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Post by crabbyoldgit on Aug 25, 2023 8:38:36 GMT
I come from a physics background ,my school did not do chemistry and batteries are more chemistry than anything else .So my attempts to read and understand have been a bit of a failure, any enlightenment would be interesting and gratefully received.
Been a bit worried about odd comments about and experiences of the performance of aged lithium batteries for sometime now.
1 Car batteries will be considered at end of practical life at around 80% remaining maximum capacity. I thought not for me ,very rarely go more than 60 mile round trip so 30% would serve my purpose. 30% diesel in the tank will get me anywhere I am likely to go.But my experience below would make me wonder if the practical case is not like that at all, infact much much worse.
2 Got an old Dyson hoover, when new I could hoover the whole house at max power ,now I can easily do so at min power. But my max power running at fully charged is 15 seconds and then it's totally flat.Also at min power I better not stop the hoover running as the battery can't provide the start current required to spin up the motor.
So what does this mean for your electric car, well you may have 80% mile range left in your old battery , unless you have to climb a big hill and then 5 miles?
Also my reading shows high charge rates age these batteries faster as does high dis charge rates though not as badly, so much for fast charge stations.
This is why old car batteries are going to be used for grid storage where the discharge rates I guess can be carefully controlled to overcome possible performance issues around aged lithium batteries.
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keitha
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Post by keitha on Aug 25, 2023 9:24:47 GMT
My Batteries on my Solar ( LiFePo ) are guaranteed to 80% over 10 years.
I think like other batteries it's how you treat them.
My late Father in Law had an electric golf bag, when he purchased it the battery was weak, and I got him a new quite expensive replacement, this came with a 4 year guarantee, yet within 6 months was worse than the original, I took it back and replacement provided no questions asked, 6 months later same again and again it was replaced, after a further 5 months he was complaining about the battery deteriorating again. A few days later I was at his house and need to go in the garage and spotted the battery on charge, when I spoke to him he was putting the battery on charge when he got home from golf and leaving it until the next time, usually only a couple of days, but the charger said " do not leave connected when fully charged" .
Lithium batteries work best apparently if you use the mid range so regular charges to 80% then down to 20%, they don't like 100-0-100, indeed some Battery manufacturers tell you to charge to 80% and run down to 20% ( err hang on i paid for 10kWh, not 6)
after 4 years I see no drop off on my solar batteries
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Post by mostlywrong on Aug 25, 2023 11:28:15 GMT
You can replace the battery on the Dyson. IIRC you just need a Philips screwdriver and some patience.
MW
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ethel
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Post by ethel on Aug 25, 2023 21:32:11 GMT
Isn't it lithium batteries that have been in the news recently because of their tendency to burst into flames? If lithium batteries are the future, it sounds like there's quite a way to go yet.
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Post by bracknellboy on Aug 26, 2023 5:09:49 GMT
Isn't it lithium batteries that have been in the news recently because of their tendency to burst into flames? If lithium batteries are the future, it sounds like there's quite a way to go yet. Yes Lithium-Ion batteries do have a built in risk of self ignition. However as with most things, better engineering over time makes for better & safer products, as does better production. Put it this way, the vast majority of people are walking around every day with a Li+ battery in their pocket. Many more are walking round with one in a laptop inside the rucsac on their back. If you are buying a replacement battery for one of your devices, best to try and go the OEM route and not some cheap knock off from some random company on the internet. You may be paying more than you need to, but you are getting the reassurance of a higher quality product.
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Post by bracknellboy on Aug 26, 2023 5:18:52 GMT
The battery on my Dyson failed after a relatively short period. They sent me a new one no quibbles (still in warranty): yes they are simple to change (or are on my particular variant of the good but overpriced cordless vacuum cleaner). In my conversation with them, they did say that for battery longevity, it was better to run it on lower power more often, not default to max power. So if you were previously always running it on max you may very well have inadvertently contributed to it having a shorter lifespan (also plays to keitha's comment about Li+ being better on slower discharge rates). To the other comment about 80% max charge. I noticed when I recently changed Samsung phones that it gave me an option of limiting the maximum charge to 85% to preserve battery lifetime. It might be a relatively new feature or I may have missed it on my old S8. I now have it set by default, and only switch it off when I know I want to get maximum battery charge for some reason. A useful feature. |
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adrianc
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Post by adrianc on Aug 26, 2023 7:55:07 GMT
Isn't it lithium batteries that have been in the news recently because of their tendency to burst into flames? If lithium batteries are the future, it sounds like there's quite a way to go yet. Cheap and nasty charge management seems to be the root cause there. Remember, every laptop and every mobile phone made over the last decade or so has lithium batteries inside. So do toothbrushes, torches, mice and keyboards, vapes, handsfrees - basically, if it's vaguely recent and has a USB charging port, it's almost certainly lithium cells inside... About a quarter of the world's production goes into BEV and HEV vehicles - and that isn't just cars, it's ebikes and all the toot like hoverboards. What proportion catch fire charging? Absolutely minimal. How many lithium battery devices do you have in your house...?
