I don't leave mine fully charged all the time. The recommendations in the Zero SR/F 2020 manual, seem to be in-line with how I maintain my batteries.
Remember; Even if you find a shop close enough, you'll often have to recharge to get back home. Three places where I used to take mine for service, no longer work on the Empulse. I know a small shop, ArneysGarage, that seems curious, otherwise I'll have to rely on myself.
I see the bike you found on Craigslist, Good Luck =)
CyberG from SoCal
Proud Brammo Empulse 2014 Owner, When it Works =/