Need help for deciding battery.

August 22, 2018, 03:03:40 AM

Hi, am a new member to the group.
I'm making an RC plane own-my-own, so my total payload is around 1.9Kg and my motor is 1440kV and weighs around 78gm and produces thrust around 1.2Kg. And the ESC is around 30 amps. I measured all this stuff on eCalc. I need help to decide the battery requirement, as currently I've a sp4mm3r 450mAh 75C battery. How do I decide which battery is suitable for me?

August 22, 2018, 03:14:41 AM

:::MORE DETAILS:::
Total Plane Weight= 1.9Kg
Empty weight= ~500gm
Wing Span= 110cm
MAC= 11.5cm (Mean Avg. Chord)
AoA=5 degrees (Angle of Attack)
Thrust:Weight ratio= 0.628

::MOTOR DETAILS:: (I'm kinda confused with this 1 too)
Hacker A30-28S V4
Thrust= 1.2Kg
RPM/V= 1440kV
Outrunner
(I can change this motor too, depending upon the battery. I want to keep the weight of the electronics to a minimum tho)
I did some 50-70 iterations on eCalc to find this motor. But if U could suggest me a better one, that's good.

Props= 9x4.5 in
~Noob Here~
ALSO plz help me with the formula (if there's any) for calculating battery requirement or motor's kV requirement.

taksh · August 22, 2018, 08:58:18 AM

why u used disposable (fake) mail to create id on rcindia?

August 23, 2018, 05:44:46 PM

Was having some issues with the main account.
Anyway, any answer for the query plzzzzz.

sanjayrai55 · August 23, 2018, 07:20:42 PM

Check the KV you have written
https://www.hacker-motor-shop.com/Brushless-Motors/Hacker-Outrunner/Hacker-A30/A30-14pole/A30-28-S-V4.htm?shop=hacker_e&SessionId=&a=article&ProdNr=15716110&p=6514
As per this, you would need typically a 1045 SF prop and get 1 kg thrust. You would need a 3S LiPo minimum 2200 mAh 25 C. A 30-40 A ESC

Sent from my Moto G (4) using Tapatalk

sanjayrai55 · August 23, 2018, 07:21:24 PM

BTW Hacker are premium motors, among the best you can buy

Sent from my Moto G (4) using Tapatalk

sanjayrai55 · August 23, 2018, 07:22:14 PM

At ~ 73 EU not surprising 😉

Sent from my Moto G (4) using Tapatalk

taksh · August 23, 2018, 08:58:51 PM

if you know disposable mail then you also know that gmail doesn't need number for registrations.
I can easily easily access your account within few seconds. So, creating new account with disposable is not a solution.
Create new gmail id then make account on rcindia.
can u tell me what is issue with your old account?

K K Iyer · August 23, 2018, 09:36:32 PM

Sanjayrai55's reply gives you a good starting point.
For more info, youhave to providemore data.

Quote from: on August 22, 2018, 03:03:40 AM
I'm making an RC plane own-my-own,
If this your first model, you are tackling too many issues at the same time

so my total payload is around 1.9Kg
Is this the All Up Weight or the payload it has to carry?

and my motor is 1440kV and weighs around 78gm and produces thrust around 1.2Kg.
Pl give details of motor, make, max watts etc

And the ESC is around 30 amps.
Can't be around 30 amps. It's either 30 amps, or a different figure

I measured all this stuff on eCalc.

I need help to decide the battery requirement, as currently I've a sp4mm3r 450mAh 75C battery. How do I decide which battery is suitable for me?

A 450mah can give say 0.3 amps for an hour, 3amps for 6 minutes, or 18 amps for 1 minute.
Or, if it's really 75C, 36 amps for 30 seconds.
If your All Up Weight (not just payload) is about 4lbs, you'll probably need 200-250watts, or about 18amps on a 3s lipo.
So a 450mah lipo will just die after 1 minute!

Hope this helps...
Regards

August 25, 2018, 07:47:24 PM

::Full Details::
Here is my complete Analysis of the components that I'm gonna buy.

Quote from: sanjayrai55 on August 23, 2018, 07:20:42 PM
Check the KV you have written
https://www.hacker-motor-shop.com/Brushless-Motors/Hacker-Outrunner/Hacker-A30/A30-14pole/A30-28-S-V4.htm?shop=hacker_e&SessionId=&a=article&ProdNr=15716110&p=6514
As per this, you would need typically a 1045 SF prop and get 1 kg thrust. You would need a 3S LiPo minimum 2200 mAh 25 C. A 30-40 A ESC

Sent from my Moto G (4) using Tapatalk

Sorry, it was actually Hacker A30-22S-V4 (14 poles)
Here's the link for more details:
https://www.hacker-motor-shop.com/Brushless-Motors/Hacker-Outrunner/Hacker-A30/A30-14pole/A30-22-S-V4.htm?shop=hacker_e&SessionId=&a=article&ProdNr=15716111&p=6514

Quote from: K K Iyer on August 23, 2018, 09:36:32 PM
Sanjayrai55's reply gives you a good starting point.
For more info, youhave to providemore data.

Quote from: on August 22, 2018, 03:03:40 AM
I'm making an RC plane own-my-own,
If this your first model, you are tackling too many issues at the same time

so my total payload is around 1.9Kg
Is this the All Up Weight or the payload it has to carry?

and my motor is 1440kV and weighs around 78gm and produces thrust around 1.2Kg.
Pl give details of motor, make, max watts etc

And the ESC is around 30 amps.
Can't be around 30 amps. It's either 30 amps, or a different figure

I measured all this stuff on eCalc.

