Ok, so I got to thinking. My 510 is not a Titan and came with 2 manual batts. So I dont have to worry about the liquid going into the batts. I know its safe to drip with a 901 but what about laying it on its side for a while or if it got flipped led side down in my pocket? Could this cause damage? If so is there a way to plug the batt hole without affecting proformance?
I think you'll find that hole in the battery is necessary to allow a pressure differential between the outside air and the atomiser-side of the battery chamber as that's what activates the switch.
If you plug that hole, you may find that the battery will activate when the weather changes and not when you draw on the cig.