Simple question? (motor->ESC->battery)

Maxdem

Maxdem

Member
Hi there,

I'm doing my first quad-build and I have already bought 4 motors and 4 ESC's. Now I only need to buy a battery. I was planning to buy this one or this lighter on.

With the 1500mAh battery I have about 52.5 excess Amps and with the lighter 900mAh I have about 22.5 excess Amps in comparison with the 7.61 Amps per motor. The 900mAh Lipo is 62grams lighter than the 1500mAh Lipo.

What Lipo battery should I use for my quad? Would appreciate some advice! :D
 
GJH105775

GJH105775

Off and on
Moderator
Maxdem said:
Hi there,

I'm doing my first quad-build and I have already bought 4 motors and 4 ESC's. Now I only need to buy a battery. I was planning to buy this one or this lighter on.

With the 1500mAh battery I have about 52.5 excess Amps and with the lighter 900mAh I have about 22.5 excess Amps in comparison with the 7.61 Amps per motor. The 900mAh Lipo is 62grams lighter than the 1500mAh Lipo.

What Lipo battery should I use for my quad? Would appreciate some advice! :D
Click to expand...

How are you calculating the amps needed and amps able to be supplied.
 
Maxdem

Maxdem

Member
Jackson said:
The second one, 900mAh is only 2s/7.4V. You don't want that. And with the ESCs you will need a UBEC to drive your FCB and RX.

http://www.banggood.com/Hobbywing-3A-UBEC-5V-6V-Switch-Mode-BEC-For-RC-Models-p-915037.html
http://www.banggood.com/External-Brushless-BEC-UBEC-3A-5V2-5S-Receiver-Power-Supply-p-949258.html

There are more, read the reviews.
Click to expand...
Thanks for the advice! So I should better go with the 1500mAh Lipo. And about the UBEC to drive my receiver and FCB: how many do I need of these? I've chosen for the 2nd UBEC you've suggested because it's half the weight of the 1st UBEC. Or I could go for a PDB with in-build UBEC for I'm still thinking about getting a PDB for my first build cause I've heard it's easier with less soldering. Any advice what to pick? ;)
 
Maxdem

Maxdem

Member
GJH105775 said:
How are you calculating the amps needed and amps able to be supplied.
Click to expand...
I used this link to calculate the Amps.

The max. Amps one BE1806 motor will draw is Max. Power / Lipo volts = 84.4(W) / 11.1(V)= 7.61A.

My ESC's can handle 12A each.

The 1500mAh Lipo Amps are calculated with: (Lipo mAh rating * C-rating) / 1000 = (1500 * 35) / 1000 = 52.5A

According to the link I used you can calculate the excess Amps simply by doing: Lipo Amps - Motor Amps = 52.5 - 7.61 =44.89 excess Amps. Which is stated as an overkill in the link therefore I started doubting if I chose the right battery. I hope my calculations are correct ; )
 
Jackson

Jackson

USA member at large
And about the UBEC to drive my receiver and FCB: how many do I need
Click to expand...
You need one. A single UBEC (as will a single BEC equipped ESC) power the FCB, the FCB will then power the RX.

Maxdem said:
I've chosen for the 2nd UBEC you've suggested because it's half the weight of the 1st UBEC
Click to expand...
Part of the extra weight is due to the ferrite ring which helps to clean up/filter the output. A consideration if you go to FPV.
SKU075857.3.JPG


That is an expensive specialized PDB with extra stuff you don't need that you linked to.

Look here, and again read the reviews.
http://www.banggood.com/buy/5V-power-Distribution-Board.html

Here's the $4.16 one with an explanation.

 
Jackson

Jackson

USA member at large
Maxdem said:
The 1500mAh Lipo Amps are calculated with: (Lipo mAh rating * C-rating) / 1000 = (1500 * 35) / 1000 = 52.5A

According to the link I used you can calculate the excess Amps simply by doing: Lipo Amps - Motor Amps = 52.5 - 7.61 =44.89 excess Amps.
Click to expand...
Motor amps = 7.61 x 4 = 30.44. Lipo amps 52.5 - 30.44 = 22.06 excess amps.
 
Maxdem

Maxdem

Member
Jackson said:
You need one. A single UBEC (as will a single BEC equipped ESC) power the FCB, the FCB will then power the RX.


Part of the extra weight is due to the ferrite ring which helps to clean up/filter the output. A consideration if you go to FPV.
SKU075857.3.JPG


That is an expensive specialized PDB with extra stuff you don't need that you linked to.

Look here, and again read the reviews.
http://www.banggood.com/buy/5V-power-Distribution-Board.html

Here's the $4.16 one with an explanation.

Click to expand...
Okay, seems like the UBEC with the ferrite ring would be a better choice bc later on I'd want to go for FPV.

I've read a lot of reviews about the PDB you suggested and there seems to be a chance of getting the pdb with too great volt differences. Still I'll go for this PDB: it's the same size as the CC3D which I'm going to buy today.

Do you have any recommandations on what version of the CC3D I have to buy? This one, these or one of those ?

Sorry if I ask too much. As a newbie there seem to be so many items where you don't know what to choose and if it will work.

Thanks a lot for your help!
 
GJH105775

GJH105775

Off and on
Moderator
Maxdem said:
Okay, seems like the UBEC with the ferrite ring would be a better choice bc later on I'd want to go for FPV.

I've read a lot of reviews about the PDB you suggested and there seems to be a chance of getting the pdb with too great volt differences. Still I'll go for this PDB: it's the same size as the CC3D which I'm going to buy today.

Do you have any recommandations on what version of the CC3D I have to buy? This one, these or one of those ?

Sorry if I ask too much. As a newbie there seem to be so many items where you don't know what to choose and if it will work.

Thanks a lot for your help!
Click to expand...
I'd get the one with 90 degree pins, simply as it is neater and has less strain on the cables
 
Maxdem

Maxdem

Member
Jackson said:
Why not use the nice vibration damper assembly they give you?
Click to expand...

I thought some standoffs would be more solid. Learnt about it by this youtuber. (you'd probably know him) Also, I'm planning to mount the CC3D above the PDB like is shown in this picture
16_AluminumPosts_zps59d29cb8.jpg

Still thanks for the tip! I will probably find another purpose for the vibration damper if I won't use it for mounting the FC.
 
Maxdem

Maxdem

Member
Okay, I've ordered the CC3D and the PDB. Only need to find a few nylon standoffs (instead of hundreds in a box) to mount the FC + PDB.

Further I need to find a cheap transmitter and a receiver. And a lipo-charger for this battery.

Maybe some Loctite will be good for the bolts although I haven't found it yet on Banggood.

Only these few items and then...I'M FULLY READY TO START THE BUILD :D:D:D:D:D (before I find out I'm missing something ;d)
 
Jackson

Jackson

USA member at large
Maxdem said:
I thought some standoffs would be more solid.
Click to expand...
You don't want 'solid' with the CC3D or KK2 you'll often see them being attached with foam tape so as to isolate the CC3D from frame/motor vibrations.

And this is the build series you should watch.


Well good luck.
 
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