Intermittent starting problems

I have a 2011 Suzuki GSXR 750 my charging system checks out fuses and relays but every now and then I will go to get right back on the bike and it sounds like my battery’s dead the motor drags when it tries to turn over I can push start it but I need to get to the bottom of this problem besides the starter two fuses in the starter relay what should I be looking for the clutch switch, kickstand kickstand switch, why would it make the engine sound like it’s drag down and the battery is week