replaced the shell on my controller and now it wont turn on

I replaced the shell on my controller because the rubber grip had come off. I replaced the shell, and after putting it back together and putting in new batteries it turned on fine, and worked perfectly. The next time I went to use it, the controller would not turn on, until I took the batteries out, and put them back in. Now I have to take the batteries out and put them back every time I want to use the controller.