Korishan said:
Use side cutters to trim as close as possible.On the positive end, you could rip them off. However, the negative end takes a bit more fineness and is more fragile as you could rip a hole in the casing.
I suspect I've salvaged more tool batteries than anyone else...
... and yes, I agree, you can banana peel the positive terminals off just fine. The negatives you can't, as the nickle connector strip is as thick as the cell casing, and it's 50/50 which side the weld nugget rips from, with 4 spot weld per battery you're almost guaranteed a puncture followed by a hiss-and-piss.
The same will happen a significant portion of the time if you try to use flush cutters. Any type (I'm a plier and side cutter snob, I must have 50 pairs of each).
The only consistent method I've found, is a narrow chisel, and whacking it 3-5 times lightly with a light hammer (light enough it bounces, like, 1/4 the weight of a normal claw hammer, plastic head ideally). You don't want to force it or try to get it all done in one blow, you don't want to cut or catch the chisel into the surface (it will, and it will start to cut into the case). You almost want to shatter the weld with a bouncing motion so the blade settles against the actual weld nugget, not the case. Like you were holding the edge of a frisbee and hammering with the flat of the plate. Bonk bonk bonk bonk bonk.
You want to avoid peeling them, only enough to get the chisel in, as that creates a little lifted peak out of the case around the welds, which then the chisel will cut through and puncture. It took me, I dunno... 50 or 100 or so before I got the right touch to not be cutting holes in them. My failure rate at the start was like, 30%, but it quickly dropped off to nearly 0%.
I've been meaning to make a full tutorial on disassembling tool batteries, but, lemme spackle together a quick demo from old footage:
It was hard to demo on the ground, and the desk/cardboard takes up too much of the impact. You want it held solidly. The second one is typical. I normally put a 2x4 on the ground, and then the cell on the 2x4, with my shoe stepping on the cell to hold it steady instead of using my hand like I did in the video. Then tap-tap-tap-tap-clink. Repeat. Faster than using cutters even when that's an option.