so ive had my 100w for a few weeks now..been using some standard 10A batteries cause i dont go sub ohm..i recently bought some efest flat top 20a batteries..and while even though they dont APPEAR to be any bigger than my other batteries..even after holding them up together...the efest batteries seem to have a MUCH harder time getting them to go into my 100w..they almost DONT wanna go in...any clue what could be causing this? dont seem fatter..or longer