RC Groups

RC Groups
    Multirotor Talk
        Discussion Battery selection for DJI F550 hex kit

#1 copters3d Feb 28, 2012 11:48 AM

Battery selection for DJI F550 hex kit
 
HI

I am going to be building my first multicopter (settled on DJI F550 ARF with NAZA). Quick question (yes I am total newbie) - I was told to get a 4S 4000-6000ma battery. I can see a few options on the internet but with different C ratings 30C vs 40C vs 50C. Can anyone provide some recommendations here? I don't understand the difference, but want an optimal choice for my set up in terms of flight time and power (I am using the stock DJI motors). Thanks

#2 copters3d Feb 29, 2012 06:35 AM

Anyone?

#3 Telrin Feb 29, 2012 07:11 AM

OK, let's see if I can help a little.

The 'C' rating tells you how much current you can reasonably expect the pack to deliver but it is a very vague number in most cases as the quoted rating is not usually based on cells assembled into a pack but special testing on a single cell in very favorable circumstances :)

So for a 5000mAh pack with a 40C rating they are claiming it can support up to 200 amps continuous, which few if any of them actually will, but fortunately you are not likely to be drawing that much either ...

The other consideration is that weight tends to increase along with higher C ratings (and capacity) and you don't want to carry more weight than you need.

In the absence of any specific recommendations from others I'd say don't go beyond a 40C pack and in all probability a 30C pack would still be perfectly adequate.

Now, a brief question in return :)

Did your F550 ship with both 8" and 10" props?

Just curious as the manual lists both in the box, but mine only had 10" included.

Just wondering if that is 'normal' or if something got left out by accident?

#4 piccoloflyer Mar 01, 2012 06:05 PM

30C should be enough, my F550 comes with both 8 x 8" and 8 x 10" prop

#5 Michael64 Mar 01, 2012 07:47 PM

The higher C rating means the more current output of the battery, which help save the battery and make it last longer meaning more cycles. The lower C rating will work but for more power and longer lasting battery go to the higher C Rate 40 or 50 will be more than enough but you can even go higher it will not hurt angthing you just end up with cooler running battery and can charge it quicker as well.

Michae64

#6 copters3d Mar 02, 2012 04:25 AM

Quote:

Originally Posted by Telrin (Post 20892465)
OK, let's see if I can help a little.

The 'C' rating tells you how much current you can reasonably expect the pack to deliver but it is a very vague number in most cases as the quoted rating is not usually based on cells assembled into a pack but special testing on a single cell in very favorable circumstances :)

So for a 5000mAh pack with a 40C rating they are claiming it can support up to 200 amps continuous, which few if any of them actually will, but fortunately you are not likely to be drawing that much either ...

The other consideration is that weight tends to increase along with higher C ratings (and capacity) and you don't want to carry more weight than you need.

In the absence of any specific recommendations from others I'd say don't go beyond a 40C pack and in all probability a 30C pack would still be perfectly adequate.

Now, a brief question in return :)

Did your F550 ship with both 8" and 10" props?

Just curious as the manual lists both in the box, but mine only had 10" included.

Just wondering if that is 'normal' or if something got left out by accident?

Thanks. That certainly clarifies. As for the props - have not received kit yet but it does say a pair of 10" and 8" -which is puzzling. Would one put different size props on a single craft?

#7 Telrin Mar 02, 2012 05:01 AM

Quote:

Originally Posted by copters3d (Post 20912631)
Thanks. That certainly clarifies. As for the props - have not received kit yet but it does say a pair of 10" and 8" -which is puzzling. Would one put different size props on a single craft?

No, you will need 6 the same size.

Each 'pair' is one CW and one CCW of the same size, so 3 pairs gets you a set.

#8 piccoloflyer Mar 02, 2012 05:55 PM

8" prop is for 4S, use 10" if you have 3S lipo, my F550 hover at 22amp using 3S 35C battery.

#9 yoadrian Mar 26, 2012 01:21 PM

What kind of flight time can you expect with a 5000mah 3S pack stock with no payload?

#10 MCrites Mar 26, 2012 01:26 PM

3s and 10inch props = higher payload
4s and 8inch props = more sport flying

There are so many variables to flight times... it's easy to assume about 10 minutes depending on weight and how you fly. More sport flying = less time, general hover = more time. It's best to just test it then check your battery to see how much you ran it down (I start with 6 mins.... then 8.... then 10mins...

#11 Velociraptor73 Mar 26, 2012 10:00 PM

Quote:

Originally Posted by MCrites (Post 21147870)
3s and 10inch props = higher payload
4s and 8inch props = more sport flying

There are so many variables to flight times... it's easy to assume about 10 minutes depending on weight and how you fly. More sport flying = less time, general hover = more time. It's best to just test it then check your battery to see how much you ran it down (I start with 6 mins.... then 8.... then 10mins...

I think hovering consumes more power then flying forward.

#12 MCrites Mar 27, 2012 07:43 AM

I guess it depends on definition. In general hover I do move around a bit, just easy level flight @ 50% throttle. When I am sport flying I am almost constantly above 50% throttle in climbs and banked turns. More throttle = more RPM = more juice to run the motors

#13 BillzillaAus Mar 27, 2012 08:09 AM

Quote:

Originally Posted by MCrites (Post 21147870)
3s and 10inch props = higher payload
4s and 8inch props = more sport flying

I'm curious about why that is so?

#14 Kattinkc Jun 07, 2012 04:37 PM

Got two coming
 
Getting tired/bored of my f450 and 550 so I order two bare kits, BBB, from HobbyCool and some spare parts .. Ordered my fourth NAZA from HeliProz.. After adding it up (motors and esc) I might as well have bought the full kit but was afraid of the OEM NAZA and it's oddities. . Of course we are waiting on the NAZA GPSs this month probably not supported on BBB version I would think.

Thanks for the thread as it made up my mind. I have been waiting on HK to get theirs but free freight (HL) and almost instant gratification makes it better. Even though I had to buy motors this way. Thanks again.

#15 Velociraptor73 Jun 07, 2012 10:13 PM

Quote:

Originally Posted by Velociraptor73 (Post 21152622)
I think hovering consumes more power then flying forward.

Yep, I was wrong! Hovering gives me considerable more time on the air than flying around.


All times are GMT -5. The time now is 03:03 PM.