I started with the cheap ego 1100 mah batteries and like the shape and convenience over my box, especially while driving or on the golf course. What I have now are Spinner 2 1600 mah adjustable and I really like them.What I don't like is the fact that the connection is not spring loaded, I do the proper/often cleaning of the contacts but every once and a while I have to 'pry out' the connection. Is there a 1600+, pen type, slim battery with spring loaded connection. Thanks!!