Figuring amp draw

[dizzymarkus]

Is there a forumla to get an approx: amp I should be drawing? -- I have a Watts up meter but thats only good for 50a con to 100a bursts-- Im over that for sure lol. I have a 89" plank running 12s 5000 with a Rimfire 50cc BL motor (230kv) and a 22 x 10 wood prop. Also does anyone know of a wattsmeter type device that will meausre or how to mechanicaly measure the actual amps in the running system like the watts meter?

thank you,
Markus

[Kington99]

yes, use this online calculator: http://www.ecalc.ch/motorcalc_e.htm?ecalc

any watt metre willl also tell you current draw, and if it doesn't use this formula

current = power / voltage

to convert the power reading to current

[Skiddz]

MotorCalc is good to use to get pretty close to actual draw, but something like an EagleTree logger will tell you exactly what your're pulling....