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Electric cars, some science on the battery packs


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#1 eruptn

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Posted 09 April 2018 - 02:28 PM

Hi

 

It appears the 2nd Generation battery packs in the Nissan Leaf have a major issue.

 

https://www.preprint.../201803.0122/v1

 

 


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#2 Island Time

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Posted 09 April 2018 - 03:18 PM

Interesting. Thanks for the post..


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There is nothing, absolutely nothing, half so much worth doing, as simply messing about in boats


#3 Knot Me... maybe

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Posted 09 April 2018 - 07:30 PM

Car batteries use button cell's because they are cheap to make from lower grade materials.

 

I've got prismatic cells. Far flasher and better but also far more expensive.


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#4 wheels

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Posted 10 April 2018 - 06:29 AM

ummm.......nooo....not as far as I know, button cells are not used in Cars. They are not usually rechargable. Unless I have a different understanding to button cell than you do.
There are Prismatic and Pouch. Both are very similar looking and a non expert would not be able to tell which is which. The Pris was developed early 90's and the Pouch about mid 90's. Prismatic is what is the common Cellph and laptop Battery is these days. Although larger units are also used in Vehicle batteries. Pouch is the more modern and most common in Vehicle batteries these days, because it is the lightest. The Prismatic requires a welded metal case around it to keep the cell from damage due to gas build up. The Pouch also swells, but it can withstand it and the difference is that they allow for the expansion within the case.


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#5 Knot Me... maybe

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Posted 10 April 2018 - 08:05 AM

 Unless I have a different understanding to button cell than you do.

I would think so reading that.

 

I got to suss deep into some bigger serious Lithium batteries and in chatting about costs coming down it was mentioned unlikely as the cells used in serious gear are tightly controlled prismatic so big cost reductions are unlikely. But the cheaper batteries like used in cars, and I'm sure the term 'button cell' was what they were using, are made more to a price and easily so the prices should continue to decrease over time.

 

In them are lots of little wires, circuit boards and some rectangular thingys, the cells themselves.

 

It was very interesting. Especially so when it went a wee way to explain why saying 'lithium battery' is the same as saying 'boat'. There are many sorts made differently from differing materials for assorted applications.


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#6 dutyfree

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Posted 10 April 2018 - 08:05 AM

A friend has a Leaf, factored in cost to replace battery etc when he bought it (very smart guy, electrical engineer background), but recently told me his battery is degrading faster than he expected (I think as he is driving it every day, so cycling more then he thought).  He told me that he cant find anyone in NZ to replace it yet and that he cant get the battery for his model so my have to get a replica from overseas.


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#7 Knot Me... maybe

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Posted 10 April 2018 - 08:17 AM

A friend has a Leaf, factored in cost to replace battery etc when he bought it (very smart guy, electrical engineer background), but recently told me his battery is degrading faster than he expected (I think as he is driving it every day, so cycling more then he thought).  He told me that he cant find anyone in NZ to replace it yet and that he cant get the battery for his model so my have to get a replica from overseas.

There's been a huge issue with those batteries. It's been known for a while but has just hit the headlines.

There will be many more to come as the more we have to rely on black boxes full of hocus pocus the more the things like this will increase. As will our costs in trying to keep them working.

 

The best place for a leaf is on a branch..... or if you are 15 the ones inside a Playboy ;)


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#8 erice

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Posted 10 April 2018 - 11:10 AM

afaik

 

some years ago honda hybrid batteries were also struggling to meet their design life...

 

they were hybrids so just spent more time using their puny motors but for an all electric car like the leaf battery life is king

 

esp. in cold winters with the heater running, the wipers working and headlights on for both commutes


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ACT NOW!

 

don't wait for everyone else

 

to save you from yourself


#9 wheels

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Posted 10 April 2018 - 06:41 PM

I said this here a long time back. One of the big killers to EV take up, will be resale value. EV's are expensive to start with. But if it is known that the batteries are not going to last long (and they can be real expensive to replace) then no one is going to want to buy them and thus the trade in price will be low. So it becomes a double whammy cost wise. That would then make people rather shy of buying another and those contemplating buying their first rather nervous of doing so.

There are new advances in Battery technology sitting on the near horizon. But they are still revolving around Lithium. The advancements address the charge discharge times and the Current available. This does not address that fact that we are relying on a two way chemical reaction and thus there is a small loss every time a charge and discharge occurs. There is no getting around that. So the battery eventually dies. Everyone looks at how many charge cycles a Battery can take, but very few if any ever talk about the loss of performance over those cycles. For a House of Boat, that is not quire such and issue, because you just charge up more often as it gets older. But for a vehicle, it is a case of not getting as far each time it cycles. Eventually the Vehicle becomes useless as you would need to charge far too often to get anywhere.
 


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#10 Knot Me... maybe

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Posted 11 April 2018 - 01:57 PM

Agree, the key to anything electric be it car or boat or many other things is storage. Unless you have lots of that easily and at a reasonable price there will be struggles.

 

From what I've been learning and seeing the technology is there or very damn close but it's not going to come cheap. It seems to be green you need to a sh*t load of coin or to be born a frog.


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