what C rating to go for

[Yosser70]

Sorry for all the questions but truing to get things together for my hexa and want to try and get it right.

I';m looking into what batteries to get and not sure what C rating to go for. I know the higher the better as far as safety and not damaging the battery goes but the higher the C rating the more expensive they get and I want to keep the cost down as much as possible! I';ll be running 6 Turnigy D2830 1000kv motors with 1047 props and want to know what C rating I need on my batteries so any help would be great. Also thinking of running it with 2 batteries at some point if that makes a difference.

Cheers

[rickp]

How many cells?

[guest325]

I would probably go for something like this:
http://www.hobbyking.com/hobbyking/store/__32101__ZIPPY_Compact_4000mAh_3S_25C_Lipo_Pack_UK_Warehouse_.html

[SimonS]

In theory..... You should look at how much each motor can draw and that should give you your total maximum draw.
C rating multiplied by the pack capacity (eg 25x4A) gives the max for the pack and this should be higher than the max draw, but.....
If you use a Naza controller and only use GPS or ATTI you can get away with less.  As an example, my Hexa weighs about 4.5kg. It has 6 TigerMotor 4012 motors, each max 25A. 25x6 is 150A.  The Hexa hovers at 26A and a flat out climb is 55A so with a 25C 5000mAh I am only using about 45% of the max continuous current rating of the LiPo.  This is all down to the fact that the Naza restricts the max climb rate hence less power required.

[fruitsalad]

im using same motors im using 9x4.7 props more than enough power..
zippy 2800mah 30c lipo..
good flight times..

[Yosser70]

I would probably go for something like this:
http://www.hobbyking.com/hobbyking/store/__32101__ZIPPY_Compact_4000mAh_3S_25C_Lipo_Pack_UK_Warehouse_.html

Would that 25c rating be ok on a hexa? It';d be good if it is as that';s a good price for a 4000mah battery

[guest325]

Work it out, 25C 4Ah = 100A but burst current =35C = 140A; should eat anything you';ve going to throw at it!
You may need 9x4.7 props though, higher volts = faster rpm really need to check with a watt meter to be sure.

[Yosser70]

Work it out, 25C 4Ah = 100A but burst current =35C = 140A; should eat anything you';ve going to throw at it!

So it';s 25c per 1000mah and not 25c in total?

[guest325]

So it';s 25c per 1000mah and not 25c in total?

4000 mah = 4ah so 25 (C) x 4 (4000mah) = 100A, hope this helps you understand!

[guest325]

4000 mah = 4ah so 25 (C) x 4 (4000mah) = 100A, hope this helps you understand!

It used to do my head in as well, don';t worry,  it';s maths and common sense!

[Yosser70]

OK cool, I';ve jut not seen it explained like that before.