2008 R6. Battery discharges completely when allowed to sit. Owner replace four batteries. Voltage checked with bike at 5000 RPM and is charging (14.4 V). When the bike is put on a Battery Tender, the charger light will never go completely green. Upon disconnecting the bike and connecting the Battery Tender, it will turn green indicating a full charge. I am thinking voltage regulatory however am not familiar with this component causing a problem if the bike is not running.

There may be an intermittent issue developing with your voltage regulator / charging system. Eventually it will fail if not corrected or replaced. Once a lead-acid battery measures 11.7 volts (open circuit) or 10.5 volts (load connected), the battery is considered fully discharged.

You were pretty close to the discharged threshold and if you stopped when it read 11.8 volts, I doubt the battery would have been able to crank over the starter. You should have the charging system checked out.

the battery may seem ok, but it's obviously discharging itself or not charging during riding.

Try this...charge the battery with a battery charger.
disconnect the charger, and put a volt meter on the battery.
Start the bike.
Rev up to 2000 RPM. If the voltage is not HIGHER than it was before starting the bike, there's something wrong with the charging circuit.
If it IS charging, turn the bike off, and disconnect the battery overnight.
If the bike will not start the next day after reconnecting the battery, the battery needs to be replaced.

If the battery is NOT charging at 2000 RPM, the charging circuit is bad, and is likely what is draining the battery overnight.

sir, its location is under the fuel tank near the air filter box...

is battery more than two years old? if yes replace battery. Battery voltage should be >12.4 volts minimum. if it wont hold this charge its bad. Check all the wiring on your bike to make sure that you dont have a shorted system that is draining down you battery.

Don't rely on on whether the bike will start at a gas station to determine if the charging system is working. Get the multimeter out and do a proper test. Should be getting about 14.5 volts @ around 3K RPM. It's too easy of a test to to just skip. If it is charging then start looking for something else. Was the new battery properly charged to begin with? Loose battery connection? I suppose the GPS could be too much but you said that it was dying last november, so I would suspect something else. P.S. you need a properly charged battery to get an accurate reading for the charging test.

came out of the coffee shop went to start the bike and the battery didn't have enough power to turn over the motor....I pushed started it but it didn't want to stay running once I put it in gear. Last night charged the battery and today put it in the bike and it started right up....rode it for about 45 minutes waited for about half an hour before starting it up again and it started , no problem. I am thinking that maybe it is the voltage regulator or maybe the alternator....can anyone help me out with this? ,If you have a multimeter, you need to test the electrical output of the charging system. (Check the voltage of the battery when the bike is revving at about 2000 rpm) If you don't have a multimeter, the best thing to do probably is to take the bike to an Autozone or similar car place where they will test the battery and charging system for free,,,