Sizing the battery and servos for an RC airplane

by Andy

Hello,

How can I size the proper type of battery, per electric motor. I see a 24xRC 1700. What does that mean?

The proper speed controller per battery or is it per motor?

Size the proper servo with airplane

Any suggestions, would be greatly appreciate it.

Thank you
Andy

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Sizing the battery and servos for an RC airplane

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Not sure what 24xRC 1700 means...
by: Matt

Hi Andy,

Sorry it took so long to get back with you.

You want to size your battery according to the size of motor.

A motor will draw a certain amount of current so you want to make sure your battery's capacity will keep up. If the capacity of your battery is too small, it will ruin the battery.

The same with an ESC. You want to make sure your ESC is rated for the maximum current the motor will draw.

Do you have a particular motor in mind? Maybe I can help.

I am not really sure what 24xRC 1700 means.

A battery will be characterized as its nominal voltage, capacity, and C rating.

For example a 3S lipo pack will have a nominal voltage of 11.4 volts.

If that battery has a capacity of 2100mah and it rated for 10C discharge, you could run a motor that pulls a maximum of 10 x 2100mah, or 21 amps.

Reading the page below may help.
Reading this page about Lipo Packs will help you understand.

As far as sizing the servos, taking a look at the page about
RC servos should help answer your questions.

If you have more questions be sure ask,

ATI 4130/16
by: Andy

Hello Matt

The motor I have, is an ATI 4130/16 and not sure what type of ESC nor battery
to purchase. Everything I gather is from other peoples suggestions such as
get an ESC Turnigy 80 with a 4400 mAh Lipo battery.

For me, that's not enough. I want to be able to properly size everything,
from the prop and engine which i determined from the specs I got off the
engine. So now I need the proper battery and ESC.

I appreciate your time and assistance.
Andy

Did you mean AXI Gold 4130/16 Outrunner Motor?
by: Matt

Hi Andy,

Did you mean AXI Gold 4130/16 Outrunner Motor?

In any case, Here are the specs for the AXI 4130/16

I see what you mean now that it calls out a 24xRC 1700 battery.

I think the 24 means it needs 24 Nicad cells, Which would be 1.2v x 24 = 28.8 volts.

But I image you'll be using Lipo packs since Nicads are a becoming a thing of the past.

Above that it calls for a 6s or 8s lipo pack. An 8s lipo pack would be 3.7 x 8 = 29.6 volts

I am going to go out on a limb here and guess that the 1700 means you need a capacity of 1700 mah? But that doesn't really jive with the rest of the picture here...

I am not sure what it means by 60A/60s. That confuses me a bit. If anyone knows please enlighten me! lol

But it calls out a 77Amp ESC, so we can be fairly confident that the max current draw for this motor should not exceed 77Amps with the propeller and weights called out in that chart.

If I understand it correctly, it calls for anywhere between a 6S and 8s Lipo back with a maximum discharge rate of 77 Amps.

A 30C 21000mah lip pack would have a max discharge of 63 Amps

A 40 C 1700mah lipo pack would have a max discharge of 68 Amps

A 40 C 2100mah lipo pack would have a max discharge of 84 Amps

The number of cells, whether you go with a 6s or 8s would be determined by the weight of the airplane, the type of airplane, and the propeller size.

I guess you can experiment. More cells is more power, but adds weight.

What kind of plane do you have? What's the weight?

Try this Axi motor calculator tool out. It may shed some light on the situation.

I am curious as to what the 60A/60s means, because on other motors on that page I see 60A/20S. That is really the only part I'm not sure about. Maybe someone else will chime in here...

But I think you will be safe sizing it for a max of 77 Amps.

To be completely comfortable, it wouldn't hurt email AXI and see what they say: info@modelmotors.cz

I hope this helps. Keep me updated on what you choose if you don't mind,

Matt

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Hi Andy, Did you mean <b>AXI</b> Gold 4130/16 Outrunner Motor? In any case, <a href="http://www.modelmotors.cz/index.php?page=61&product=4130&serie=16&line=GOLD" rel="nofollow" target="_blank">Here are the specs for the AXI 4130/16</a> I see what you mean now that it calls out a 24xRC 1700 battery. I think the 24 means it needs 24 Nicad cells, Which would be 1.2v x 24 = 28.8 volts. But I image you'll be using Lipo packs since Nicads are a becoming a thing of the past. Above that it calls for a 6s or 8s lipo pack. An 8s lipo pack would be 3.7 x 8 = 29.6 volts I am going to go out on a limb here and guess that the 1700 means you need a capacity of 1700 mah? But that doesn't really jive with the rest of the picture here... I am not sure what it means by 60A/60s. That confuses me a bit. If anyone knows please enlighten me! lol But it calls out a 77Amp ESC, so we can be fairly confident that the max current draw for this motor should not exceed 77Amps with the propeller and weights called out in that chart. If I understand it correctly, it calls for anywhere between a 6S and 8s Lipo back with a maximum discharge rate of 77 Amps. A 30C 21000mah lip pack would have a max discharge of 63 Amps A 40 C 1700mah lipo pack would have a max discharge of 68 Amps A 40 C 2100mah lipo pack would have a max discharge of 84 Amps The number of cells, whether you go with a 6s or 8s would be determined by the weight of the airplane, the type of airplane, and the propeller size. I guess you can experiment. More cells is more power, but adds weight. What kind of plane do you have? What's the weight? <a href="http://www.modelmotors.cz/axisetupeflighteng/" target="_blank" rel="nofollow">Try this Axi motor calculator tool out</a>. It may shed some light on the situation. I am curious as to what the 60A/60s means, because on other motors on that page I see 60A/20S. That is really the only part I'm not sure about. Maybe someone else will chime in here... But I think you will be safe sizing it for a max of 77 Amps. To be completely comfortable, it wouldn't hurt email AXI and see what they say: info@modelmotors.cz I hope this helps. Keep me updated on what you choose if you don't mind, Matt

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