You have to be a bit careful shrinking spring loaded battery holders like that. By pulling the sides in you can negate the spring action as they now grip the battery with the added side pressure.
The cell's I used were a real pain in a *** to get in and out at the best of time due to the spring tension, so I dont think they should be a problem. But I will take a closer look some time just in case.
The 6xAA holders came from here just in case anyone was interested.
