I had engine and battery light on last week code was for low voltage, checked battery and tightened up on battery terminals. No problems, about 400 miles since.
Since you only have 900 miles, I bet it is a 2012. Your voltage regulator is going out. This is a known problem on 2012 bikes. If the dealer has never heard of this, they are really small or lying...Tons of threads on here. Do a search...
Every thing has checked out on the voltage regulator and stator they are calling harley today
Mine would do it when I had been stuck in traffic. Once I got rolling again the lights would go off and everything would work fine. I was suspected the VR was getting heat soaked sitting right above the oil cooler and shutting down. I took it to the dealer and they tried and failed to get it to do it in the shop until they put a heat gun on the regulator and it shut down. They replaced it and I haven't had any problems since. (still crossing my fingers)
I'm over here in the desert and my scooter is in storage at the dealer so I can't put any miles on her again until I get back home around Christmas.
we were out riding a lot of stop and go on the way home saw the check engine and battery light on and volt meter was on 12 volts drove it to the dealer and shut it off waited for the service advisor to come and went to start it and lights are out and charging about 14 volts drove home 45 miles and never came back on