Posted by bentobean 1 day ago
>Glubux even began disassembling entire laptop batteries, removing individual cells and organizing them into custom racks. This task, which likely required a great deal of manual labor and technical knowledge, was key to making the system work effectively and sustainably.
This kind of thing is cool as a passion project, but it really just highlights how efficient the modern supply chain is. If you have the skills of a professional electrician, you too can spend hundreds of hours building a home battery system you could just buy for $20k, but is less reliable.
That is, in my opinion, the worst feature of this entire project. It is cool and nice and fun. But it takes a lot of time to research, acquire skills, get tools and build.
> you could just buy for $20k
I agree with a broader point but that particular price is extremely high and far from reality.
A reasonably good 18650 cell has a capacity of ~12 Wh (~3300 mAh * ~3.7 V = ~12.2 Wh). The battery mentioned in the article consists of "more than 1000" such cells. Let us assume 1200 cells. That would mean it has a capacity of ~14.4 kWh (1200 * 12).
It is possible to get a pre-assembled steel battery case on heavy-duty wheels for 16 LiFePo cells, with a modern BMS with Bluetooth and wired communication options, a touchscreen display, a circuit breaker and nice terminals for ~ $500. And it is also possible to get 16 high quality LiFePo cells with a capacity of ~300 Ah each, like EVE MB31, for significantly less than $100 each. This means that for less than ~$2000, it is possible to get all components required to assemble a fully working ~15 kWh LiFePo battery.
- That assembly would take a few hours rather than weeks.
- It will have new cells rather than used ones.
- It will be safer to use than a battery with Li-Ion cells.
- It will likely take much less space.
- It will be easy to expand.
I will point out that in 2016 when they started this project, the cost of new batteries would have been multiple times higher than it is today, so it would have been a moderately more "sensible" thing to do than it currently seems.
I can imagine that ~9 years ago there might have been very little reasonably priced LiFePO4 cells available and if someone could get their hands on used 18650 cells very cheaply, it might have been a reasonable choice at the time.
At least if he bought a commercial battery and it experiences a lithium fire, he might expect to file a claim against the manufacturer, or his insurance company might on his behalf.
$80 per cell (before shipping) on the top Google product result for EVE MB31.
That's a good bit cheaper even than when I looked last, in early 2021.
It just keeps getting cheaper and cheaper every year...
It was shipped from China so I had to wait ~2 months to get it which is a disadvantage. Local warehouse stock was slightly more expensive.
https://travis.vc/mexican-fisherman-parable/
Sometimes the doing is the fun part.
This is not a feature. Our Earth is a limited resource, and being able to reuse batteries instead of discarding them to the trash is a desirable property.
OTOH used laptop batteries can likely be obtained for effectively zero monetary cost, while used EV or solar backup batteries still cost quite noticeable money per kWh. With laptop batteries, you pay with your time; if you for some reason have an excess supply thereof, or you just enjoy this kind of work as a pastime.
Of course. No one disputes that. I was just trying to point out that you can get better cells for less money.
> being able to reuse batteries instead of discarding them to the trash is a desirable property
I fully agree. No one is trying to suggest that we should discard used batteries into trash.
DIY (like this project) is only "worth it" if the person doing it enjoys the work or values the lessons.
Battery packs are an efficient market commodity and that’s pretty hard to beat for value for money.
Once full installations become more of a commodity then DIY with premade packs becomes less worth it.
He made more than he would have working retail for sure, but maybe he could have done better with another job if he weren't fixated on sticking it to the Man.
This battery thing feels a bit like the same sort of sentiment.
That said, any task you can do while talking to a friend or binge watching a TV show cannot be accurately accounted for in cost by just how much the clock moved.
This "efficiency" relies on the assumption of writing off the entire battery set at sale. That's not impressive at all.
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.
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)
I just assumed there was … special stuff in there
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.
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.
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.
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.
Larger batteries, including some electric cars, have switched.
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?
https://cambridgerenewables.co.uk/product/eleven-energy-4-5-...
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.
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.
