Batteries My Goblin 700 and its batteries...

sprevin

New Member
Hey guys,....I am by no means new to RC Heli's, built, owned and flown many 450's and 500's but never a 700 size electric heli and I have recently hit a wall. I am now the proud father of a Goblin 700 that is nearing completion and all that is left to purchase the batteries. This is where I need your eperience (and thanks in advance for any given).

I have searched the forums on this and many websites but found nothing specific to my question....How do I match the best batteries to my specific motor, esc and flying style? I know it sounds kinda like a nub question but this is my first 700 size heli and I cant quite wrap my head around the numbers. Here are my specs;

Scorpion Commander V 12-50V 130A ESC (OPTO)
Specifications


Max Continuous Current 130 Amps
Operating Voltage Range 12 to 50 Volts
Max BEC Output No BEC
On Resistance 0.68 mOhms



Scorpion HK-4035-560KV

Stator Diameter 40 mm (1.57 in)
Stator Thickness 35 mm (1.024 in)
No. of Stator Arms 12
Magnet Poles 10
Motor Wind 8 Turn Delta
Motor Wire 23 - Strand 0.29mm
Motor Kv 560KV RPM / Volt
No-Load Current (IO) 2.24 Amps @ 10v
Motor Resistance (RM) 0.014 Ohms
Max Continuous Current 100 Amps
Max Continuous Power 4200 Watts
Weight 460 Grams (16.22 oz)
Outside Diameter 49.98 mm (1.97 in)
Shaft Diameter 5.98 mm (0.235 in)
Body Length 61.8 mm (2.43 in)
Overall Shaft Length 100.0 mm (3.93 in)
Max Lipo Cell 12s
Peak Current 120A (5 seconds)
Peak Power 5200 Watts (5 seconds)
Motor Timing 5deg
Drive Frequency 8kHz

Now I know from reading the literature that I can use up to a 12 cell LiPo but how do I decide what's best in terms of mAh? 5000 would obviously last a bit longer, but would it run my electronics too hot? Does a single battery pack have any discernable advantages as opposed to dual 6 cell packs? My flying style is very light 3D. I usually only fly once or twice a week at the most. Any thoughts or recommendations would be much appreciated.
 

murankar

Staff member
As long as your packs can supply more amps than the entire systems demands your good. Most people can get away with a 30-35C packs. At 30C you should be able to supply enough amps. As a disclaimer do not believe the printed C rating. It's not to accurate now a days.


Keep in mind your esc can handle up-to 130 amps and spikes that are much higher. Your motor is about 100 Amps continuous, which means your motor (without spiking) will only pull 100 amps which is under the rating of your esc. So if your packs put out 150 amps or more you'll be fine.

12S will be the best setup for your heli. How you do this is up to you. You can buy a pre made stick pack which is 2 6s packs or you can make your own. What capacity you need will be based on what disk loading you want. You will have to chose. Light disk loading is floaty and will have shorter flight times, heavier disk loading will be more crisp and suited for "box flying". Other aspects to longer flights is head speed. My Gaui X3 will net me around 6.5 - 7 minutes because my head speed is way low for a 360 class heli.
 
Last edited:

Smoggie

Well-Known Member
Previous advice is all good. Your chosen motor is on the smaller side for the G700, it will still have enough power to fly the 700 fine for sports type flying but you might want to go for a battery slightly on the lighter end of the scale to prevent overworking the motor by hauling around a heavy heli. I have this same motor in my Goblin 630 and even in that heli it gets quite toasty. Something like 2 x 6s 4500 packs should work very well, you would probably be ok up to 5000mAh but no bigger.

The Goblin is actually pretty flexible when it comes to batteries so you would be hard pushed to find a battery that wouldn't physically fit. Higher the C rate the better, I'd go for at least 35C.

By the way.. with the (quite high) 560Kv motor you should fit a smaller front pulley, 19t would be about right.
 
Top Bottom