Anybody have a recommendation as to what type of tester I should use to check the voltage on the battery of my 2005 Fat Boy?

 

i delieve what your looking for is a "multi meter". steve

 

You might wanna load test as well.

 

If your just looking to see how much voltage its putting out or how much voltage is being put out by the alternator when its running, a good old multimeter will work fine.
If your looking to see how well it works under a load your going to need something a bit different and its easier to just take it to a local auto parts store like Advanced Auto or Auto Zone. Pull off the seat and let them test it for you, its generally a free service so you have nothing to loose.

 

if the battery is over 3 years old change it