oldfart
Elite Veteran
Location: Vancouver, Canada
My Posts This: Topic Forum | My voltage figures are based on the Eagle Tree computer readings we took a number of years ago, when we first started testing different battery combinations for use on the Swift, while geared for 1800 or more rotor speeds.
We also discovered during those tests, that the relative load, on any battery pack, was much more related to rotor speeds then to most any other factors. It was surprising to see the difference in wattage required to turn the same rotor at 1500, compared to that required for turning it at 2100 (from 425 watts to 825 in the hover if memory serves).
We also found that some batteries, with C ratings that were supposed to be high enough for the amprage demands of flying these size of helis, dropped substantially in voltage in flight, compared to some of their competitors. But non of the 3.7V lipos tested dropped anywhere near as much from their nominal voltage ratings as did the 3.3V A123's.
Of interest to some, is that recent testing we have done on some of the current versions of the lipo technology, actually show they delivered more then the nominal 3.7V/cell under 3D flight loads and rotor speeds!!
The next interesting finding, was the difference in the wattage requuirement to hover using different blades.
My conclusions from all these tests were that the A123's were fine under loading that were in keeping with what they were designed for - for use under relative lower current demands. But for the higher current demands and weight considerations of the more demanding area of 3D, where a high power to weight requirement is much preferred, they where not our favorite choice. |
