Try Batteries Plus.....if no Kymco dealer near. OEM always seems to work best for me, long haul.....and I do not mind changing out batteries (if I keep bike that long) every 2-3 years as I hate walking....no kick start/bump start scooters make one think.
As I ride daily year round, regardless of where I am, do not have battery problems----as I get older wiser, I tend to keep only one bike at a time, so using bike not problem----at one time in Germany I had 8 registered/running bikes/scooters......real pain keeping them running and clean.