Tried charging the battery and got good voltage with volt meter around 12.5. Tried to start it and nothing, the voltage dropped to 10.5 after that. Does anyone know whats causing the voltage to drop or whats draining my battery. I had this problem when I first bought the bike in May. A new Yuasa battery fixed it and no problems until now.

After charging the battery when you hit the starter did the engine turn over?

If not put the bike and first gear and push it backwards to turn the starter motor over. Then back in neutral and try the starter and see if the engine turns over.

12.5 volts is not great btw. It should be over 13 volts on a full charge with no load.

Same thing was happening to me it turned out two things was causing it

first was the voltage regulator , I was getting voltage of 12.5 changed the regulator shot up to 14.

second was the ecu for some odd reason moisture was getting into contacts ( rain or washing ) and bike would not start the next day battery would show low voltage . I to would change the battery temp solution
I would have the voltage regulator checked and make sure the ecu is properly seated and perhaps seal it so moisture will not get into it