My SV keeps draining batteries sitting for just a couple days. Replaced battery with new AGM full size and still happening. When changed battery is installed it fires right up and runs all day without issue. Possible clue- I turn ignition on and when the gages do their tach sweep the tach stops at 7K for a second before going all the way up then back to zero.
You've got a parasitic loss. Something is still drawing when you shut the bike off. Find that and you'll fix the issue.
Parasitic draw losses are fun. (not). Connect an ammeter to the pos circuit from the batter (in series). Dial the range down until you can see the current drain. Disconnect things (meter, pump, etc.) until the current drain goes away. then you will find the drain.
Check for a stripped stator bolt... had the same thing happen on my GSXR.. turned out the bolt was stripped and prevented the spin..