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Toyota is recycling old EV batteries to help power Mazda's production line

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Re: Toyota is recycling old EV batteries to help power Mazda's production line

#111

Post by jama211 »

lillecarl wrote: post #43
jama211 wrote: post #36

Earlier quoted context omitted.

There’s quite a lot you can do when you can isolate and deactivate individual cells, big battery packs like this really do not fall off a cliff in the same way you’re describing.

How do you achieve this with cells in series? Do you kill an entire row and put it on "maintenance voltage"? I know how balance charging RC batteries work but they're smaller scale and "single row". Also in RC car world it's generally preferred to have one cell per voltage step, I've had way more dual-cell(per series) packs fail than single ones. Though my experience is only 6s/~22v but it's "the same shit on a bigge…

I don’t know to be honest, I just know that you can find second hand car batteries that have been used for 15/20 years that still have 40% charge and I don’t know of any single phone battery that’d be the same. I could be talking out of my ass but that’s what I thought.

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#112

Post by jama211 »

robin_reala wrote: post #38
jama211 wrote: post #35

Earlier quoted context omitted.

I saw that 787B at the Adelaide motorsport festival, MAN that thing makes an incredible noise!!!

Also an iconic paint job. Mazda UK did a special edition MX-5 with a turbo and that paint to celebrate the Le Mans win: https://www.pistonheads.com/news/ph-features-heroes/ph-heroe...

That’s so cool

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#113

Post by namibj »

lillecarl wrote: post #89
londons_explore wrote: post #62

Earlier quoted context omitted.

Nearly all EV's today would run just fine on 3.7 volts fewer. My car's high voltage circuitry seems to work down to about half of the nominal voltage.

Is the failure mode of whatever chemistry is in an EV that they just conduct electricity? Li-Po usually fail in more spectacular ways than so.

There's NCA (drones), NMC (laptops, phones, many electric cars), LFP (stationary/grid), and LFMP (many new electric cars; slightly more expensive but higher current variant of LFP).

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#114

Post by myrmidon »

arghwhat wrote: post #90
lotharcable wrote: post #82

Earlier quoted context omitted.

Generally speaking the cells that are welded on are designed to be welded on in the areas were you do the welding. Doing something other then welding on them properly is going to be more unsafe then welding. The proper tools to do this are not that expensive anymore in the greater scheme of things. It is just a question of whether or not it is worth to do it at the scale you are doing it or pay somebody else to do it…

> Generally speaking the cells that are welded on are designed to be welded on in the areas were you do the welding. ... by automated spot welder programmed to the specified timing and temperature control from the cell spec sheet, in a controlled environment with suitable protection and fire suppression for a battery manufacturing line. Not by a hobbyist's first try with a homemade spot welder and a safety squint. I…

Seconding that advice to just use prismatic lifepo cells. Those have become really cheap, too: You can order brandnew 1kWh cells for $60ish + shipping even if you only need single digit quantities (those want to be squished a bit for longevity, so you might have to design a suitable enclosure).

Energy autarky has never been so affordable, progress on batteries and solar panels was awesome over the last decade.

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#115

Post by eru »

Cthulhu_ wrote: post #66
londons_explore wrote: post #41

Earlier quoted context omitted.

If you take car EV batteries and use them for stationary storage when past end-of-life, the fire risk becomes fairly substantial because EV batteries often have a little water ingress, physical damage etc. It can be solved by isolating each battery in its own steel box, but that gets fairly expensive fairly fast.

I've seen a video on the youtube where a battery recycling company does this; they leave the car battery packs in their original housing, which I presume is water resistant enough. Each unit is also connected to a controller, which I also presume monitors battery health, temperature (assuming temp sensors on car battery packs), voltage, etc. If a unit is dying they can safely dispose of it, else, the units were out i…

> Very space inefficient though, but there's more than enough of that in the US.

Well, you could perhaps put photovoltaic cells on top to use that space? Your battery park needs to be connected to the grid anyway.

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#116

Post by eru »

hinkley wrote: post #49
lillecarl wrote: post #46

Earlier quoted context omitted.

