BroJack wrote:
Instead of the quiet whirring sound of a fan when in float stage, the
charger has recently begun emitting a louder "whining" sound. The
fan's revolutions also seem to slow down when this happens. It
returns to normal if I insert a finger quickly and contact the fan.
But it often resumes "whining." At this moment, it's nice and quiet,
but the noise mode is occurring more frequently?

Is this damaging or dangerous? Does it need a new fuse? Thanx, Jack

Well, you found the problem, the fan bearings needs some
oil. Unless you fix it, it will seize one day, maybe burn
out, possibly start a fire, but unlikely. A new fuse will
do nothing since it is already working (getting
electricity). Why the hell would you have a fan in the
charger, or is it a separate fan that goes on when the
batteries charge?

Take the charger cover off, put 2-3 drops of 10 weight oil
(or Turbine oil if you have some) on each end (bearing) of
the fan motor, spin by hand, blot to remove the excess oil.
Probably will fix it for another few years. Otherwise,
buy a new charger/fan. Whatever floats your boat.