Some time ago a buddy of mine gave me an old laptop battery of his. He knew usually not all the cells are bad, one or more can be salvaged and used for other purposes. I can't sleep for whatever reason, so I absconded to my mad science workbench in the garage to crack this bad boy open.
Of course there aren't screws or anything, because then life would be easy and we can't have that. Instead I had to absolutely fucking demolish this thing to get it open. It's almost as if they don't want people replacing the cells themselves or some nonsense like that.
There's all the cells removed. Still taped together in pairs, and still soldered together at the tips. The connections are remarkably weak, it doesn't take much to pry it off completely. Then the cells will be ready for their new lives in my service!
Okay, there they are all untaped and with the connections ripped off. All that remains is to test them individually with a multimeter to see which, if any, can be salvaged. Generally a voltage below 2.5 means it's irreversibly fucked. I've seen some tutorials purporting to show how to revive cells discharged to this degree though.
Hoo boy. Haha. Well, that's not good. But hey, I assumed going into this that not every cell would be a winner. What are the odds they're all dead, though? Even I can't have such bad luck.
(Narrator: "But as he discovered, testing the cells one by one, he did indeed have luck that bad. Never again would he be so naive as to hope for anything but the worst possible outcome.") Oh well. Looks like I'll be needing those tutorials after all.
Out of the lot, only a single cell tested above 2 volts, and then only barely. It looks like I'm going to enter uncharted territory soon, making use of forbidden, arcane techniques pioneered by DIY power wall builders to revive these cells.
Is it really possible to revive a cell in this condition? I've seen stranger things. You'd be amazed at how far gone a lead acid battery can be, but still be revived, for instance. Anyway stay tuned, I'll do a followup with the results of the cell resurrection experiment. If there are no posts after this, the cells caught fire and burned my house down with no survivors. AVENGE ME!
Stay Cozy!