that compares against the 20 year warranty I have for the panels I have absolutely no way of knowing.

To be honest, I'm more concerned about the effect of extreme heat on PV generation though, as my system output is noticeably reduced by around 25% on really hot days. So 2 identical cloudless summer days can have significantly different yields depending on air/roof temperatures and wind effect (to remove excess heat). 

In terms of batteries for cars, we just don't have enough real world data to know for sure. I'm sure manufacturers have picked their 70% in 8 years as being a very safe level for them, so statistically most EVs should comfortably exceed this. I'm a big fan of batteries (with 2 EVs and a large home battery system) but it is easier taking risks with my company's money than my own! Not sure I would buy 2 EVs personally at the moment.

Hi, if you want a tip for comparing annual figures, then you can use the Met Office anomaly maps. After comparing annual generation to the annual estimates from PVGIS, and reviewing against the anomaly maps, you should be able to see a reasonable match. For instance the map suggests for my location, that 2022 was around 105%-110% of average, and we got 107% of target. My worst full year was 2017, with 99% of target, the anomaly maps suggest 95%-105%. July 2023 (August not available yet) was 93% of target, and the maps suggest 70%-90%, so did OK there.

Haven't yet noticed any decline, which I'm really surprised at. Have asked other PV'ers, and on other sites, and so far, degradation seems negligible. One person with thin film solar panels (CIGS), installed 12(ish) years ago, has seen about a 5% reduction (in total), but that too is far below expectations.

Detailed stuidy in 2011, suggested a 0.36% pa reduction for mono-silicon panels post 2000, the pre 2000 estimate was 0.47%, so looks like the technology kept improving. The study suggests for the CIGS panels a post 2000 degardation rate of ~1%pa, so ~5% over 12yrs is fine.

Ediit - Forgot to say, that the impact of temp on performance of PV varies by panel type, but is typically around 1% for each 2.5C change from ~20C. So panels in direct sun, for example, that heat up by 50C, would see a 20% loss in generation. So as you say, a still hot day, has a large impact on generation. That's actually why countries with far better sunshine levels than the UK, don't see vastly higher annual generation. North Africa, Australia etc, may get 80% more generation, around 1,800kWh/kWp v's a good location in the UK at 1,000 to 1,100.


Yep, still early days for BEV batteries, but the numbers for Tesla (going back up to 10yrs) appear to be fine, or better than expected. Data for other makes is more limited, as the fleets aren't as large/old.