I have a Lavatube clone with Trustfire 18650 3000 MAH batteries which have the nipple so the battery does not exactly fit. I have been using it that way for 2 months. People talk about putting O-Rings on the bottom to hide the threads. Do I really need that or is it just for appearence? Are my Trustfire batteries safe with this Lavatube or do I really need to sink more money into batteries that fit without the nipple?