Here's a video inside a recycling plant: https://www.youtube.com/watch?v=s2xrarUWVRQ
$50 of 18650s in a $500 trenchcoat with DRM protection. So wasteful.
We are well past the point where we should have standardized batteries. We have bunch of standardized wall outlets that accommodate an array of "non-zero chance of literally killing your users" end products. No reason for battery packs to not be standardized (other than vendor lock in).
You're also wrong about standardization - standarization at the cell form factor level is correct. Different applications have different capacity vs power density requirements, temperature range requirements, cost, lifecycle... a pouch cell that goes in a drone looks a lot like one that goes in a cell phone but they're optimized for completely different workloads.
Also we already have standardized interfaces for external batteries with most power banks using USB-C, so in a way your wish has already come true.
https://www.protoolreviews.com/doge-mandates-power-tool-manu...
Probably the only thing I can agree with doge on.
Linus from Linus Tech Tips made a few episodes on building a battery out of individual 18650 cells, and one of the thing he stressed (as in, underlined) a lot on is that spot-welding cells is extremely dangerous and there aren't easy ways to put out a lithium fire.
Water is not only not going to help you, it's going to make things worse.
You __have__ to have a bucket of sand with you and if anything goes even slightly wrong you just toss everything in the bucket of sand and bring the whole bucket outside.
Yeah burying a thing in sand is legit. Depending on the size of the thing that's on fire, water might be fine. Standard protocol for electronics that catch fire on a plane is to apply water to cool the device and extinguish materials around it, and then to put it in a special fireproof bag with a bunch of water.
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 just assumed there was … special stuff in there
Using a custom cell might make sense if you are making a) one megakajillion of a thing or b) you have extreme volume limits which mean you're probably using a pouch cell.
In HW engineering, Not Invented Here syndrome costs you big money. You have to have an actual business case for re-engineering something that already exists plus the capital.
95% with my stuff of the time COTS cylindrical is the answer, which means my shit comes in on budget.
Soldering some connectors onto some random cells and knowing they shouldn't go over 4.2v is one thing, but measuring cell health via internal resistance, programming a controller to do temp shutoff and wiring up temp sensors, keeping cells balanced, is a lot of extra work, but critical if you at all care about not potentially burning down wherever they're stored.
Keeping the cells small and just using a hundred of them in parallel (and a hundred of these parallel packs in series to get up to the hundreds of volts needed), thus using ~10,000 cells, in EV batteries limits the maximum damage from one cell going worst-case, assuming your enclosure can contain it.
That being said, it seems there is a slow movement towards larger cells, from 18650 to 26650 or similar. But each cell on its own is still a dumb can of chemicals ready to go boom if you mistreat it.
Don't, uh, buy those unless you're sure.
Also with bigger packs inter-cell consistency is really important (good cell integrators will test and bin them by ESR even if they're from the same lot, and using a really reliable cell mfg/vendor is critical because you're selling expensive systems with a number of failure points that scales with the number of cells and you want their process development to be super mature.
Was definitely one of the harder parts of our solar install to get comfortable with.
(IIRC, these packs are 16 100ah LiFePO4 cells in a steel case w/ built-in fuse, breaker, and BMS that monitors individual cell health and pack temperature, w/ automatic cut-off if any of that goes out of spec. The weakness is primarily the MOSFETs on the BMS potentially failing shorted. Fortunately, they've added some sort of additional fire suppression beyond just "steel case" in recent-ish versions of these packs)
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.
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.
If you reduce the energy density by a factor of 10, the weight for power backup needs will still be far lighter than the concrete.
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?
Larger batteries, including some electric cars, have switched.
https://cambridgerenewables.co.uk/product/eleven-energy-4-5-...
Personally, I expect there to be a massive conversion to USB-PD as the primary power in the cellphone only regions.
And yeah - some LEDs and a usb wire around the ceiling solves lighting a house more sensibly than a three-phase converter under the stairs and enough power going through a light switch to kill me …
It's why you can charge your phone with your laptops power brick without anything exploding, and why most laptops can charge (very slowly) from pretty underpowered phone chargers now.
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.
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 don't want to detract from your point. I just wanted to appreciate the hyperbole.
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.
But net metering is becoming less common, and if you can't sell to the grid at retail, then it'd make sense to store it locally. In some cases, it can also make sense to use batteries even without solar. A good sized battery can keep your refrigerator running for days, which is useful for areas prone to weather related outages. It can also easily fully power the electronics on a gas oven for a long time. And honestly, a big battery these days isn't even that expensive.
And if that isn't enough, some batteries can be topped up with the power from a large battery EV. DCFC tends to come back before a lot of residential power, so this can be really useful.
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.
(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.
Certainly a standard form factor for a pack would be helpful for a specific manufacturer (similar to building multiple cars on top of the same basic frame).
Some of the issues I think one runs into is battery chemistries are rapidly changing so even if the shape of the pack remains the same the performance of it is rather different depending on what is put inside.
Then even with standard form and chemistry one pack to another can be rather different depending on the history of it's use (age, charge cycles, driven hard).
There is second life storage applications currently, and still more research going into it now.
Personally I think smarter controls and smarter diagnostic and pack sorting will be more useful.