I was gonna say you have a bad battery but it looks like that you figured that out.

 

Glad you got it resolved. There should be a warranty on that battery if it’s only 9 months old. I thought you were on a touring model. I guess I should have looked closer. Some of my advice would not apply to a sporty.

 

I had the same problem this Spring on my 2000 Wide Glide. I had put a new battery in last Summer and it never showed any sign of getting weak but I went out for lunch one day and after I ate, went out got on the bike and had the same symptoms. I jumped it with a small power pack, got it home and put it on the charger. Later it showed fully charged but with ignition on it would drop to 0 volts, on accessory it would show 10-11 volts, off it would show 12.6v. After cleaning the cables and checking everything I went and had battery load tested. It would show full charge until load was applied then it would drop to 0.

I have no idea what caused it to crap out all at once while I was eating lunch but I replaced it with a new, different brand battery and it has been fine ever since.

 

Thats pretty much what happened to me except, for the exciting part about lunch. Lol . I purchased the bike a few months ago and it had a new battery, apparently it was a chaep off brand battery.