I use the 8AX Commander for duty and have had no problems with mine. I use both batteries and neither one has given me any problems. How old are your batteries and how much use do they receive per day? It might just be time to replace them if they're pushing a year. I use my batteries close to 6 days per week and I work 2300 - 0700 hrs, so basically my entire shift is in low light conditions. Surefires' customer service is second to none. Shortly after I got my 8AX Commander, about two months, my bulb went out. I contacted customer service at Surefire and they mailed me a new bulb for free (about a $30 savings). I use several other Surefire products for duty such as the X200B, M2 combat light, and M952XM07 on my carbine. I trust my life with these lights and believe that they are the best light made. Paul