Rejuvenate a weakened magnet by rubbing it against a stronger, more powerful magnet for a few minutes. The stronger magnet partially realigns the electrons of the weaker magnet and restores it to at least some level of its former strength.
A home remedy for rejuvenating weak magnets calls for placing them in the freezer overnight or longer. The cold temperatures affect how electrons move around the nucleus of the magnet and restore it to some extent. Other methods include removing the magnet from any source of heat, which has the opposite effect of placing the magnet in the freezer, and keeping the magnet away from electrical appliances that can emit electromagnetic waves that interfere with the ability of the magnet to maintain its charge.