i,ll admit i don,t leave my eotech on 24-7, but i hunt turkey,s and it is on the whole time while i,m humting. i use plain AA batteries that cost 10.00 for sixteen batteries at walmart. i think i have about 100-150 hours on this set of AA,s, trying the eotech at trap,five stand and useing it to find the right load and choke for my gun,plus the turkey hunting and the batteries are still ok. at that cost it works out to .62 cents per battery. i don,t even use the best batteries advailable,but the cheapies. i might be concerned if it was on a fighting or self defence gun. i wanted a sight that would take the recoil and work,and that it does. eastbank.