My starts when it wants an when it does not I drive the voltage meter tacs out n lights flicker dash lights come on I loose power an I'm afraid that the battery's going to explode any ideas

My dad's my 97 Dodge Ram
is over powering itself the
voltage made it tact out I test
the battery it's at 18 volts all
the dash lights come on the
lights flicker that I shut it off
sometimes it'll start and then
sometimes it won't start till
the next day any ideas I think
it's the camshaft sensor or
the cam shaft position
sensor I don't know which
one it two different ones