Call me a COB...I'm OK with that!
Don't really need the special charger - a Battery Tender will work just fine. Part of the issue is you just don't need to charge it unless you run it completely down. Just sitting idle it doesn't run down for 6 months to a year. Don't think you ever want to charge a m/c battery faster than a Battery Tender does. I've got 2 years on mine and have never used the expensive charger that I bought out of fear.