Brushless and ESC calculation
 

How do you calculate the combination to figure out what Battery size in C you need ?

Thanks

RE: Brushless and ESC calculation
 

basically what you have to do is figure out what the max cont amp draw is for the motor, then for extra room to make sure things don't run hot divide that number by 80%, then to size your battery divide that second # by 80%

so here is an example, say your heli takes 6 amps cont all full pitch and throttle, 6 / 0.8 = 7.5 amps which is the max you should see unless your motor stalls (in this case you would want a 20 to 25 amp ESC, or one with current limiting), then take 7.5 / 0.8 = 9.375 amps is what your battery needs to be rated at continuous

so say you wanted a 1000mAh pack, take 9375mA / 1000mAh = 9.375C and because they don't make a pack like that, you would just want to get a 10C pack

If you wanted a 1200mAh pack, then you could go with 9375 / 1200 = 7.81C or you could go with an 8C 1200mAh pack.

RE: Brushless and ESC calculation
 

but how do I figure out the max current draw of a motor? they rate them as 38ooKv

RE: Brushless and ESC calculation
 

well it depends on the motor, but the mfg should tell you how many watts and amps it is rated at. There should be a max cont max burst ect. I am guessing you are talking about the esky motor?

For that one you will want to go with probably a 25A esc, although you might get by with a 20A esc.

The battery you are going to want for that is probably atleast 1300mAh or so and 10C or better, with a total cont output of like 12A or better.

RE: Brushless and ESC calculation
 

Here is the data: http://www.twf-sz.com/english/products.asp?prodid=0145
MAX amps is 20 as per E-Sky.