700 What is the best Speed Controller for the Trex 800.

AlwaysDave

New Member
Batteries: 2 x 12000 mAh 22.2 v = 24000 mAh 44.4 v

The Speed Controller has finally given up, probably over powered it. The standard batteries are two 5200 mAh.

So a more powerful Speed Controller is much needed.
 

Smoggie

Well-Known Member
My personal pick would be the Hobbywing Platinum Pro 160A V4. I have one on my KDS agile 7.2 and another in my Goblin 770, they don't even get worm in those helis. They have the best soft start and governor in the business plus a really powerful and reliable built in BEC so you can dispense with external BECs or Rx packs.
 

Tony

Staff member
If you have two 12000mah packs, you can wire them one of two ways.

Parallel - If wired in parallel, this would give you 24000mah of runtime, but you would still only be at 22.2 volts

Series - If wired in series, you would still have 12000mah of runtime, but your voltage would be 44.4 volts.

Also in parallel, your C rating would theoretically double as well, but not in series.
 

Smoggie

Well-Known Member
PS... I'm surprised you can fit such massive batteries in the frame, have you got an external battery mounting system or something similar?


PPS.. Tony, the C rating doesnt change, it's the same however you wire the batteries. I think lots of people get confused about this one so for the record:

Maximum current (Amps) = C x Ah

If we assume the batteries are 20C rated:
  • For the 24Ah 22.2V parallel wired battery the max amps are 20C x 24Ah= 480A
  • For the 12Ah 44.4V series wired battery the max amps are 20C x 12Ah = 240A

So the C rating stays the same but the actual current rating changes due to the change in capacity. (All a bit academic in this case because I dont suppose the heli will be using anything like 240A?)
 

Tony

Staff member
Correct. I should have worded that differently. By using both batteries in parallel it allows you to pull more amps from the set over what you would from a single battery.

But Steve is correct, how in the world are you carrying 24000mah worth of 6s packs on an 800 size helicopter? Pics would be awesome.
 

Geena

Staff member
Going by the size of those batteries, my guess is they are being used in an FPV or aerial photography rig. I can`t see packs like that being used for a 3D helicopter, even in an 800. As far as the original question goes...I would recommend the Hobbywing Platinum 160A, or the Platinum 200A. Or the new Scorpion Tribunus 200A.
 

AlwaysDave

New Member
PS... I'm surprised you can fit such massive batteries in the frame, have you got an external battery mounting system or something similar?


PPS.. Tony, the C rating doesnt change, it's the same however you wire the batteries. I think lots of people get confused about this one so for the record:

Maximum current (Amps) = C x Ah

If we assume the batteries are 20C rated:
  • For the 24Ah 22.2V parallel wired battery the max amps are 20C x 24Ah= 480A
  • For the 12Ah 44.4V series wired battery the max amps are 20C x 12Ah = 240A

So the C rating stays the same but the actual current rating changes due to the change in capacity. (All a bit academic in this case because I dont suppose the heli will be using anything like 240A?)
I have removed the battery cradle. The batteries now sit on the frame with the Velcro straps attached. At one point I even tried the single Tattu 22000 mAh battery but found that I need 44.4 volts to run the Heli and yes it does fit in, just.

With these two batteries, it is heavy, I'm about ¾ up on the collective before it rotates. The standard batteries only gave me about 5 minutes flying time but, these two batteries I'm getting about 20 minutes to half an hour.
 

AlwaysDave

New Member
If you have two 12000mah packs, you can wire them one of two ways.

Parallel - If wired in parallel, this would give you 24000mah of runtime, but you would still only be at 22.2 volts

Series - If wired in series, you would still have 12000mah of runtime, but your voltage would be 44.4 volts.

Also in parallel, your C rating would theoretically double as well, but not in series.
I need 44.4 volts to run the Heli as advised by Bob at Sussex Model Centre in Worthing.
 

AlwaysDave

New Member
Correct. I should have worded that differently. By using both batteries in parallel it allows you to pull more amps from the set over what you would from a single battery.

But Steve is correct, how in the world are you carrying 24000mah worth of 6s packs on an 800 size helicopter? Pics would be awesome.
I don't fly 3D or inverted just normal flying and that's all I'm interested in. I have two GoPro Hero 3 camera's on the Heli one facing forwards and the other facing down.
 

Smoggie

Well-Known Member
So how do you fit those huge batteries in the heli? I have a Trex 700 which uses the same frame as the 800 and the standard 2 x 5000mAh batteries are a quite tight fit. I once ran into a guy that used a Trex 800 for aerial photography, he had a huge battery box slung under the frame, have you got something similar?
 

AlwaysDave

New Member
I have recently bought the Hobbywing Platinum HV-200A-OPTO and the three wires coming out of the Controller are NOT colour coordinated unlike the Phoenix ice 2 which I'm replacing. The motor has Black, Red & Blue so how do I know what wire goes where?

The PDF manual doesn't help.
 

Tony

Staff member
On brushless motors, it doesn't matter where you put the wires from the ESC to the motor. If the motor runs backwards, then just swap around any two wires and you are good.
 

Smoggie

Well-Known Member
As Tony said, the way you connect the wires is not important, the colours dont mean anything. Other than direction of rotation the way you connect them makes no difference. If the motor spins backward then swap any two of the three wires and it will reverse rotation direction, alternatively reverse direction in the ESC software.
 

Geena

Staff member
As Smoggie said, with Hobbywing, Scorpion, and a lot of other ESCs, you don`t even have to swap the wire around to change motor rotation direction. You can do it right in the programming software.
 

AlwaysDave

New Member
Thank you as always for your good advise but, I'm not anywhere near advanced as you are. Flying the Heli is the easiest bit :beguiled:

Looking at the picture, the Red wire comes out to the left and the Black one to the right, what colour wire's from the batteries go where. I've read the instructions and nowhere does it state this.
 

Smoggie

Well-Known Member
On the battery connection colour is VERY important!.. It's pretty obvious, it's simply red to red and black to black. Get that wrong and it's new ESC time.
 
Last edited:

AlwaysDave

New Member
On the battery connection colour is VERY important!.. It's pretty obvious, it's simply red to red and black to black. Get that wrong and it's new ESC time.
Ok, the red one from the ESC connects to the red lead on the top battery (picture above), then the black lead runs round to the bottom battery, I now have two black leads going to the bottom battery, which lead connects to the red one on the bottom battery?
 
Top Bottom