That particular lock is the worst part of the whole bike. Mine snapped while riding during my first season. Weak metal plus vibration plus air pressure inside the box makes bad lock juju.I was visiting one dealer the other day who was putting some sort of silicon compound onto the locks on the bikes in his inventory, so that if (when) they break, the pieces will remain attached and not end up inside the engine. Simple but elegant preventative fix. Although that lock is tight and a monumental pain in the butt, resist the temptation to loosen it. The tighter it is, the longer it will last.
FYI dont force the battery lock.. make sure its aligned and turn. I hear they like to break.