For MC-E in 4S using a BB 500, it looks like the board has to deliver ~6.6W of power (assuming Vf~3.3V at 500ma). The question is if the board can handle this without heat sinking. If you used a BB 400 (416ma nominal), then the board generates ~5.4W (assuming Vf~3.25V at 416ma). This is still higher than the ~3-4 watts of power that Wayne mentions earlier (presumably this figure of merit is without heat sinking).
For comparison, my SOB 1000 board seems to run very cool when driving a single Seoul P4 U2-bin, but the power level is probably comfortably within the ~3-4W range. What happens if you bump up the power by ~3W (roughly double the power), which is the case for a BB 500 driving an MC-E in 4S?
For 2S2P using an SOB 1000, I think the same power issue arises. If the SOB 1000 can run at ~6.6W power without heat sinking, then life is easy. Otherwise, you'd have to figure out some sort of heat sinking solution. Or drop down to an SOB 750 or similar current output. The SOB 750 would run at ~4.8W, assuming a Vf~3.2V at 375ma.
If you are going to install the components in something that has more space than an Aleph LE, maybe you can wire two boards in parallel? That means that you'd tie LED+ from the two boards together and similarly LED- from the two boards, and then feed the combined LED+ and LED- leads to the MC-E. You also have to connect ground for board 1 to ground for board 2, and Vin for board 1 to Vin for board 2. See this
link for some excellent photos of an example of two SOBs in parallel.
So for the 2S2P case, as an example, you could use two SOB 500 boards, each running at ~3.3W, instead of one SOB 1000.
I've tried searching, but it seems like alot of people are either using non-shoppe converters or more than 1 li-ion cell. I'm determined to try out my new MC-E led with a shop converter in a 1x123 rechargeable (either li-ion or IMR depending on current draw) format in my aleph light:devil:.
