I have had one of these for a while now. I too run it using a single lipo, charging between runs (lets you test your batteries as part of your powertrain). Simply running back-to-back testing using two identical batteries will tell you what power loss you (if any) you are seeing with your batteries - if the power and torque numbers increase significantly using parallel batteries, then maybe its time to upgrade.

You would need a stout power supply to feed the main input - I have seen spikes of 80+ amps only testing 17.5's.

The unit provides some useful data, but I have found that same-motor testing for repeatability yields a variance on the order of 2%.

The dyno has the ability to run brushed motors off the internal esc - I have only used this with silvercans and Tamiya sport tuned motors. Based on the current spike, I would be hesitant to run anything faster than a 27t open endbell motor.

Using the external ESC option takes a minute to figure out - you need to manually test the esc without the flywheel attached, starting by adjusting the pulse width (in milliseconds) so that the esc initializes at the neutral point and then step up the pulse width to find the point where max throttle is achieved. Then you save the settings. This process should be re-done each time you test a different esc. I have found that the high point being set too high for a different esc resulted in the unit not running a motor test.

I have an RC Crewchief license and so I make motor models for my personal use, however this requires curve fitting data so the motor models created are only approximations of the data recorded by the dyno.

Comparing data directly in MSExcel is the best method to avoid approximation, however this method is not without challenges.

In the end, the results of this unit closely approximates the flywheel dyno I built previously, which uses a computer-based DAQ card to process input data at a much higher frequency. If you have a motor that is putting out about 5% less power and torque, as calculated from the machine, I would call that a significant difference.