OT subject with jumper cables

So I buy a new computer and want to donate my old one. What would happen if I connect jumper cables from my car battery to the hard drive to try and wipe out all the stored information? Most information can be recovered from a clean or wiped hard drive. Thought this may do the trick.

stick it in salt water :thumbsup:

no matter what u do some info will be there unless u go with what i just said...but just bleach and reformat ur harddrive and be done with it...