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Can you help plz

#1
Im new to building flight.so I don't understand how to pick the batteries. Batteries had 3 classifications like mah,c ratings, cells.
So i pick the Emax mt 2213 brushless motor with 1045 propeller,
and also picked the BLHeli 30A 4S ESC F16740,
Now I want to get battery.
I have 2s 800mah 20C battery.
Is this battery fit with that ESC n motor or can you guys teach me to how to picking method.
 

jaredstrees

Well-known member
#2
MAH is basically the amount of energy the battery can hold. The larger the number the more capacity it has. Usually it equates to longer run times.

C rating is how much the battery can discharge. The higher the number the more "juice" the battery can deliver at once.

Cell is how many cell the battery has. 2s is a 2 cell battery. The ESC you have is rated for up to 4 cells (4S). The higher the number of cells the more voltage the battery has. 2 cell is 7.4v, 3c is 11.1v, etc. each additional cell adds about 3.7v. The more cells you have equates to more power. A plane that can fly at a certain speed on a 2 cell will be faster on a 3 cell.

Your ESC will support up to a 4 cell battery, but it is more important to match the battery to the aircraft. If you are building a might mini, you have a decent battery already. A 4 cell would most likely be overkill and not fit well or be too heavy.

This is all a bit generalized, but hope it helps!
 

JimCR120

Got Lobstah?
Site Moderator
#3
kn,
The LiPo you've picked can work but you should consider the platform too. Lower capacities (mAh) equate to lower endurance but also lower LiPo weight. Here you'll have to determine which is a better for your airframe and for what you want to do.

Do you have a particular aircraft or at least aircraft style you are thinking about?

Welcome to the forum.
—Jim
 
#5
Im looking for FT mini Sparrow from flitetest free plan.I got the answer.thnx
Bt I wanna know to ESC or motor have the C ratings limits?
If I get 1000mah 3s 60C or 70C battery, is it damage my ESC or motor?
Also thanks a lot jaredstreet,jimCR 120 and @balu.
 

earthsciteach

Moderator
Moderator
#6
You don't have to worry about C ratings being "too much" for an esc. The motor pulls the current it needs and the esc is matched to the motor.
 

Ricci

Posted a thousand or more times
#9
Well in my opinion 2 cell and 800mah are to small for the 2213 motor. I suggest a 3s the capacity depends on the size of the aircraft.
 
#11
Thnx a lot

MAH is basically the amount
of energy the battery can hold. The larger the number the more capacity it has. Usually it equates to longer run times.

C rating is how much the battery can discharge. The higher the number the more "juice" the battery can deliver at once.

Cell is how many cell the battery has. 2s is a 2 cell battery. The ESC you have is rated for up to 4 cells (4S). The higher the number of cells the more voltage the battery has. 2 cell is 7.4v, 3c is 11.1v, etc. each additional cell adds about 3.7v. The more cells you have equates to more power. A plane that can fly at a certain speed on a 2 cell will be faster on a 3 cell.

Your ESC will support up to a 4 cell battery, but it is more important to match the battery to the aircraft. If you are building a might mini, you have a decent battery already. A 4 cell would most likely be overkill and not fit well or be too heavy.

This is all a bit generalized, but hope it helps!
 
#12
Im new to building flight.so I don't understand how to pick the batteries. Batteries had 3 classifications like mah,c ratings, cells.
So i pick the Emax mt 2213 brushless motor with 1045 propeller,
and also picked the BLHeli 30A 4S ESC F16740,
Now I want to get battery.
I have 2s 800mah 20C battery.
Is this battery fit with that ESC n motor or can you guys teach me to how to picking method.
Hi, do you know 30a ESCS are compatible with 400-450mm quadcoper FPV ? and what size FPV do you want to build? I recommened a article to you "Quadcopter frame and lipo battery and motor and propeller size matching table" http://www.rcdronegood.com/quadcopter-frame-lipo-battery-motor-propeller-size-matching-table/ , it can help you to solve this question.
 
#13
mAh is a bit misleading when it comes to capacity. mAh is measured per cell. This means a 3s 1000mAh battery has exactly half the capacity of a 6s 1000mAh battery. A 3s 2000mAh has the same energy density as a 6s 1000mAh battery.

Volts x Amps = Watts

All this is to say that watt hours is the best way to tell overall energy density.

megabotz
 
#14
mAh is a bit misleading when it comes to capacity. mAh is measured per cell. This means a 3s 1000mAh battery has exactly half the capacity of a 6s 1000mAh battery. A 3s 2000mAh has the same energy density as a 6s 1000mAh battery.

Volts x Amps = Watts

All this is to say that watt hours is the best way to tell overall energy density.

megabotz
You are right, in addition, c-rating also should be consider, Discharge Rating = Ah x C-rating. battery c-racing is greater than target c-rating but not too higher.
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
#16
Other than it'll need to spin the other direction? Not much.

If your airframe has any right-thrust angle to reduce torque roll, you'll need to reverse that (needs to be left by about the same amount).

Also the prop-adaptor may slowly loosen over time, since the motor torque acts in reverse -- standard props torque in the tightening direction, making the adaptor tighter. If it starts out tight, it probably wont' loosen in a single flight, but it will eventually. check and tighten as a part of the pre-flight and you'll be fine.
 
#17
I can't figure how may I calculate motor A. I got thr motor n looking for how many A's can use that motor. bt didn't have anything about A. please help me to figure that.