Originally Posted by dude_109
Stock fan+motor on 4S only pulls 25amp or so if I recall so 30A is sufficient but 40A is safer and will stay cooler. All of my in this series are on 30A and I fly with 3S and 4S.
You just saved me from buying a new ESC....i got a 40A i need for another ship in mind.....however i got several 30amp esc's. But Ill probably hook up a external BEC to be safe....though still be running a bit hot.
I seen these things at my local field "Baylands" some of the good men there look like they are having heaps of fun with these things...