The practice of opening up the
battery cover on a
remote control when it stops working and rolling the batteries with the tips of your fingers, in a bizarre ritual that we somehow expect to breathe new life into the obviously dead devices.
However, this practice does in fact work to some extent; the rolling of the batteries warms them up a little, and introduces a little
kinetic and
thermal energy, thus increasing the
reaction rate, and generating more
electricity to power the remote just a little longer. Also, the problem may not be that the batteries are
flat, but that a layer of
oxides and
dirt has built up on the
terminals. Rolling the batteries can remove such a layer, and improve the
contact.