BEVs deals and information

JKenH

ABrass wrote: »

Nope, my point is that Joe's wrong. He claimed that calendar aging increases dramatically over time when the reverse is true, it tapers off over time. You helpfully found a source that agreed with me, and your Google link take you to multiple other sources that support it.

Joe might have been aware of more sources that contradicted yours, but it seems he has word of mouth and that's it.

Now if you think Joe is right, your examples are wrong, and I've missed something then please chip in.

I apologise if we are at cross purposes and what you say above may be correct but my earlier post #502 was intended as a response to your comment in post #501 “The information I can find points almost entirely at use rather than any passive degredation.” My later post #509 was a follow up to that.

I hope that helps.

Ken

ABrass

It does shed light. I should have said that use is the predominant cause of degredation, in particular the effect of use if at an elevated temperature. Which would have helped avoid cross purposes. The info you linked to on passive degredation was interesting.

...Which all goes to show why cooling systems are so important on EVs.

silverwhistle

ABrass wrote: »

22kw charge rate shouldn't be described as fast anymore. 50kw maybe but I'd hold out for 100kw as a minimum to be classed as 'fast'.

It's a significant difference. I've been looking at having a try of EVEZY next year, and when you look at their lower end three models Leaf, Ioniq and Zoe the range of the Ioniq is less, but its faster charging makes it more useful for longer trips.



If you're only charging at home that may not be significant, but as more households become single vehicle EV only it will take on more importance.

Martyn1981

silverwhistle wrote: »

It's a significant difference. I've been looking at having a try of EVEZY next year, and when you look at their lower end three models Leaf, Ioniq and Zoe the range of the Ioniq is less, but its faster charging makes it more useful for longer trips.



If you're only charging at home that may not be significant, but as more households become single vehicle EV only it will take on more importance.

That's why I think the Tesla Supercharger upgrade to 250kW is so important, that would allow charging the middle 150 miles of the 250 mile TM3 SR+ in approx 9mins. So on a long journey you could set off and drive 200 miles, then have a 9min reststop, followed by another every 150 miles. Sounds like a reasonable/sensible drive, and I'm betting most new BEV's will be have this potential in 5yrs or so [or a proportional potential, depending on battery size].

joefizz

ABrass wrote: »

Nope, my point is that Joe's wrong. He claimed that calendar aging increases dramatically over time when the reverse is true,

joefizz wrote: »

Martyn, agree we are going round in circles.
Battery degradation is a function of time (amongst other things). Its a rapid drop off after a certain period and accelerates after a certain percentage useful. (becomes difficult to manage below a certain percentage).

If you read my actual words, the two things were in different sentences. I said that aging amongst other things degrades batteries. I then said battery degradation accelerates after a certain time/level. I was talking about battery degradation, Id already stated in an earlier post a lot of the contributory factors.



I never stated that calendar aging increases dramatically over time, thats your inference from my two separate sentences. I accept your apology for misrepresenting my words ;-)



Thats the problem when you dont look at data and papers published by places like ORNL (yes I have had conversations with 'battery guys' from there. Learned more in a 2 hour conversation than I ever did reading stuff online and thats with 2 degrees in engineering - as I posted over on the battery thread about current sodium battery difficulties).


Going back to the general point, people use terms like SOC when thats not a unit of measurement. In fact its not defined at all and varies per description. The most common usage is available capacity per rated value. Installed value is generally higher (tolerances and engineering overhead) so for the first whatever you want to measure SOC will be close to 100% as that overhead is degraded away.


Very rarely is SOH (state of health) used, and rarely outside scientific publications (like those from ORNL, Stanford, umich) are actual recorded scientific units of measurement used.
Anyone wanting to look at battery degradation from any perspective (and it varies with battery chemistry) can look up these publications and have a look through themselves rather than relying on blogs, pr, marketing and other such stuff.


Even comparing years of cars (leaf, model 3) is difficult because sometimes batteries are experimental and pushed out to make a date (leaf) or as time progresses the push is on for profitability so cheaper chemistry is used (model 3 if the reports about chinese made ones are to be believed).

