DBono99

My Feedback: (1)

Hi All Would it be possible to get 500 watts using 3's??
That would be something like 10volts x 50 amps?
Thanks Dan

Walt Thyng

My Feedback: (9)

First off 3S = 4.2 X 3 which yields 12.6 volts. The next question is what is the discharge "C" of the pack. 500 watts would require amp amp draw of approximately 40. This is not an unreasonable draw on say a 20C 2000mah pack.

Rob2160

Yes, entirely possible. depending on battery capacity and C rating.

EG.. if you have 2000Mah batteries, for 50amps you will need around 25C - This means the battery can discharge itself in 2.4 minutes (60/25)

IE 2 amps in an hour (1C) or 50 amps for 2.4 minutes. (25C)

Realistically.. if using 2000mah batteries you would be better using higher C rated batteries eg 30C or 40C for this application..

if your batteries are 3S 5000Mah then 1C is 5 amps per hour.. or. 50 amps for 6 minutes.. (effectively only needing a 10C battery)

a 3S 5000Mah 30 C battery can give you 150amps. (1500watts)

What application are you considering?

Rob2160

PS.. its a pain not being able to edit posts at the moment...

My above examples are using 10 volts for a 3S battery purely to simplify the Math

As Walt Thyng correctly stated, a 3S battery is 12.6 V fully charged.. dropping to the 11s under load and mine end up around 11.3 volts after 5 minutes of flying with Helis.

So the numbers in my examples are very conservative and you will get better out of a real 3S battery.

DBono99

My Feedback: (1)

Hi All My batteries are all 25C 4000 .How long will the battery hold at 11? AT 11 with 45 amps I will be able to get 495 watts.. Should be good enough for my 4-5 lb Cloud Dancer 40.

Thanks Dan
PS I also have 5's 4000 25C. Might be a little to heavy.

Goldenduff

You have 4amp hours. You will be demanding 45amps. 4/45= 0.0888889 of an hour. Multiply 0.089 by 60mins and you 0.089 hours is 5.3minutes. 5.3 minutes is 5mins and 20sec.

Given that you cannot use 100% of a lipo or it will die (70% is acceptable).
Given that the closer the amp draw gets to the batteries max the less efficient it is (effectively the capacity is reduced if you use high amp draw).
Given that manufacturers are prone to exaggarating C ratings

I say you would be pushing it to get 4mins.......

Reducing the prop pitch and or diameter would reduce the current draw and extend times.....

All the best

DBono99

My Feedback: (1)

Hi All I was thinking of using this motor. Would have love to use 3025/06 but they are backoverd. You know what that means.
:http://www.allerc.com/hyperion-zs302...or-p-4596.html

Thanks Dan
PS Looks like I might have to go with4's..