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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

#131

Post by OneDeuxTriSeiGo »

hinkley wrote: post #110
CyberDildonics wrote: post #100

Earlier quoted context omitted.

You are talking about cells going bad and they are talking about cells that have less capacity from being cycled, not the same thing at all.

No I’m talking about what warrants putting a pack on the secondary market and they’re being unreasonable. Just being 80% of initial capacity isn’t going to prompt someone to swap the batteries out. A damaged pack will.

Ehhh it really depends. There are plenty of vehicles that are getting traded in where manufacturers/dealers would rather just replace the batteries.

I'd wager the bulk of them are hybrids where the batteries see a pretty aggressive charge/discharge cycle on a relatively small capacity (and therefore being relatively cheap to replace compared to a full electric). Of course then there are also full electrics where the owners get upgraded capacity or replacements due to degradation from use.

And importantly they aren't just recycling EV batteries here. They are using lithium-ion, nickel metal-hydride, and lead-acid batteries. So they are also buying up traditional ICE automotive batteries as well.

Also worth noting this project is a collaboration between Toyota, JERA, and local universities for use at JERA's facilities. JERA is a large battery reprocessing and recycling company so they are already getting second hand batteries into their facilities on a regular basis. This project is primarily about doing the design and engineering work necessary so that JERA can set up an array of these battery containers, get notified when a unit fails, and swap out the battery with one from their stock for recycling.

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

#132

Post by rsynnott »

hinkley wrote: post #109
fooker wrote: post #105

Earlier quoted context omitted.

A great range extender weighing twenty kilos is available right now, a diesel generator. It can also double as a air/water heater, emergency power for household or medical appliances, and emits about as much carbon in 30 years as it takes to manufacture a battery pack.

Honestly surprised Honda hasn’t designed a hybrid that’s more generator and less hybrid but I suspect that has to do with air and noise pollution loopholes for generators versus engines.

Nah, the BMW i3 had one of these as an option, as does some Chinese car, with no regulatory difficulties. Also a common arrangement for ‘hybrid’ buses and trains.

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

#133

Post by rini17 »

DanielHB wrote: post #121
pornel wrote: post #28

Those who TL;DRd - it's for the factory, not the cars! Old EV batteries are great for energy storage. A worse weight-to-capacity ratio doesn't matter for batteries sitting on the ground. A battery that holds only 70% of its original capacity is considered worn-out for EVs (and even replaced under warranty), but grid storage isn't driving anywhere, so any capacity left is still useful.

Balancing multiple battery packs at different wear levels is a huge nightmare. You have to run rebalancing operations all the time and on used packs it can be quite dangerous to trigger a thermal runaway. If they do it with different types of batteries it is even more complicated, like you need to write some custom software to sync all that up. This is not a trivial project.

They reuse inverters too. So the packs are separated, no need to balance.

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

#134

Post by [deleted] »

rini17 wrote: post #133
DanielHB wrote: post #121

Earlier quoted context omitted.

Balancing multiple battery packs at different wear levels is a huge nightmare. You have to run rebalancing operations all the time and on used packs it can be quite dangerous to trigger a thermal runaway. If they do it with different types of batteries it is even more complicated, like you need to write some custom software to sync all that up. This is not a trivial project.

They reuse inverters too. So the packs are separated, no need to balance.

[deleted]

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

#135

Post by OneDeuxTriSeiGo »

lillecarl wrote: post #92
hinkley wrote: post #49

Earlier quoted context omitted.

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.

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…

> precautionary principle when we run nuclear, build dams

Yes. Dams in particular. You calculate for various failure modes and you design around mitigating the disaster if failure should occur. That's why dams are designed with emergency spillways. If there is a bunch of rain, gate failures, etc and you suddenly have more water than you know what to do with, you have the emergency spillway as a last resort. They exist to route water in high volume out of the resevoir, often in a sacrificial manner in an attempt to prevent the dam from failing. And if a dam would fail, it's preferably that it do so at the emergency spillway than elsewhere. So there is a certain amount of "in certain conditions failure can/will happen so this is how we design the system to fail as gracefully/least destructively as possible".

