The battery cap was "extremely" tight when I took it off and when I replaced it with a new battery. The second optic seemed to work okay but I'm trying these out for USPSA matches and don't want any failures. I appreciate the comments. Hopefully the third optic works because I really like this optic. I run Trijicon RMR type 2's, DPP Pros, Sig Romeo 1 Pros. This optic gives me the best field of view. I want it to work.