Ok, so I'm a nu-bee at this and the learning curve seems to be kicking my ass.... Would appreciate any help available.
I've been trying to pick a couple of batteries to run in series for my Rascal 72'' weighing in around 8-9 Lbs flyable weight. (inc. batteries) I was given a somewhat large Himax outrunner motor (HC5030-390) which has a max power of 1500W, 12000 max RPM, kv=530, Rm= .031, Lo= 1.8 @ 10v. I'm using an 80 Amp burshless speed controller everything running through 12 gage wire and banks fittings. I'm looking at placing two 4000mAh 4S 40c batteries in series to run the show.... I know the prop makes a difference bu tset that aside for the moment,
My question is: calculating 3.3 volts per cell (suggested by the motor's manual) X 8 cells (two in series) = 26.4 total volts which is right up this motors alley. But when I calculate the 4 amps X 40c I think I get the potential of a 160A burst discharge which is way over a motor saying it has an efficient operating current of 30-50A, 65A max for 15 sec.. So it seems to me if I open the throttle full on takeoff I'd be cramming (potentially) 160A into the motor... which I believe should turn things red hot in seconds. What am I missing here? Do I need to limit the throttle in my radio down to... what 35% to keep the Amps in the 65-70A range? Do I try to compensate with an oversize prop? I don't want to fry things but I don't have any experience with this and need a bit of advise.
Thanks in advance for your help.
drd
I've been trying to pick a couple of batteries to run in series for my Rascal 72'' weighing in around 8-9 Lbs flyable weight. (inc. batteries) I was given a somewhat large Himax outrunner motor (HC5030-390) which has a max power of 1500W, 12000 max RPM, kv=530, Rm= .031, Lo= 1.8 @ 10v. I'm using an 80 Amp burshless speed controller everything running through 12 gage wire and banks fittings. I'm looking at placing two 4000mAh 4S 40c batteries in series to run the show.... I know the prop makes a difference bu tset that aside for the moment,
My question is: calculating 3.3 volts per cell (suggested by the motor's manual) X 8 cells (two in series) = 26.4 total volts which is right up this motors alley. But when I calculate the 4 amps X 40c I think I get the potential of a 160A burst discharge which is way over a motor saying it has an efficient operating current of 30-50A, 65A max for 15 sec.. So it seems to me if I open the throttle full on takeoff I'd be cramming (potentially) 160A into the motor... which I believe should turn things red hot in seconds. What am I missing here? Do I need to limit the throttle in my radio down to... what 35% to keep the Amps in the 65-70A range? Do I try to compensate with an oversize prop? I don't want to fry things but I don't have any experience with this and need a bit of advise.
Thanks in advance for your help.
drd
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