Motorcycle Repair: Honda not charging, regulator rectifier, rectifier unit

Question
I have a Honda Magna, I recently purchased a new battery, followed the instructions on charging the battery, rode my bike twice and this morning the battery was dead.  What is the most likely cause of this?  I have ruled out a bad battery because I already switched it out.

Answer
If you are absolutely certain the new battery was fully and properly charged, I would suspect one of two things - either there is an electrical leak to ground that is draining the battery after the bike is shut off, or the regulator/rectifier unit is fried and needs to be replaced. If you have access to a voltmeter, start the bike and place the leads on the battery terminals. If the reading is 14-16 volts, the regulator rectifier is working (when you shut the bike off, the reading should drop to 12 volts).

If that is all okay, then try disconnecting the battery positive cable before leaving the bike overnight. If it starts no problem the next morning, then there is a fault somewhere in the wiring that needs to be fixed because it is causing the battery to drain itself when the positive cable is connected to the battery and the bike is shut off overnight.