Even though the mil recticle in the Delta Stryker 1-6x scope is prominent without illumination, I wondered how long the red dot illumination would be "daylight bright" since it is so bright on max illumination with a fresh battery.
I put a new Sony CR2032 in the scope to see how long the very bright illumination would last with the scope left on in the maximum illumination setting of 11.
Delta Stryker 1-6x Illumination Test
Day 0 - Start, red dot brightness = Aimpoint M3 max setting bright
14 hrs - slightly less bright than when started, but not a whole M3 click less than max bright though
21 hrs - 1 click off max M3 brightness
24 hrs - 1 click off max M3 brightness
Day 2 - 1 click off max M3 brightness
Day 3 - 1 click off max M3 brightness
Day 5 - less bright than 1 click off max M3 brightness, brighter than 2 clicks, about setting 9 out of 12 on an Aimpoint T1
Day 7 - about 2 clicks off max brightness M3, 8/12 T1
Day 9 - about 2 clicks off max brightness M3, 8/12 T1
Day 11 - about 2 clicks off max brightness M3, 8/12 T1
Day 14 - about 3 clicks off max brightness M3, 7/12 T1. IMHO at this point the illumination is not really visible in sunny, daylight conditions
Day 18 - about 3 clicks off max brightness M3, 7/12 T1. Test terminated.
So based on this one unscientific test, it looks like my example of the Delta Stryker 1-6x scope will remain visible in daylight conditions for less than 2 weeks if the illumination remains on in the max setting of 11.