I was just taking some measurements on the AA cells diameter.
Those industrial AA cells ( cells that are without brand, normally GREEN in color ) , used inside the original battery pack , are with diameter 14.00mm . The Sanyo 2700mAh cells are diameter 14.20mm .
There is a 0.2mm difference in diameter. And hence after assembly, the pack will indeed be thicker than before. Furthermore, I have used those transparent tapes to secure the cells together, they too will contribute to the extra thickness of the pack.
:think: In order to get a nice clean fit , I think we have to remove some plastic thickness on some location of the battery casing . Perhaps a small grinder can do the job nicely.
If I am able to do re-work on my battery pack , I will post more pictures here. :thumbsup: