/diy/ - Do It Yourself

>>2040655
Yes, but usually it's not possible. By the time a laptop battery is "used", it's usually trashed.
Newer batteries are flat polymer cells, older ones have 18650s. In both cases the tabs are usually spot welded. It's possible to cut them, carefully, and even solder to what's left of the tabs.
This one is from a Chromebook battery, I thought it might be toast, measured 1.9v when I found it, but it holds its full rated 3AH capacity.

Slashing up laptop batteries is hardly the best way to get 18650s, but it might be a decent way to get flat cells.

If you want to use the entire battery, you can implement the Smart Battery SMBus protocol using an arduino or something.