I have one as well. Its actually quite simple. I just got a "step up" adaptor and an optional "cell extender" from surefireparts on ebay, and it works great! Just like a C2, C3, G2, etc etc, depending on how many cells you have. Right now, i have a cell extender on the e1e, so its pretty much like the e2e, or G2, or C2, etc etc. But i have a e2e body coming in, and that will be like a C3, 9P, etc etc Check out the pics:
E1E with cell extender attached (from surefireparts as well)
stepup adaptor from surefireparts
all attached
p61 inside the step up adaptor
Requires some sort of bezel, G2, C2, Z2, your choice
I like this setup, becuase i can switch it quickly to a KL1
Hope this helps! No melting, or lack of run time required. It works exactly like a g2, or c3 (depedning on your body), at the size of a e-series!