Pretty sure the original was a acid based, wet cell type. Kaw wasn't going to spring for AGM type batteries.Try ebatteriestogo.com. they have what you want at a good price. It is a jell battery and is same size as the original. When I bought mine there was no shipping or tax on the item. It may still be the same.
Any place I've ever got a battery from adds a core charge to the new battery, which is returned to ya once you bring the old battery back to them. Usually about $5-$8.Only issue is disposing of the old battery, I still have the old Yuasa from when I got the Vulcan, the HD battery (also a Yuasa) has to go when the new one comes in. Found out our county has recycling centers which will take them.