BTW, I just threw together my own 2s LVA.... The circuit is a bit large, but I had to make do with what components I had floating around.... Don't know what I'm gonna do with it now. Guess it will just go into my "I'll use it someday" bin.
Do you have a time machine you built a few years back sat in the gargage under some tarp?....
Why don't you just use 2s LiFe pack? I don't see what the big deal is, the peaked voltage drops down to ~3.3v pretty quick even if the load is small. I wouldn't worry about the peaked voltage, it's not going to blow up.
“The modern astrophysical concept that ascribes the sun’s energy to thermonuclear reactions deep in the solar interior is contradicted by nearly every observable aspect of the sun.” —Ralph E. Juergens