The OP failed to mention how old the batter is. If 4-5 years old, I would toss it and replace with a quality AGM battery; simple, one and done.
However, if only a year or two old, pull the battery, take it to Advanced Auto or Auto Zone and have it load tested. If the load test shows the battery to be serviceable, put it on a charger (not a trickle charger) until fully charged and reinstall. By serviceable, I mean meeting the original performance specs for that battery; anything less, toss it. It will just fade away and likely leave the OP stranded somewhere. If the battery tests out OK, reinstall and keep the battery on a tender at all times after that and the OP might get another two years out of the battery.
It is not easy to bump start these vtwin motors, if there is any doubt about the integrity of the battery, replace it and avoid getting stranded somewhere. Get a tender and keep which ever battery used on a trickle charge at all times. A new battery kept on a tender will last five years under most circumstances.:s