If you want a true measurement, use the voltage delivered to the motor while under load and multiply that by the current you measure. The voltage on some packs will drop below rated voltage during this test.
I'm not surprised that a sub-C pack outperformed a "AA" pack. They usually do.
Age verifier Northern Alberta
Democracy is two wolves and a sheep discussing what's for dinner.
Freedom is the wolves limping away while the sheep reloads.
Never confuse freedom with democracy.