I used to have to replace the lead/acid battery in my Harley about once a year, even when using a maintainer on it, mostly due to lack of use. Over a year ago, I replaced the battery with an AGM type. I start the bike about once a month and run it for 20-30 minutes since I haven't been able to do much riding in recent months while caring for my wife. The bike cranks up and runs flawlessly- - - - -no maintainer needed!
Jerry