Can anyone please explain what s the relationship between the battery discharge rate C and the ESC rating.
I read that if a battery rating is 2200mAh 20 c 3s then the current drawn from it would be 2.2*20 = 44Amps.
So my doubt here is should i use an ESC which is more than 44amps ?

hello fellow
this may be useful

Since many years hobbyist have been demanding  for batteries with good capacities and more to it with huge discharge rates.  

Traditional  AA , AAA  and batteries  with other form factors can provide user a max current discharge capability of 1C  ( NIMH category ) . some Li-ion batteries can provide upto 2C max.

Demand for huge current discharge rates  leaded to research and outcome was Lithium polymer batteries ( Li Po )
Demand was mainly  by hobbyists  followed by specific industries. Often RC hobbyist need to rum motors for airplanes and race cars that requires huge currents.
These batteries are extremely good in providing huge discharge rates upto 20-30C nominally. Recent advancements leaded to discharge rates of upto 80-100C.
Means say u have 2200mah pack and 20C rating with it. It can give u discharge currents upto 2..2 x 20 =  44 amperes

These batteries need extreme care in handling. LiPo batteries must be charged very carefully.  Refer  materials  before moving with charging process. Charging of these batteries needs special chargers (balanced chargers).



What u mean by C rating ..
Say u have 2200 mah li-ion battery with u. it can offer u max 2.2 A/h discharge rate also known as  1C discharge rate .
lipos are specially made for huge discharge C ratings


its a blind rule ..... if ur ESC handles max 30 amps .. discharge rate of battery shd be more than 30 amps.. more amps much higher is safety ...
if u prefer a lipo with max discharge of 30 amps ..then under running  conditions lipo will get heated and may under pressure burst ...

best thing to do is .. if u have 2200mh lipo and 30amp ESC .. prefer lipo 2200mah with minimum discharge rate of 20C ..

make note : always use nominal rate for your calculations and not burst rate ...  overuse of lipo at burst rates may cause lipo bursts ...

Bhavesh, you are forgetting an important component: MOTOR.

Motor, ESC and LiPo are all inter-related.

Both ESC and LiPo specifications are directly related to the max amount of current a motor pulls. So the mAh and C ratings of the battery are to be chosen according to the maximum motor current draw.
The ESC just controls the amount of power going to the motor.

Swapnil is right its motor which will eat loads of current and ESC will only control it LIPO is supplier..

Just an example. You have a motor that can draw maximum 10A and you are using 4 motors for quadcopter. And battery that you have i.e. 2200mAh 3S 20C.
2200mAh = 2.2Ah
2.2Ah x 20C = 44A at particular time.
Means your battery can push maximum 44A. And other your whole setup electronics etc can safely pull 44A maximum. They can pull some more above 44A for some seconds which is called BURST RATE.
You have 4 motors so
4x10A= 40A
So you are IN

offcourse its a chain systems...
i have assumed.. ESC is chosen according to motor ratings ..
anyways .. its good to highlight....

Good day..

Quote from: Dharmik on March 20, 2012, 04:16:37 PM
So you are IN

Barely! The 3rd umpire may well have to be called upon.

In Electrical Engineering, there is some slogans, like
Electricity is a good servent, but good masters also.
Load is the king. etc. etc.

Now,
As load is the king,
Always calculate from Load.
Motor current(Maximum) = Motor KV corresponding to Prop & Watt/Current & Cell pack voltage.
ESC Current Capacity (Minimum) = Motor current x (1.4-1.5)
Battery Discharge Current Capacity = 1.2 x Batt AH x Batt C

PLEASE, keep in mind that only a wrong prop can damage entire motor, ESC and battery too by loading higher.

Thanks