Wow Matt, thanks a bunch... more in one post than I got out 100's I've read.

Well, it's no wonder I was so mystified by all the hazy information I was gathering. I assumed this was a science, not hit-and-miss try-it-till-it-works kinda thing. I'm an engineer, so I am perplexed by the lack of collective mathematical precision all this should boil down to. Why is it not quantitative in some analytical way? I don't get it.

In the glow world, we start with a prop turning at a specific rpm to give a fairly well defined thrust... that in-turn yields a horsepower requirement, then you select the engine to provide that rating... done. Seems the same routine should work for electrics?! There are 746 Watts per Horsepower... so you rate them by watts, but it's still power.

So, help me to understand... why can't I use my existing batteries? They are all 3S 11.1V lipos... so don't they just limit flying time by being too small? Or, do these types of batteries somehow deliver whatever the motor/esc wants and that in-turn overloads them?

Thanks again for your help!

A humble student [8D] of a new art...