I've had my XC1 on a Glock 19 since June 2016. My 19 is my CCW and I went to do a little dry practice in the dark and my light wouldn't turn on. I tried for a few minutes to get it to light up using both the paddles and the constant on switch with no luck. So I turned the pistol over and smacked the slide on my palm a couple times and the light turned on... I turned the light on to constant on and smacked the bottom of the light on my palm and it turned off (constant on switch still in on position). I changed the battery and now it's working normally... is it normal for a quality light like Surefire to behave this way with a low battery? This is my first Surefire product so I don't have any experience with how they run on a low charge...