Yes, yet I have a L0D with "10440 compatable" on the packaging.
Considering that my light is frequently used in proximity to my face, any mishap, would not be good. I would NEVER try a 10440 in a E01
I would also say running 10440 on low/medium means longer run time than an alkaline.
He was talking about the LD01-SS, which has a much lower headsinking ability.
