Just picked up my Colt/Aimpoint to check battery, I've had the PRO since 3/1/21 and with the lowest setting that I would use the battery was almost dead at 5,000+- hours. For those of you that own PRO's what's the best battery to buy and I'd like to know how many settings you have? Aimpoint says one thing and I am coming up with something else.Thanks!