The problem is likely cost effectiveness compared to just replacing a whole group of cells, compared to one single cell.
The unit economics of getting the remaining life from single used laptop battery are not very good. There's certainly lots of potential value for someone willing to do the work, if they can afford the opportunity cost, or if a business can source extremely dirt cheap cells and cheap high skilled labor.
You would be amazed how many battery packs are multiple 18650s in a trenchcoat. Even EV battery packs use them. Though it does raise the question - wouldn't an old EV battery be a better solution than stripping apart laptops?
There's a lot that goes into manufacturing battery packs beyond the cells. How's your thermal path to ambient in your home wall battery? How is the inter-cell thermal isolation? Is there a path for gas discharge in the event of a cell failure? Is the pack appropriately fused at the cell or module level? When a cell fails, does it take the whole pack with it, catch someone's apartment building on fire and kill a family of 5, or merely become stinky with a hotspot visible on IR?
How good is your cell acceptance testing? Do you do X-ray inspection for defects, do ESR vs cycle and potentially destructive testing on a sample of each lot? When a module fails health checks in the field, will you know which customers to proactively contact, and which vendor to reassess?
Yeah lots of batteries are 18650/26650 in a trenchcoat. The trenchcoats run the gamut from "good, fine" to "you will die of smoke inhalation and have a closed casket" in quality and I think that bears mentioning.
I get that the trenchcoat needs to be well designed and tested, but I am still flat out amazed that you both agree with “meh, most battery packs are made up of rechargeable domestic batteries you find in a kids toy”
Probably, but EV batteries are large enough that there might be an industrial recycling process for them, while old laptop batteries are basically free because it's too much labor to extract useful value from them.
I'm pretty sure most industrial recycling methods for lithium batteries involve grinding them up, so pack size isn't as much a factor as sheer volume. I think there just wasn't much juice for the squeeze until demand from EVs made recycling worthwhile.
> You would be amazed how many battery packs are multiple 18650s in a trenchcoat
Also laptop batteries used to be many (usually three or six) 18650s in a plastic trenchcoat.
You could literally rebuild your battery when it died, and pick the cells you liked the most. In theory you could pick higher-quality cells than those you find in the batteries sold on ebay from chinese stores. In theory.
When battery packs that have a non-zero chance of literally killing your users are commonplace, it actually does make sense to vendor-lock the battery. Believe it or not there is actual engineering that goes into making batteries beyond spot welding them to an interconnect and stuffing them into $.50 of ABS enclosure.
That depends on the problem you're trying to solve. If it's only to build a home power system, sure, but if the goal is "I want to prevent these laptop batteries from ending up in a landfill" then using an old EV battery doesn't really help you much.
FWIW a lot of EVs use prismatic cells, not cylinder cells. Tesla, Rivian, and Lucid use cylindrical cells. Hyundai, Volkswagen, BMW, GM, Ford, and BYD all use prismatic cells.
Currently, that is LiFePO4. It is cheaper than LiPo packs used in electronics, half the energy density, twice as many charge cycles, and doesn't burst into flame. The lithium is flammable but requires external ignition.
Larger batteries, including some electric cars, have switched.
It seems unlikely that there's any practical chemical batteries with 0 fire risk.
But I do think there should be home energy storage that doesn't involve chemical batteries. Where are all the pumped hydro, flywheels, and compressed air storage for consumer use?
There's already a pipeline sending old electronics to cheap labor for possible refurbishing, recycling and/or incorrect disposal. A small percentage they repackage into replacement laptop batteries and ship back, but they could also send more of them back as a value UPS with different value add parts.
Personally, I expect there to be a massive conversion to USB-PD as the primary power in the cellphone only regions.
Building large battery arrays out of old recycled cells does not require bringing the workers to the battery cells, any more than building iPhones requires you to bring the workers to where they mine ore. Large-scale product development often involves shipping materials and half-finished products around the world multiple times.
You would never do this in a production product. You need batteries with similar internal impedances or undesirable things happen. This is the battery equivalent of the guy who welds two car front ends together and drives it around. It's cool and quirky but not a useful product for most people.
From what I've heard, it is more economical to recycle the raw materials than to reuse small packs.
Reuse of vehicle sized packs seems to be pretty common, though. I'd guess that a DIY home backup could be built pretty easily from used vehicle batteries.
The dude has a warehouse/workshop to do this work and house the system. I’m super impressed by what he’s accomplished, don’t get me wrong; but, what he’s done just isn’t viable for 99.99999999999% of people.
Give me an array and battery system that can pull off the grid and/or array and power most of my home without me having to think a whole lot or pay a vendor thousands to install while making the total cost under $1000 and I’ll do it.
