I just noticed that betteryjunction is now offering the 3-mode R2 P60 light engine that runs up to 18v. So i got the idea of running a DBS with 4x18650 cells! I have done a runtime test on the DBS with 2x18650 XR-E R2 pill and got ~32000 Lux for ~3.5 hours. would that mean that i would get the same Lux but for 7 hours? I could get a really expensive wiffleball bat! lol