First flight results with the new SLS SPEED compared with the SLS APL serie

After the 3 hoover flights it was time to try out the flight field and test the power of the new lipo’s. No settings have been changed, same RPM of the rotor head and I was going to try some speed flights and some soft-3D flying. The results compared to the 3 year old SLS APL:

Of course there is a big difference in performance. Where the old APL’s have large voltage drops to 3.2 Volt the new SPEED drop to 3.78 Volt at 150 Amp. Noticeable is the head speed and sound of the rotor blades which are sort of  a harmonic sound where the APL drop in RPM and speedup the head speed short afterwards.


The 3 years old APL batteries. blue = RPM, orange = voltage, red = current.
The new SPEED batteries. blue = RPM, orange = voltage, red = current.








By taking a closer look, at the first part of the graph where I performed some pure speed flights and in the lower (second part) some soft 3D flying.

Speed flight with the SLS SPEED batteries, the handle the 120 – 150 Amp peak much easier hand a low voltage drop at the current peaks.

Speed flight with the SLS APL, show large voltage drops where current peaks of 120 Amp occur. Keeping in mind that this not a good reliable data and not every flight had the same pitch angle etc. Even more important, the APL are 3 years old and are 40C lipo cells where the SPEED lipo’s are 70C cells. But for me one thing is clear:

  • APL cells are still perfect lipo’s for normal 3D flying, they perform well and have limited voltage drops to 3.5Volt / cell
  • The SPEED lipo’s will never perform at their limit therefore, my assumption is that because of the harmless use they should live longer.

More data, logging and flight experience will follow. This is when I will increase the rotor head RPM and increase the pitch angle. The speed governor can take 200 Amp continuously, and 400 Amp peak. So let’s have some more fun!




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