It should still have 87W through, might heat up a tiny bit more, but I really, REALLY doubt that a power cord rated for 60W would be unable to handle 87W too, t

It should still have 87W through, might heat up a tiny bit more, but I really, REALLY doubt that a power cord rated for 60W would be unable to handle 87W too, the safety margin would be way too low. Also, your dramatic learning experience is dumb, shorting a car battery will do probably do a few hundred amperes, two orders of magnitute more than in any laptop charger ever...