Most battery tenders come with a 8" pigtail that you connect to the battery permanently.
It has a 2-wire quick connection, like used for trailer tail/brake lights, to connect to the tender.
I use a 12" extension connection to run out from under the seat to near the rear shock for accessability.
When not in use, I pull it up into the under-seat storage area.
Real tenders can be left hooked up all winter, but I prefer to check my batteries monthly.
That way I can tell if a battery is going bad;
if the internal resistance of the battery is decreasing, the battery will need recharging more frequently or for longer on the charger.
A good AGM battery probably only needs to be hooked to the tender 1/month for about 30 minutes.
A standard battery is more like 2 times/month.
REMEMBER to check the fluid level in regular batteries and to use Distilled water if needed.
Happy New Year & Scoot Safely,