How much distance does one pack realistically need to not cascade? Honestly I can't imagine any more than half a meter since air is an extremely good insulator. Just make sure the fire can't crawl across though cable insulation? I've personally set RC lipo on fire with the wood-nail-hammer technique and while the fire out of the pack is intense I can't imagine it igniting another pack.

Precautionary principle. There’s not good ways to extinguish these fires once they start. So you kinda have to let them go. Maybe you could use some sort of deluge system or aggressive liquid cooling on the surrounding cells however. Overbuilding the delivery system but then running the pumps at their most efficient cfm except when the smoke alarms go off.

> There’s not good ways to extinguish these fires once they start.

If one battery pack catches fire, you can start moving the others away from it.

If you normally keep 0.5m between them, you have plenty of buffer space to eat into.

Basically it would start as . . . X . . . with X being the pack on fire "." being a battery pack not on fire, and " " being the half metre between them. Then you move them to get:

... X ...

Where the dots now have perhaps only 30cm between them, but the space to the X is increased.

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#117

Post by [deleted] »

hinkley wrote: post #49
lillecarl wrote: post #46

Earlier quoted context omitted.

How much distance does one pack realistically need to not cascade? Honestly I can't imagine any more than half a meter since air is an extremely good insulator. Just make sure the fire can't crawl across though cable insulation? I've personally set RC lipo on fire with the wood-nail-hammer technique and while the fire out of the pack is intense I can't imagine it igniting another pack.

Precautionary principle. There’s not good ways to extinguish these fires once they start. So you kinda have to let them go. Maybe you could use some sort of deluge system or aggressive liquid cooling on the surrounding cells however. Overbuilding the delivery system but then running the pumps at their most efficient cfm except when the smoke alarms go off.

[deleted]

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#118

Post by lillecarl »

tyrshand wrote: post #98
lillecarl wrote: post #92

Earlier quoted context omitted.

Do we use the precautionary principle when we run nuclear, build dams and burn coal as well or is this an extra thing because it's a potentially good way to reuse EV batteries? I don't think we should build these hand-me-down EV batteries near population centers, but my understanding is that the worst case scenario would be the plant burning down and releasing bad things (hello coal & natgas) into the atmosphere? If…

"Do we use the precautionary principle when we run nuclear, build dams and burn coal as well" ayfkm?

Dams bust, nuclear blows up. It's rare but it happens. Their worst case scenarios are worse than a park of batteries burning down on a gravel/concrete park?

Your interpretation seems to be "we don't use caution when building them" which is not what I meant at all, we do but the risk is non-zero.

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#119

Post by lillecarl »

crote wrote: post #108
lillecarl wrote: post #46

Earlier quoted context omitted.

How much distance does one pack realistically need to not cascade? Honestly I can't imagine any more than half a meter since air is an extremely good insulator. Just make sure the fire can't crawl across though cable insulation? I've personally set RC lipo on fire with the wood-nail-hammer technique and while the fire out of the pack is intense I can't imagine it igniting another pack.

Don't forget about radiant heat! There's a pretty much perfect insulator between the sun and Earth conduction-wise, yet it is still pretty cozy up here.

That's fair, I don't know how to calculate this but my naive assumption is a burning pack won't radiate enough to combust something 1 meter away if there's circulating air around.

Re: Toyota is recycling old EV batteries to help power Mazda's production line

#120

Post by appointment »

zhyder wrote: post #88
TGower wrote: post #85

Earlier quoted context omitted.

A few tradeoffs you might not be considering: EV battery packs operate at voltages that are seriously hazardous. Consumers coming anywhere near those plugs is a non-starter, so even more bulk, weight, and complexity would need to be added to make the installation process foolproof. Waterproofing is critical, the mechanism has to work flawlessly over insertion/removal cycles to keep a watertight seal.

Great points. Re safety, I wasn't imagining the consumer doing it themselves but some robot like ones imagined for whole-battery swapping (e.g. https://youtu.be/Oj6LaYFall4 ); I think any battery swapping only makes sense for batteries you rent rather than own.

What does "imagined" mean? Nio has been doing automatic battery swaps on a mass scale for years.
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