This isnt a battery issue man...this is a user issue...if u know ur bike is unused for 2 weeks or more u should really remove the terminals from the battery. Any battery u use will drain with that kinda non usage.

There are systems in ur bike that still requires some low amounts of power when the bike is off...like ur clock..internal memory for ur settings, mileage etc..

This is same for any vehicle...starting the bike/car at least once a week for 5-10 mins is more than enough to keep the battery alive. Also helps to keep ur internals lubricated.

maybe install a battery cut off switch at a more convenient location. the constant draining of the battery like that and recharging it can also reduce lifespan significantly