Originally Posted by
bensid54
I just bought a Century Swift 550 size I'm running two 3 cell batteries in parallel and was wondering what the smallest mha size battery these things will run on? I'm presently running 2200mha 3 cell right now and I notice the higher the "C" rating the cooler the batteries are at the end of my flights.
Yes, in effect the C rating tells you how many amps a battery pack can deliver without running too hot. So the higher the C rating the more watts that pack can deliver before it gets overstressed (heats up).
You are trying to run it using 2 x 3S/2200 mah packs in PARALLEL, resulting in a battery pack of 11.1V/4400mah??? That would mean you are trying to set it up to run on 11.1 Volts??? That would not be able to deliver enough power to fly it very well if at all. It takes about 400 watts (volts x amps) to just fly a 550 sized heli in a very sedate way, with a rotor speed around 1500.
The max wattage a 20C pack can deliver for very short periods of time (a few seconds) is 11.1 x 4.4 x 20 = 976.8....over a period of a few minutes that would be about 20% of that....say 200 watts.
You would need to be using a motor with a KV of about 1500, just to get a 1500 head speed with a 10T pinion. And as you can see, your max wattage available would still be too little for any sustained flight of consequence.
Even running the packs in series (6S/2200) would allow you to use a motor with a more reasonable KV (e,g 800 to 1100), your flight times would only be about 2 1/12 minutes or maybe even less, depending on the quality and condition of the packs.