And with even more passion and commitment and with business skills, you could earn $20k at a time.
https://secondlifestorage.com/index.php?threads/glubuxs-powe...
^ has a wild picture of full setup
A roof-mounted water tank with a thousand gallons ready to dump into the shed? A drum of baking soda?
Or maybe rebuild the shed out of cinder block and clear any overhanging vegetation?
Maybe this whole setup is on desert dirt with plenty of clearance. The fire plan is "run away and wait."
You could also just bury it so that the worst of the explosion is mostly mitigated. I've also seen small container setup which would probably work better than his (seemingly) wooden shed.
Would be better if the ground was paved around the shed, but it seems to be far enough from other free standing structures.
[0] https://secondlifestorage.com/index.php?threads/glubuxs-powe...
[1] https://secondlifestorage.com/index.php?threads/glubuxs-powe...
The extinguisher should be directly inside the door so as not to attract someone to traverse farther into the building without an escape plan.
Of course if he did so then there would be no extinguishers in the picture and then we would also bitch about it.
If he can't reach to grab it because it's too hot, he should have already left.
If you are outside, it does not tempt you to cross the room. If you are inside, you run for the door, and then turn around and decide if maybe you should just keep running.
Dry Powder or CO2 is what you need for energized electrical equipment. And considering there's potential lithium involvement, you might want something more specialized (e.g. F-500 Encapsulator Agent). I agree anything more than a small-scale incident you're just getting the heck out of dodge. I'd have built something along the lines of a concrete bunker, with an automated suppression system to buy time.
There's no protection over the bus connections. Any falling conductive item is now a spark hazard.
Using spring loaded alligator clips as test leads apparently for monitoring. I hope that's not a permanent configuration.
Everything is bolted down and I see no inline disconnects or even any fusing except on low voltage sections.
There are exhaust fans but I can't tell if there's inlet fans.
From this one picture, which may not be fair, this is not a safe setup. I would feel uncomfortable with this on my property.
The firemen ended up putting the battery, half melted, into a big drum of water and it hook hours to cool off. The concrete was still warm to the touch where it burned for ~30 hours after the situation was sorted out.
The smoke was just absolutely unbelievable. Made me reconsider buying an EV. That fire was no joke.
The MV contactor wasn't even closed, it had 24v powering it for the internal cell balancer from the vendor, that was it.
The hazard appears to be accounted for.
The infamous Samsung note 7 exploding battery catastrophe was 90 incidents out of 2.5 million phones, or 0.003% exploding.
That said, one should be prepared for it.
They do swell, but they swell at the terminals rather than at the sides.
Also the guy who made this battery pack has the incentive to not burn down his house, whoever made yours has the incentive of one more day on the assembly line… I dunno, wouldn’t judge him too harshly.
Those scooters in the streets get discarded/buy em in bulk and re-use the batteries for ex
They are rather short and show the setup more than the construction and nitty gritty, IIRC
But they were as much of a fire risk (if not more) before being recycled, they were just spread out along the e-waste bins!
Every time I hear of a waste processing plant fire, I wonder if there was a (lithium) battery involved. Maybe from a single use vape, or a child's toy.
If it could be done, would certainly would be better than turning batteries into "black mass."
The safety risks are marginal and you interact with plenty of other things/systems daily that are at least as dangerous.
> here are safer battery chemestries that aren't quite as energy-dense ^ that's the answer.
> But phones and laptops were capable-enough 15 years ago They absolutely weren't.
> we sufficed just fine on the performance of last-decade's mobile devices. I don't want to suffice.
All that said, I do think battery research is probably one of the most important things "we" can be doing (and energy storage in general), so I'm all about putting in the money and time to find improvements.
Everything has risks — its about managing them. Lithium ion batteries are widely used because their benefits outweight the risks when handled properly.
Its like saying, “Why are candles still legal? They can start fires.” Well, because people know how to use them responsibly.
Why do we still let kids go outside when there are so many kidnappings?
The samsung battery debacle around the note 7, which made headlines for weeks, was from 0.003% of phones catching fire.