I grabbed this plot off the KOKAM USA site (added later--did I forget to attach it??, here it is ). I thought it might be interesting for people. As I look at I am trying to understand some of the significance! It is a plot of the battery output voltage as a function of used capacity. Several traces are shown for different discharge rates (up to 20C). I note this is for a 4800mAh 20C KOKAM single cell lipo. I think they call this an "ultra power" cell design. It looks very similar (maybe a bit higher capacity) to what a lot of people are using in their multi cell packs.

One other point is they say the temperature is 23^oC. I am not sure if that is room temperature or battery temperature. If it is battery temperature, then they must be providing a fair amount of cooling! From the 20C trace, the power dissipated in the battery is (estimated at 2Ahr point by the (voltage at 1C-voltage at 20 C)*96A~31 watts! Note again this is a single cell. Also this is energy not going into your prop! I note from the AXI 2826/10 spec, maximum efficiency of the motor is between 20-30 amps. This would be equivalent to a 4C to 6C discharge rate for this battery. Since I don't have an AXI motor, I am not sure how people are propping them But it would seem reasonable to prop them somewhere in this range for level flight. I will say I have only flown electric RC (not CL yet) with brushless motors and Lipo batteries, so I could be all wet here.

One obvious thing, if you are aware of your average discharge rate during a flight (10C for example), then you can see how much the voltage drops vs used capacity. If you have a time with throttle control, you could set the throttle to allow some headroom for ramping it up (using the JMP-2 timer) or for the level in governor mode. As I said, I am not positive how to use it yet.

As best I can tell, most folks running the AXI2826/10 are using 4 cells and running approx. 35 amps.  That produces around 500 watts and uses up around 2500-3000 mah.  From all reports that gives a very tractable setup that doesn't overstress the motor or the batteries.  Some of the RC'ers I've read about are running the batteries so hard they last for only 10 or so runs.  The little documented testing I've seen shows that keeping the total draw from the battery to around 75% of capacity and keeping the max current down in the 10c range should give upwards of 200+ runs before the battery loses more than 20% of its capacity.

There are some real kickers in the motor efficiency and battery internal resistance.  Those factors are a big difference between a good setup and something marginal.  Kind of like the difference between a Fox 35 and an OS 35.  Picking a motor with 80% efficiency instead of 90% and a battery with 20% higher impedance will put a big knock on the overall performance.  All the wasted energy gets dumped into the battery and motor as heat.

Mike,
You certainly know more about the relative qualities of the different manufacturers. In this case I googled KOKAM and found this information. I am not sure where to look for other manufacturers. Most of the brand names seem to be repackaged cells from the actual cell manufacturer, and I haven't found much information. Maybe I haven't looked hard enough. I was just curious how the voltage varied over the capacity. Also capacity really means you can suck that much charge out. Maybe in KOKAM's case they need to go to 2.7V to get that much charge.