You can get up to 1250 hours run time (33% lighter than alkaline batteries) with the AA models eotech 552 and 512 with the AA lithium batteries. These batteries sell at department stores for $12-$18 a pair.

Eotech Has introduced a brighter and sharper reticle to all Eotech holographic weapon sites Also, these changes included an extension of 2 times the battery life at the brighter levels, yielding a total of 200 hrs continuous runtime in the 511 and 551 and 630 hrs continuous in the 512 and 552. If lithium AA batteries there was also the elimination of the one-second delay in the scrolling feature when changing the sight's brightness. These changes are all collectively known as Revision Level F. This has been noted on the outside of the protective hood with the capital letter "F". All models produced since the beginning of Feb of this year is this new Rev level. The previous Rev E level is no longer produced. This revision level applies to all models.