I HAVE A PROMAX 400 7.4-8.4 MOTOR , A SIG ESC20 AMP ESC, AND A 11.1V 1900 mah Li-Poly BATTERY. WILL THESE ALL WORK TOGETHER? IF NOT WHICH WOULD BE THE MOST ECONOMICAL TO CHANGE. THIS IS IN A SIG RASCAL ELECTRIC. I STARTED OUT WITH THIS SAME MOTOR AND ESC WITH VARIOUS BATTERIES AND PROPS. THE NICAD's OF 6 & 7 CELL'S DID NOT GET IT OF THE GROUND NO METTER HOW MUCH GRASS OR ASPHALT RUNWAY IT HAD. THE Ni-MH's GOT IT UP BUT RAN OUT OF JUICE BEFORE I GOT MUCH ALITITUDE. SO SOMEONE SUGGESTED THIS AND AFTER THINKING ABOUT THE PAST AND LISTENING TO OTHER'S AND CONSIDERING MY BUDGET I SOLD AN ENGINE AND PURCHASED THIS BATTERY PACK FIGURING I COULD USE IT IN FUTURE FOAMIES IF IT DID NOT WORK OUT IN THE RASCAL. NOW YOU HAVE THE HISTORY. WILL IT WORK,WHAT DO I NEED? THANKS

It will work absolutely fine! BUT, you need some way to check the amp draw if you are using 3s to power a 400 motor. Start with a small prop and work your way up, because you will not want to be drawing more than about 8A-10A. If that is direct drive a 5" or 6" prop is about all it will cope with, but if it is geared then there are more possibilities.

Cheers, Phil

You're definitely headed in the right direction. Voltage is the electric equivalent of cubic inches.

Someone gave me a NIB Rascal with the Sig ESC20. There is nothing in the literature about low voltage cut off for this controller.
Does anyone know the scoop on this? I will run it on nicads at first, but will tinker with other technologies later on.
Thanks_bob

I have no other info on it, however I am running mine with a 3 cell (11.1volts) 1900 Li-Poly pack and have had no trouble at all(about15 flights now). Throttle management is key.

That sounds good! This may sound dumb, but the prop adapter I got with the kit doesn't fit the APC prop recommended. What am I doing wrong? What prop are you using on the 11.1v set up? I assume you are still using the stock motor_bob

you need to use one of the collars that came with your prop. APC has about six of them with the prop. By the way the best prop I found for it is 8x6E.
Kevin