Until then, it just isn’t financially viable when my electricity costs are well under $70/month average across the year.
Recouping the costs for install of solar systems are estimated at 30-40 years as of 4 years ago when I researched it. I’m sorry, but that’s just not worth it for me and most others.
Sure, but it does get a lot simpler if you start from modules instead of cells. Nothing will get around the requirement to have electrical knowledge.
Cost is always an issue. These rarely make sense from a pure $$ sense, as everything in electrical is expensive. You could burn up that $1000 budget just to get a subpanel installed.
Usually the value proposition is some combination of savings, combined with the ability to backup critical loads. A generator could do that too, but a proper generator setup isn't cheap either, and it wouldn't save $$ at all. Battery solutions sometimes beat that.
Buying a used Nissan Leaf and using V2H feature in CHAdeMO is it. Or you can remove and use its well-reverse-engineered minimum nominal 24kWh semi-removable battery. But no one wants a Leaf, so there's that.
Isn't the problem with parasitic charging? Suppose you had a bunch of used 18650 cells. To scale the electronics, they'll be wired up in parallel and/or series so the charging logic can be shared, but since the batteries are wildly mismatched, it results in parasitic charging.
(This might already be happening, but I haven't heard about it) The big thing EVs need right now is standardized battery packs. It reduces replacement cost, takes away anxiety that a replacement will exist when you need it, and enables down-cycle uses like stationary storage.
The problem is likely cost effectiveness compared to just replacing a whole group of cells, compared to one single cell. The unit economics of getting the remaining life from single used laptop battery are not very good. There's certainly lots of potential value for someone willing to do the work, if they can afford the opportunity cost, or if a business can source extremely dirt cheap cells and cheap high skilled labor.
You would be amazed how many battery packs are multiple 18650s in a trenchcoat. Even EV battery packs use them. Though it does raise the question - wouldn't an old EV battery be a better solution than stripping apart laptops?
There's a lot that goes into manufacturing battery packs beyond the cells. How's your thermal path to ambient in your home wall battery? How is the inter-cell thermal isolation? Is there a path for gas discharge in the event of a cell failure? Is the pack appropriately fused at the cell or module level? When a cell fails, does it take the whole pack with it, catch someone's apartment building on fire and kill a family of 5, or merely become stinky with a hotspot visible on IR?
How good is your cell acceptance testing? Do you do X-ray inspection for defects, do ESR vs cycle and potentially destructive testing on a sample of each lot? When a module fails health checks in the field, will you know which customers to proactively contact, and which vendor to reassess?
Yeah lots of batteries are 18650/26650 in a trenchcoat. The trenchcoats run the gamut from "good, fine" to "you will die of smoke inhalation and have a closed casket" in quality and I think that bears mentioning.
Where would you put this battery in that trenchcoat gamut? Inside a server rack, fwiw. https://signaturesolar.com/eg4-lifepower4-v2-lithium-battery...
Was definitely one of the harder parts of our solar install to get comfortable with.
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I get that the trenchcoat needs to be well designed and tested, but I am still flat out amazed that you both agree with “meh, most battery packs are made up of rechargeable domestic batteries you find in a kids toy”
I just assumed there was … special stuff in there
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Probably, but EV batteries are large enough that there might be an industrial recycling process for them, while old laptop batteries are basically free because it's too much labor to extract useful value from them.
I'm pretty sure most industrial recycling methods for lithium batteries involve grinding them up, so pack size isn't as much a factor as sheer volume. I think there just wasn't much juice for the squeeze until demand from EVs made recycling worthwhile.
Here's a video inside a recycling plant: https://www.youtube.com/watch?v=s2xrarUWVRQ
> You would be amazed how many battery packs are multiple 18650s in a trenchcoat
Also laptop batteries used to be many (usually three or six) 18650s in a plastic trenchcoat.
You could literally rebuild your battery when it died, and pick the cells you liked the most. In theory you could pick higher-quality cells than those you find in the batteries sold on ebay from chinese stores. In theory.
>You would be amazed how many battery packs are multiple 18650s in a trenchcoat
$50 of 18650s in a $500 trenchcoat with DRM protection. So wasteful.
When battery packs that have a non-zero chance of literally killing your users are commonplace, it actually does make sense to vendor-lock the battery. Believe it or not there is actual engineering that goes into making batteries beyond spot welding them to an interconnect and stuffing them into $.50 of ABS enclosure.
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"Cheaply made, not cheap to buy!"
That depends on the problem you're trying to solve. If it's only to build a home power system, sure, but if the goal is "I want to prevent these laptop batteries from ending up in a landfill" then using an old EV battery doesn't really help you much.