It makes sense to take a hit on your first run of any production to either get it to market and get it out there and let your users do the beta testing (microsoft got away with this for years) or run at a loss on your first couple of years and make it bomb proof then look to recoup development cost with cheaper alternatives when you realise you are over engineering the product but have a good name for a good product.

almillar

ABrass:

22kw charge rate shouldn't be described as fast anymore. 50kw maybe but I'd hold out for 100kw as a minimum to be classed as 'fast'.

Naming these speeds is a nightmare, everyone calls the same speed different things. I would call above 7kW 'fast', and 50kw upwards 'rapid' (rapid is faster than fast, see?!!), and those are fixed. I know rapid charging speeds will go up, for cars and chargers, but I don't think we should keep renaming them as speeds go up - they're already a mess! In terms of 'destination' charging (which we can class as AC, using the car's on board charger, we're pretty much maxxing out at 7kW, or 22kw if we're lucky. 22kW is a good cut off, because that's the cut off for AC only chargers. Rapids are DC, often with AC43, but a 'fast' charger is a small box (with no AC/DC converter) and a 'rapid' is a big box, which does the AC/DC conversion. I think that's a good way to differentiate. So in my book 50kW will always be rapid, even when 'rapider' speeds come along. Just use the number!

almillar

Very rarely is SOH (state of health) used, and rarely outside scientific publications (like those from ORNL, Stanford, umich) are actual recorded scientific units of measurement used.

Can ZE, the app that uses OBD data for Zoe, uses this. That SOH at 105% is what I was talking about earlier, not SOC. LeafSpy does similar, as does the Soul EV app, the name of which I can't remember...

joefizz

almillar wrote: »

Can ZE, the app that uses OBD data for Zoe, uses this. That SOH at 105% is what I was talking about earlier, not SOC. LeafSpy does similar, as does the Soul EV app, the name of which I can't remember...

Yeah, its something Im looking into for the home batteries, they struggled to get over 96% reported in September and charging from 96 to 99 (topped out) took ages.
Although I said over in the battery thread I wasnt going to look at the engineering port, I might use it to record the raw data and chart that whenever I get back to full charging some time in March.
I dropped the lower soc limit to 15% a couple of weeks ago and the reported SOC is now all over the place at cut off, from 11% to 17% so that does concern me a little so will bump it up again to 20% if we ever get a sunny day again...
Should really be posting this on the home battery thread but its all sort of related...

1961Nick

joefizz wrote: »

Yeah, its something Im looking into for the home batteries, they struggled to get over 96% reported in September and charging from 96 to 99 (topped out) took ages.
Although I said over in the battery thread I wasnt going to look at the engineering port, I might use it to record the raw data and chart that whenever I get back to full charging some time in March.
I dropped the lower soc limit to 15% a couple of weeks ago and the reported SOC is now all over the place at cut off, from 11% to 17% so that does concern me a little so will bump it up again to 20% if we ever get a sunny day again...
Should really be posting this on the home battery thread but its all sort of related...

Mine are working fine with a minimum 15% SOC. The cut-off can occasionally be a little higher if either charging or standby occurs between 15% & 17%.

Have you considered giving them a full grid charge & then doing a manual battery balancing?

joefizz

1961Nick wrote: »

Mine are working fine with a minimum 15% SOC. The cut-off can occasionally be a little higher if either charging or standby occurs between 15% & 17%.

Have you considered giving them a full grid charge & then doing a manual battery balancing?

Thanks Nick, thats good to know, did too many things at once, latest firmware and dropped SOC because I could!



Was thinking about the occasional mains charging, particularly as weather patterns this year are a lot different to last. Raining a hell of a lot more and although monthly charge is about on par its very patchy. Will definitely consider it if that keeps up.
One of the things Im considering is charging them all up and then disconnecting the two older ones and just letting them sit over winter and using the two new ones.

Maybe continue this over on the battery thread when I actually get round to doing it ;-)