←back to thread

Glubux's Powerwall (2016)

(secondlifestorage.com)
386 points bentobean | 2 comments | | HN request time: 0.949s | source
Show context
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.

replies(6): >>43549197 #>>43549208 #>>43550703 #>>43551134 #>>43551753 #>>43562271 #
supportengineer ◴[] No.43549197[source]
There HAS to be a way to automate this process and make it work at scale.
replies(11): >>43549383 #>>43549397 #>>43549447 #>>43549497 #>>43549521 #>>43549609 #>>43549625 #>>43549952 #>>43550129 #>>43550429 #>>43551649 #
joshvm ◴[] No.43549397[source]
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?
replies(6): >>43549465 #>>43549535 #>>43549883 #>>43550510 #>>43550616 #>>43550707 #
0_____0 ◴[] No.43549883[source]
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.

replies(2): >>43550211 #>>43550821 #
lifeisstillgood ◴[] No.43550211[source]
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

replies(4): >>43550513 #>>43550819 #>>43551366 #>>43552522 #
1. kadoban ◴[] No.43550513[source]
There's a lot of risk in creativity when you're selling crap to the public at scale. Way better to just use what everyone else is using.
replies(1): >>43552573 #
2. 0_____0 ◴[] No.43552573[source]
For most things cylindrical cells are the right answer. They don't puff up, they're available with protection circuits, they're cheap and highly available, you can get them in a variety of sizes and capacities, even in different chemistries.

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.