Nuclear has this as well. The plans for this are called "Severe Accident Mitigation Guidelines" or SAMGs with the general practice being called SAM (same abbreviation, just drop the G). Each nuclear site has them and they are generally framed as "this shouldn't go wrong but if it does". You can try to avoid those failure modes but they can always still potentially occur and the most you can do is just try to keep the damage from spreading to the best of your ability.

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

#136

Post by mNovak »

numpad0 wrote: post #107

Looks like this is a PoC for Toyota's "sweep storage system" using "low voltage MOS", which seem to be a fancy invented term for a charge/discharge current limiter. [2] has photos of previous PoC from 2023. 1: https://global.toyota/jp/newsroom/corporate/43207750.html 2: https://www.power-academy.jp/sp/electronics/report/rep03200....

I think the "low voltage MOS switch" is just a roundabout way of saying MOSFET, which is very common in power electronics generally.

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

#137

Post by margalabargala »

londons_explore wrote: post #126
margalabargala wrote: post #99

Earlier quoted context omitted.

Why can you not bypass until the voltage falls to zero? I'm with you aside from that.

If you just close the bypass switch, a large current will flow out of the (dying) cell, making a lot of heat. You could have a two-way bypass, disconnecting the original cell, but that would cost more. Remember the bypass switch is duplicated for every series cell group (hundreds) and must carry the whole battery current. Or you could have some kind of slow drain resistor - but then you're back to the time issue.

Okay, I understand. I was definitely imagining some sort of latching switch, that would connect to the bypass instead of the cell. Makes sense that would be more expensive.

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

#138

Post by willlma »

This is not recycling. Recycling implies that you can produce the same product again many times; it's a sustainable practice. This is repurposing or upcycling. It's cool they're getting a second life, but they won't get a 3rd, 4th, Nth life unless the batteries are actually recycled into their component materials at end-of-life. It's kind of like the plastic brick companies: cool that plastic is being turned into a construction material, but it doesn't mean we can stop mining for the primary source material any time soon.

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

#139

Post by noboostforyou »

hinkley wrote: post #47
pornel wrote: post #28

Those who TL;DRd - it's for the factory, not the cars! Old EV batteries are great for energy storage. A worse weight-to-capacity ratio doesn't matter for batteries sitting on the ground. A battery that holds only 70% of its original capacity is considered worn-out for EVs (and even replaced under warranty), but grid storage isn't driving anywhere, so any capacity left is still useful.

Battery banks are worse than degraded raid arrays in some important respects. The bad cells tend to try to bring the rest of the pack with them. It’s one of the reasons people keep toying with partitioning cells and putting controllers onto individual cells or small groups of them. Parting out two or three dead battery packs to cull the best of the survivors can improve things quite a bit. And as you say, on a statio…

> It’s one of the reasons people keep toying with partitioning cells and putting controllers onto individual cells or small groups of them.

I have been out of the battery tech game for a while now but decades ago we were balancing individual NiCd and NiMH cells for optimal performance, is this basically the same thing?

https://electronics.stackexchange.com/questions/463591/nicke...

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

#140

Post by foxyv »

noboostforyou wrote: post #139
hinkley wrote: post #47

Earlier quoted context omitted.

Battery banks are worse than degraded raid arrays in some important respects. The bad cells tend to try to bring the rest of the pack with them. It’s one of the reasons people keep toying with partitioning cells and putting controllers onto individual cells or small groups of them. Parting out two or three dead battery packs to cull the best of the survivors can improve things quite a bit. And as you say, on a statio…

> It’s one of the reasons people keep toying with partitioning cells and putting controllers onto individual cells or small groups of them. I have been out of the battery tech game for a while now but decades ago we were balancing individual NiCd and NiMH cells for optimal performance, is this basically the same thing? https://electronics.stackexchange.com/questions/463591/nicke...

Usually a group of cells are welded together using a conductor. If they are in series, you need to balance the cells using balance leads. If they are in parallel though, they are balanced ahead of time to prevent too much current between the cells and thereafter they will balance themselves once they are wired in parallel.

In a parallel bank, a single cell going bad can bring down the rest to the same voltage. Even worse, if the bank is directly connected to other banks it can take out them as well. Also, if there is an internal short in one battery, the rest will pump current through it very effectively lighting it on fire. Individual battery protection circuits, smart switches, and internal short detection can help with this.

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