G20 Power Usage for 1/2 Tank of Fuel ??

[Gyan]

Ok this is the setup; stock Zenoah ignition, 3X align 610 servos on the cyclic & 1 Futaba S9256 on the tail. None of the servos were working much cause this was all done in a hover 1ft off the ground. The ignition has a 2200Ma 4 sub C cell NiCad and the system uses a 1850 4 sub C cell NiCad pack both are independent of each other during charge & use. I used up 1/2 tank of fuel in each of 4 flights for an average usage of 580 Ma per flight per each battery pack for a total of 1160 Ma. Since the Ignition system draw is dependent on RPM all flights were done at 1650 rotor speed. Does this sound right to you guys? I think it's drawing too much power. Do you think I can fly for at least a full tank without charging, or is this pushing it?

With the onboard GEM 2000 I have the light goes steady after about 1 minute, I land & drop RPM then it goes back to normal. (The Gem 2000 manual says I have about 30% power remaining if that happens.) Get into a hover & it goes steady again, so I'm assuming the ignition is drawing the voltage down.

[Bustedmp]

I haven't checked the power usage on mine yet, but I am using a 2s 4200mah life pack to power everything. It supplies full pack voltage to the radio gear, and a CC bec drops the ignition voltage to 4.8v. The stock zenoah cdi is supposed to run clear down to 3.1v. I wouldn't ever run that low, because my radio gear would go ape way before the pack gets there. The last charge on my pack it took 2748mah, but that was a few short flights and a bit of setup work. I haven't had a charge on the pack yet that involved only flying, According to the info I found about the stock cdi current draw it is between 1.6 and 2.2 amps. Now on a 15 minute flight that would be between 375 and 550 mah per flight.

[Gyan]

I didn't know the stock cdi would run at 3.1v . Seems about ballpark for the cdi draw in my case. I hesitate putting different batteries on board cause I'm going to set up a generator for it.

[Bustedmp]

I got the info from http://www.toni-clark.com/ftp/ZG20_en.pdf pg7.

[Bustedmp]

It is for the black Zenoah igniton box. Not sure I would feel comfortable running that low though.

[MotorRotor]

The consumption will vary a bit by rotor speed but I have found not as much as I anticipated.

I am now using an 11.1V 3S/1500 pack going through a Scott Gray regulator at 6 Volt on an RCExcel EI unit. It consumes 280 to 300 mah in a twelve minute flight. This supplying the radio and the EI.

Converting that to watt hours. That would be 11.1 x .3 = 3.3 watts / .2 = 16.65 watts per hour.

When I was running the stock Zenoah EI, with a 4.8V1500 mah NiMh pack to only drive the EI, it would consume about 380mah in a 12 minute flight.

That works out to 4.8 x .38 = 1.824 watts / .2 = 9.12 watts per hour. NOTE that this was just to drive the EI unit, I also had a second 4.8v/1500 pack to supply the radio gear. It consumed about the same for a 12 minute flight. So a total of 9.12 x 2 = 18.24 watts per hour.

This works out to what one might expect as the difference is in the difference in efficiency of the two different EI units, proving that the RCExcel unit is supposed to be a bit more efficient then the stock Zenoah unit, and it can also operate using higher voltages.

[Gyan]

Thanks for the replies, I'm running a 2200 Ma Nicad for the EI & 1850 Ma Nicad for the heli. With consumption levels the way they are it seems I'm only good for a 15 min flight until I get the regulator components & I build an onboard generator for it. That's basically what I needed to know. These mechanics are going into a B206 fuse eventually.