I need help to decide the battery requirement, as currently I've a sp4mm3r 450mAh 75C battery. How do I decide which battery is suitable for me?

A 450mah can give say 0.3 amps for an hour, 3amps for 6 minutes, or 18 amps for 1 minute.
Or, if it's really 75C, 36 amps for 30 seconds.
If your All Up Weight (not just payload) is about 4lbs, you'll probably need 200-250watts, or about 18amps on a 3s lipo.
So a 450mah lipo will just die after 1 minute!

Hope this helps...
Regards

Yes, this is the first time I'm making an RC Plane, hence I'm too afraid to fail.
And Yes, my total weight (incl. drive) is 1.9Kg
For more details on motor, plz checkout the below image. I did some research and analysis on the motor.
As far as I know (from various rcforums), my drive current should be enough to fly the plane, what I mean is that:
If i have a 450mAh battery with discharge rate of 75C then:
0.45*75 = 33.75A which should be >= drive-current of the motor@ full throttle. Or (150% of drive-current of the motor@ optimum throttle.)
(Also by ESC around 30Amps, I meant 30 or 40A. As I've both ESC's)

PLZZZZZZ Do review my understanding of this part.
And Thanks Everybody for helping me.
It means a lot.

August 25, 2018, 07:49:48 PM

Quote from: taksh on August 23, 2018, 08:58:51 PM
if you know disposable mail then you also know that gmail doesn't need number for registrations.
I can easily easily access your account within few seconds. So, creating new account with disposable is not a solution.
Create new gmail id then make account on rcindia.
can u tell me what is issue with your old account?

Sorry, will do for sure..

Seems like I'm unable to recover my password and the account is locked for trying too many times.

K K Iyer · August 25, 2018, 08:34:27 PM

Two points to consider
1. C ratings on lipos are often exaggerated. I rarely draw over 10C from a 20C rated lipo.
2. If your 450mah lipo is really high quality, it may be able to power a 400w motor on full load.

And in the process, die in 30 seconds!

If that's hard to believe, try a test on the ground, with a wattmeter connected to see if you're drawing 30-35 amps.

I often recommend trying out a bicycle, before trying out a Harley

But to each his own...

taksh · August 25, 2018, 09:27:46 PM

Quote from: on August 25, 2018, 07:49:48 PM
Quote from: taksh on August 23, 2018, 08:58:51 PM
if you know disposable mail then you also know that gmail doesn't need number for registrations.
I can easily easily access your account within few seconds. So, creating new account with disposable is not a solution.
Create new gmail id then make account on rcindia.
can u tell me what is issue with your old account?

Sorry, will do for sure..
Seems like I'm unable to recover my password and the account is locked for trying too many times.

If you can't recover password and account then you make new accounts instead of using disposable fake mails.
After few months, if you want to login on rcindia then you again forgot password and email and this time, both email as well as password.
Make id with mobile number. If you recover password with mobile number.
It is better for you to use genuine id on rcindia. So, make genuine id on rcindia then repost topic. Users of this forum will help you.
Using fake id on simple website is like exploiting website.

Need help for deciding battery.

document.write(Base64.decode('PGEgaHJlZj0iaHR0cHM6Ly93d3cucmNpbmRpYS5vcmcvaW5kZXgucGhwP2FjdGlvbj1wcm9maWxlO3U9MjExNjkiIHRpdGxlPSJWaWV3IHRoZSBwcm9maWxlIG9mIGI3MTY2ODQzQG53eXRnLm5ldCI+YjcxNjY4NDNAbnd5dGcubmV0PC9hPg=='));[Please enable JavaScript to see this content]

document.write(Base64.decode('PGEgaHJlZj0iaHR0cHM6Ly93d3cucmNpbmRpYS5vcmcvaW5kZXgucGhwP2FjdGlvbj1wcm9maWxlO3U9MjExNjkiIHRpdGxlPSJWaWV3IHRoZSBwcm9maWxlIG9mIGI3MTY2ODQzQG53eXRnLm5ldCI+YjcxNjY4NDNAbnd5dGcubmV0PC9hPg=='));[Please enable JavaScript to see this content]

document.write(Base64.decode('PGEgaHJlZj0iaHR0cHM6Ly93d3cucmNpbmRpYS5vcmcvaW5kZXgucGhwP2FjdGlvbj1wcm9maWxlO3U9MjExNjkiIHRpdGxlPSJWaWV3IHRoZSBwcm9maWxlIG9mIGI3MTY2ODQzQG53eXRnLm5ldCI+YjcxNjY4NDNAbnd5dGcubmV0PC9hPg=='));[Please enable JavaScript to see this content]

document.write(Base64.decode('PGEgaHJlZj0iaHR0cHM6Ly93d3cucmNpbmRpYS5vcmcvaW5kZXgucGhwP2FjdGlvbj1wcm9maWxlO3U9MjExNjkiIHRpdGxlPSJWaWV3IHRoZSBwcm9maWxlIG9mIGI3MTY2ODQzQG53eXRnLm5ldCI+YjcxNjY4NDNAbnd5dGcubmV0PC9hPg=='));[Please enable JavaScript to see this content]

document.write(Base64.decode('PGEgaHJlZj0iaHR0cHM6Ly93d3cucmNpbmRpYS5vcmcvaW5kZXgucGhwP2FjdGlvbj1wcm9maWxlO3U9MjExNjkiIHRpdGxlPSJWaWV3IHRoZSBwcm9maWxlIG9mIGI3MTY2ODQzQG53eXRnLm5ldCI+YjcxNjY4NDNAbnd5dGcubmV0PC9hPg=='));[Please enable JavaScript to see this content]