Need Reliable 4 volt panel

[fireofenergy]

Hi, I need only 4v because the LiFePO4 battery is max at such, and the leds only need 3v - 3.2v. This gives a little room for AMC drivers (for sell on deal extreme and are touted as the best there). I don't want to go 12v (and 3 or 4 x everything else).

I just want to make a single Cree XML light, powered by a single Headway LiFePO4 (or similar), charged by just 4 or 4.5V. I believe this would be the most efficient approach to most ALL lighting...

I also periodically read posts here... and came to the conclusion NOT to try to build my own
But I can't even imagine a remote possibility of finding a decent size four volt panel past those little 100mA plastic thingy's on ebay.

I could buy (multiples of eight) some of those more expensive 6x6 cells from an ebayer with good ratings, getting plexi, some good "rubber seal" material (also about a 1/4" thick) and sandwiching it all together to make (possibly a fold-able) panel. It seems, with a good seal, and if the cells were free to move about only a 1/16th of an inch, thermal damage could be avoided (but then I wonder if the solder would come apart).
Nevertheless is there ANY way to buy such a panel made professionally without having to invest upfront thousands of dollars to a company that speaks Chinese?

[Mike90250]

There are now, many battery charger IC's that will do as you ask, they charge phones from 5V USB, and likely have enough range to manage solar PV fluctuations.

But you have to match/design the charger to the batteries, with all the feedback and controls, the batteries need. It can be very easy to overcharge LiFePO4 cells.

The solar power source is the easiest part.