I know the guy is not using cheap Chinese parts, as they're not reliable enough. He said he's only using Japanese cells. I didn't crack open the battery pack to see if that's true though. :)

DiscreetFX could say something about quality of this work, as he happens to own a PowerBook with battery regenerated this way.

@amigadave:

I believe the MacBook battery won't physically fit into a PowerBook (don't know the exact size, but the locking clamps look clearly different to me).

I also believe that it's the cells that swell inside a battery pack. If you could get rid of the broken cells maybe it would be possible to revive that battery? Do you have a photo of the damage?