FWIW a lot of EVs use prismatic cells, not cylinder cells. Tesla, Rivian, and Lucid use cylindrical cells. Hyundai, Volkswagen, BMW, GM, Ford, and BYD all use prismatic cells.
There is a lot of liability in sticking your name on a hodge podge of random used lithium cells.
I feel like for home battery backup there needs to be some kind of lower energy density solution that has zero fire risk.
Weight is not a factor for home energy storage, there is no need for lithium cells.
Currently, that is LiFePO4. It is cheaper than LiPo packs used in electronics, half the energy density, twice as many charge cycles, and doesn't burst into flame. The lithium is flammable but requires external ignition.
Larger batteries, including some electric cars, have switched.
LiFePO₄ (LFP) is overwhelmingly safe and cheap. Lithium isn't the problem here exactly.
It seems unlikely that there's any practical chemical batteries with 0 fire risk.
But I do think there should be home energy storage that doesn't involve chemical batteries. Where are all the pumped hydro, flywheels, and compressed air storage for consumer use?
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LFP is the present solution, but sodium ion is the next step. Given the abundance of sodium in the sea there should never be any problem sourcing it.
https://cambridgerenewables.co.uk/product/eleven-energy-4-5-...
Weight is not a factor for home energy storage, there is no need for lithium cells.
That depends on your living situation. I live in a third-floor apartment, so weight is very definitely a factor.
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Yes, with cheap third world labour, the same way many other technological marvels of the modern era are "automated".
This can't be done remote so you will need to bring that labor to where the work is.
There's already a pipeline sending old electronics to cheap labor for possible refurbishing, recycling and/or incorrect disposal. A small percentage they repackage into replacement laptop batteries and ship back, but they could also send more of them back as a value UPS with different value add parts.
Personally, I expect there to be a massive conversion to USB-PD as the primary power in the cellphone only regions.
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Building large battery arrays out of old recycled cells does not require bringing the workers to the battery cells, any more than building iPhones requires you to bring the workers to where they mine ore. Large-scale product development often involves shipping materials and half-finished products around the world multiple times.
You would never do this in a production product. You need batteries with similar internal impedances or undesirable things happen. This is the battery equivalent of the guy who welds two car front ends together and drives it around. It's cool and quirky but not a useful product for most people.
From what I've heard, it is more economical to recycle the raw materials than to reuse small packs.
Reuse of vehicle sized packs seems to be pretty common, though. I'd guess that a DIY home backup could be built pretty easily from used vehicle batteries.
The dude has a warehouse/workshop to do this work and house the system. I’m super impressed by what he’s accomplished, don’t get me wrong; but, what he’s done just isn’t viable for 99.99999999999% of people.
Give me an array and battery system that can pull off the grid and/or array and power most of my home without me having to think a whole lot or pay a vendor thousands to install while making the total cost under $1000 and I’ll do it.
Until then, it just isn’t financially viable when my electricity costs are well under $70/month average across the year.
Recouping the costs for install of solar systems are estimated at 30-40 years as of 4 years ago when I researched it. I’m sorry, but that’s just not worth it for me and most others.
I enjoyed noticing that your percentage (1×10⁻¹³) was so precise that it excluded the man himself (he is 1 in 8×10⁹).
I don't want to detract from your point. I just wanted to appreciate the hyperbole.
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Sure, but it does get a lot simpler if you start from modules instead of cells. Nothing will get around the requirement to have electrical knowledge.
Cost is always an issue. These rarely make sense from a pure $$ sense, as everything in electrical is expensive. You could burn up that $1000 budget just to get a subpanel installed.
Usually the value proposition is some combination of savings, combined with the ability to backup critical loads. A generator could do that too, but a proper generator setup isn't cheap either, and it wouldn't save $$ at all. Battery solutions sometimes beat that.
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Buying a used Nissan Leaf and using V2H feature in CHAdeMO is it. Or you can remove and use its well-reverse-engineered minimum nominal 24kWh semi-removable battery. But no one wants a Leaf, so there's that.
Of course, but you will also 'scale' the safety implications.
Standardizing battery packs would probably help with the automation; like with USB-C.
Isn't the problem with parasitic charging? Suppose you had a bunch of used 18650 cells. To scale the electronics, they'll be wired up in parallel and/or series so the charging logic can be shared, but since the batteries are wildly mismatched, it results in parasitic charging.
That is why you sort them.
Some recent research into that: https://www.sae.org/publications/technical-papers/content/20...
You can also consider maintaining packs together to avoid complicated disassembling processes.
> maintaining packs together
(This might already be happening, but I haven't heard about it) The big thing EVs need right now is standardized battery packs. It reduces replacement cost, takes away anxiety that a replacement will exist when you need it, and enables down-cycle uses like stationary storage.
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But will the scale justify the huge investment?