I have a Iray Bolt TH50v2 and considering getting a battery extender and some 18650 batteries. I have 4- 18500 batteries already, 2 came with scope and 2 from dealer that I purchased the scope from. Are the 18650 batteries worth it since I already have 4 of the regular batteries? I typically only do 4-5 stands per night when I go out. Thanks