alt Hacker NewsYou 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?
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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.
> 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.
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'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.