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Glubux's Powerwall (2016)

(secondlifestorage.com)
386 points bentobean | 7 comments | | HN request time: 0.837s | source | bottom
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ianferrel ◴[] No.43549073[source]
>the solution came with rearranging and adjusting the cells to ensure the packs worked more efficiently.

>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.

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pbasista ◴[] No.43551134[source]
> spend hundreds of hours building a home battery system

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.

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1. fragmede ◴[] No.43551200[source]
> - It will have new cells rather than used ones.

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.

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2. beacon294 ◴[] No.43551348[source]
There's even more to the riddle. Lithium recycling, cost of the power loss in old cells. Power transmit cost. Cost of power generation on site.
3. nine_k ◴[] No.43552214[source]
Pick used EV or industrial batteries. This must be much more efficient due to a larger cell size than in laptops.

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.

4. UltraSane ◴[] No.43552388[source]
We have LOTS of lithium
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5. awwaiid ◴[] No.43553154[source]
Maybe we'll run out of ion?
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6. nine_k ◴[] No.43553824{3}[source]
Sort of. Compact NMC Li-ion cells from laptops and phones often use stuff like cobalt, supplies of which are much more limited and problematic than of lithium. The newer LiFePO4 chemistry does not use it, and, importantly, is rather hard to ignite. Its energy density per unit mass is lower, but it's not that important for stationary installations.
7. pbasista ◴[] No.43557768[source]
> Our Earth is a limited resource

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.