How about using two CR2 instead of CR123A powering a E-series KL1 or E2e bezels? The catch would be to make those 2xCR2 bodies, which would be shorter that the E2s. Is this project worth the effort at all?
I'm trying out a new one using Duracell 28L 6v batteries. Two in series is the same length as 1 AA battery, for 12v. These are the lithium version of the L544 (5xLR44)batteries.