I was considering running the new Energizer 2500mah NiMH AA Cells in place of the Sub C cells to power the main engine (Not the receiver and servos) in a 14-16 Cell configuration.

Advantages are weight savings and lower cost. Are there any disadvantages? Can they discharge at the same amperage as a same-voltage Sub-C Pack? Is anyone using them in a high power/high draw application?

Probably will not work as the AA (don't quote me) will only handle less than 10 amps discharge. sub c's will spike over 100 amps ok.

You can probably use them in application where it takes about 30 minutes to discharge, any faster and they will not hold up. Again don't quote my exact figures, but they are for radio and low draw applications.

Great idea though, I had the same idea.for the same reasons as you, low cost and pow wheight, the sapacity is almost the same as sub c. If we can increase the voltage by using more cells, then cut the amps down it will be better, but then we are dealing with more weight again.

Another idea is there are in-between cells that will deliver 30-50 amps . They are either 1100-1200 or 2000 nimh cells and may be called 2/3 A ? I'm not real sure they are popular with airplane doods.

Lipos are the answer although they are not cheap but you save a ton of weight.

Actually this is not always true. For slow boats and sport use they will weight less, but for high speeds and racing the weights are about the same - in some cases they are even heavier than similar voltage NiHM cells. The problem is, if you want to pull 80 amps for high speeds you'll need to get high capacity cells and run them in parallel, adding weight but not voltage. It all has to do with the power output you need.

Some AA NiHM cells can safely discharge at 50 amps - I watched Ed Hughey set a SAW record last Spring with eight of the red GP2000 cells. But most AA sized cells are limited to 10-15 amps max without damage. Not all sub-C cells will put out 100 amps, but the best quality ones can beat that. I don't know about the Energizer cells, but I assume that they are low-power cells and would be markedly slower than decent sub-Cs. You get what you pay for....[&o]