Batboard

Hey just picked up the first SL300 and got a question on the battery. It has the BT90 in it but everything says the BT100 is the right battery. Also I only see one battery door listed for these. So my question is if I get the bigger battery will this door work? Had a couple of SL7550's and loved them other then battery life. And I've not used this SL300 yet to see what battery life is like. Will I notice much of a difference if I do switch batteries? Thanks