so I got the final results of MED mode of this light.

Battery started at 4.22v
2 hours @ 3.87v
3 hours @ 3.82v
3.5hours @3.79v
4 hours @3.76v
4.5 hours @3.75v
5 hours @ 3.74v
5.5 hours @ 3.72v
6 hours @ 3.70v
6.5 hours @ 3.67v
7 hours @ 3.35v and was a little bit dimmer. And could go longer..

I'm waiting for the batteries to charge up and try the strobe soon using this same test method.