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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

#21

Post by lstodd »

bri3d wrote: post #11
zhyder wrote: post #4

Neat idea to mix batteries of different age and chemistries. I've wondered why EVs couldn't do that too with some power electronics and SW. If an EV battery could have multiple such modules, it'd: 1) Make it easier to carry a cheaper lighter less-natural-resources-consuming battery most of the time. Go to some "gas station" to rent and add more modules when taking a road trip 2) Make it cheaper to replace the 1 modul…

It's quite likely that lower discharge rate requirements are a large part of what makes this system function. Batteries with different internal resistance can work reasonably well even in a naive series system at low discharge rates but absolutely will not work at high discharge rates.

exactly.

state-of-charge / depth-of-discharge vs lifetime accumulated "discharge stress" so to say also matters a lot.

batteries aren't simple, even lifepo4 ones.

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

#22

Post by stetrain »

zhyder wrote: post #4

Neat idea to mix batteries of different age and chemistries. I've wondered why EVs couldn't do that too with some power electronics and SW. If an EV battery could have multiple such modules, it'd: 1) Make it easier to carry a cheaper lighter less-natural-resources-consuming battery most of the time. Go to some "gas station" to rent and add more modules when taking a road trip 2) Make it cheaper to replace the 1 modul…

GM claims that this is exactly how their Ultium battery pack architecture works. It is made up of multiple modules each with their own BMS, and supposedly one module can be replaced without having to be a match in chemistry and degradation to the other modules.

I'm unsure if that will actually work so well in practice, where you still need to charge all the cells simultaneously when doing DC fast charging etc.

Also all of that extra architecture adds cost and complexity to each vehicle that rolls out the door, compared to a pack that just packs in a bunch of cells together with the necessary cooling etc. as one contiguous unit.

Given that EV battery packs in the real world are trending to last longer than the cars they come in, going with a simpler pack design and swapping in a refurbished pack if you experience a premature failure might be the more economical route.

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

#23

Post by kenhwang »

redwall_hp wrote: post #16
bluGill wrote: post #2

had to check: toyota owns 5% of mazda which makes them the largest shareholder.

Toyota also owns Daihatsu, which is a lesser known name in the US, but is a major maker of kei cars, which are huge in Japan and other parts of Asia. They also own Denso, which is the second largest auto parts company. And they partner with Subaru on some things, such as the Subaru BRZ and Toyota GR86, which are basically the same car with different badging.

Toyota owns a de facto controlling stake in Subaru (~20%).

Due to typical Japanese corporation by-laws, it only takes 33% share ownership for uncontested control of a corporation, and >50% of 33% means they'll never lose a vote for simple majority matters, which is basically everything except selling or dissolving the company.

The 20% threshold is for a guaranteed seat on the board, which lets them put issues up for a vote.

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

#24

Post by rubyn00bie »

zhyder wrote: post #4

Neat idea to mix batteries of different age and chemistries. I've wondered why EVs couldn't do that too with some power electronics and SW. If an EV battery could have multiple such modules, it'd: 1) Make it easier to carry a cheaper lighter less-natural-resources-consuming battery most of the time. Go to some "gas station" to rent and add more modules when taking a road trip 2) Make it cheaper to replace the 1 modul…

I hadn’t thought about different sizes/weights but this does remind me of Nio’s battery swap network. Which I’ve always been fond of in principle. I think at some point in the future, when range isn’t such a competitive advantage in the EV space we’ll see a push towards standardization and something like this will likely occur. I’d guess something around the 1000 mile mark for an EV. Absurd, yes, but at that point no one will complain about range and that sort of implied density/efficiency also allows for a better towing experience (at least here in the states). If someone can get a 1000 miles of range, but only drives 100 miles at a time TCO drops immensely because tires/brakes last much longer at lower weights.

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

#26

Post by lstodd »

smileysteve wrote: post #14
zhyder wrote: post #4

Neat idea to mix batteries of different age and chemistries. I've wondered why EVs couldn't do that too with some power electronics and SW. If an EV battery could have multiple such modules, it'd: 1) Make it easier to carry a cheaper lighter less-natural-resources-consuming battery most of the time. Go to some "gas station" to rent and add more modules when taking a road trip 2) Make it cheaper to replace the 1 modul…

Re: 1, ignoring the complexities, is really interesting but depending on the effort to change our battery banks quickly makes renting a car more feasible. And this highlights American traffic and sparseness. - plug-in hybrids have 10-13 mile range which is great for running a few errands (this is only slightly more feasible than in a golf cart or ebikes) - also great for last mile connectivity for mass transit n user…

actually if you can get a late-1990-ish 90-100cc 2T japanese scooter like Honda Lead 90 or Suzuki Address 100, or even later Yamaha Neos / MBK Ovetto 100cc of 2005-ish vintage this whole discussion about ranges and fuel consumptions becomes pointless.

because those have had fuel consumption of like 2-3L per 100km. with fuel tanks of about 6L you had all the range for errands you could possibly need.

and they were capable of moving two persons around _and_ moving a ton of grocery, or something like an ironing board.

hell, in 2000s we were doing 700km trips on them.

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

#27

Post by toast0 »

smileysteve wrote: post #14
zhyder wrote: post #4

Neat idea to mix batteries of different age and chemistries. I've wondered why EVs couldn't do that too with some power electronics and SW. If an EV battery could have multiple such modules, it'd: 1) Make it easier to carry a cheaper lighter less-natural-resources-consuming battery most of the time. Go to some "gas station" to rent and add more modules when taking a road trip 2) Make it cheaper to replace the 1 modul…

Re: 1, ignoring the complexities, is really interesting but depending on the effort to change our battery banks quickly makes renting a car more feasible. And this highlights American traffic and sparseness. - plug-in hybrids have 10-13 mile range which is great for running a few errands (this is only slightly more feasible than in a golf cart or ebikes) - also great for last mile connectivity for mass transit n user…

PHEVs were quoting 20+ miles on electric last decade, I think 25-35 is common now?

Actual distance depends on elevation changes and speed/driving, but 15-20 is quite acheivable, as long as you don't make it to highway speeds. And if you go a bit farther and use a splash of gas, no big deal, that's why it has a tank.

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

#28

Post by pornel »

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.

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

#29

Post by whatever1 »

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.

At the cell level they don’t degrade linearly. First it’s slow then it’s fast and then it’s abrupt collapse. You probably have noticed that yourself with old devices. Some do not hold charge even for a minute.

With battery packs probably you can do some smart things to make the degradation curve look more linear, but again there is only so much you can do.

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

#30

Post by stetrain »

lstodd wrote: post #26
smileysteve wrote: post #14

Earlier quoted context omitted.

Re: 1, ignoring the complexities, is really interesting but depending on the effort to change our battery banks quickly makes renting a car more feasible. And this highlights American traffic and sparseness. - plug-in hybrids have 10-13 mile range which is great for running a few errands (this is only slightly more feasible than in a golf cart or ebikes) - also great for last mile connectivity for mass transit n user…

actually if you can get a late-1990-ish 90-100cc 2T japanese scooter like Honda Lead 90 or Suzuki Address 100, or even later Yamaha Neos / MBK Ovetto 100cc of 2005-ish vintage this whole discussion about ranges and fuel consumptions becomes pointless. because those have had fuel consumption of like 2-3L per 100km. with fuel tanks of about 6L you had all the range for errands you could possibly need. and they were cap…

Small 2-stroke engines tend to be worse for pollution emissions (NOx, particulates) despite generally good fuel efficiency.
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