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pikestaff
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Post by pikestaff on Aug 26, 2023 8:20:15 GMT
Isn't it lithium batteries that have been in the news recently because of their tendency to burst into flames? If lithium batteries are the future, it sounds like there's quite a way to go yet. Cheap and nasty charge management seems to be the root cause there. Remember, every laptop and every mobile phone made over the last decade or so has lithium batteries inside. So do toothbrushes, torches, mice and keyboards, vapes, handsfrees - basically, if it's vaguely recent and has a USB charging port, it's almost certainly lithium cells inside... About a quarter of the world's production goes into BEV and HEV vehicles - and that isn't just cars, it's ebikes and all the toot like hoverboards. What proportion catch fire charging? Absolutely minimal [...] Not that rare, unfortunately, see eg www.london-fire.gov.uk/safety/lithium-batteries/charging-electric-bike-and-electric-scooter-lithium-batteries/Chances are most of the fires are with cheap and/or illegal kit bought off the internet, but even reputable brands can fail. My last phone developed a swollen battery, which I only realised when its protective case split. It had always got rather warm when using the fast charger supplied with the phone. These days I use a slower charger unless I really need the speed, which is rare, and if I do need a fast charge I take my phone out of the case to minimise overheating.
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adrianc
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Post by adrianc on Aug 26, 2023 8:28:40 GMT
Cheap and nasty charge management seems to be the root cause there. Remember, every laptop and every mobile phone made over the last decade or so has lithium batteries inside. So do toothbrushes, torches, mice and keyboards, vapes, handsfrees - basically, if it's vaguely recent and has a USB charging port, it's almost certainly lithium cells inside... About a quarter of the world's production goes into BEV and HEV vehicles - and that isn't just cars, it's ebikes and all the toot like hoverboards. What proportion catch fire charging? Absolutely minimal [...] Not that rare, unfortunately, see eg www.london-fire.gov.uk/safety/lithium-batteries/charging-electric-bike-and-electric-scooter-lithium-batteries/120-180 fires annually in a city of 9m population (plus however many million commuters), with how many lithium battery devices...? And that's out of about 20,000 fires the LFB respond to annually... Indeed. Remember that all eScooters are illegal (except for private land use) in the UK, except for the official rental fleets - yet that link points to them being a quarter of all the London fires last year. Oh, absolutely. But I rather suspect that most of those failures are exacerbated by poor charge management.
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keitha
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Post by keitha on Aug 26, 2023 9:04:45 GMT
Cheap and nasty charge management seems to be the root cause there. Remember, every laptop and every mobile phone made over the last decade or so has lithium batteries inside. So do toothbrushes, torches, mice and keyboards, vapes, handsfrees - basically, if it's vaguely recent and has a USB charging port, it's almost certainly lithium cells inside... About a quarter of the world's production goes into BEV and HEV vehicles - and that isn't just cars, it's ebikes and all the toot like hoverboards. What proportion catch fire charging? Absolutely minimal [...] Not that rare, unfortunately, see eg www.london-fire.gov.uk/safety/lithium-batteries/charging-electric-bike-and-electric-scooter-lithium-batteries/Chances are most of the fires are with cheap and/or illegal kit bought off the internet, but even reputable brands can fail. My last phone developed a swollen battery, which I only realised when its protective case split. It had always got rather warm when using the fast charger supplied with the phone. These days I use a slower charger unless I really need the speed, which is rare, and if I do need a fast charge I take my phone out of the case to minimise overheating. Oddly had a similar experience recently with an MP3 player, I was sitting in my lounge and I heard a loud crack then a series of much shorter but distinct cracks like glass breaking, on investigation I found the MP3 player had a broken and loose screen and as I held it there was another crack and the screen came even looser, I can see the battery is swollen and has obviously pushed the screen out.
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adrianc
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Post by adrianc on Aug 26, 2023 9:21:44 GMT
Swollen batteries aren't unique to lithium - they've been doing it since at least the days of NiMH.
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