Welcome Kymco Owners!
Replaced mine with a liothium a couple of weeks ago. I like ti. It works a little differently in that it likes to be warmed up before starting. Turn on key and leave lights on for up to 4 minutes in cold weather. 30 seconds in warm. No battery tender if it's started once a month. Costs more, and lasts longer. MIne came with a 5 - yes that is five - years warranty.
The instructions say if it's run once a month, that is enough to keep the battery charged without needing a battery tender. It seems to be a little stronger on startup over the stock one.