The issue with the threads is not how secure they are but how conductive they are. I've got a Z-max V3 Telescope that I resently had trouble with, and in fact returned for replacement to the B&M I bought from (wrongfully as it turns out). Mine began failing to display anything while the Z-max was working fine. The only to get the display to work again was to remove and reinstall the battery. After I had replaced the Z-max I posted an article detailing what had happened. Then I got the story on Noalox. Been using it ever since without problems. Apply a coating on the male threads then with a tissue wipe it away leaving Noalox in the area between each thread.
Note also that when telescoping the tube leave approx 1/8 in of the battery extending beyond the end of the tube, then install the battery cap. This should keep you from overtightening the battery.