jstanton

My Feedback: (14)

I have the great planes suhkoi 3d electric with a Walkera 3200kv in a Hi-Max gear box using the 4.4 to 1 gears. It came with a 30A esc by Walkera that I was told is for helicopters. The 30A ESC does not have any brake. I also purchased a 1800 Li-Po battery from the same guy on E-bay. I am only getting about 5 minute run time on this setup. The people at Walkera are very nice, but they say it is working correctly. I thought I should be getting about 20 minutes with this 1800mah Li-po. I know this setup was for a helicopter and I installed it on a plane, but I was sure the run time would be longer than 5 minutes. Am I looking at this all wrong? I am new to this electric thing, but I am welling to learn.

Thanks

Matt Kirsch

My Feedback: (21)

How are you making your determination that the flight should last 20 minutes? The best way to estimate flight duration is to divide the capacity of the battery by the average current drawn by the motor. Full-throttle current could be used as a "worst case" scenario.

Do you have an idea of how many Amps this setup should be drawing? If not, how many cells are in the pack?

Overloading the pack will cause it to lose power quicker than expected. What is the C rating on this pack? Ebay packs are often overrated, or of poor quality unless you buy name-brand packs.

Does the ESC have a programmable cutoff? What is it set at?

jstanton

My Feedback: (14)

Matt

The Li-Po bettery looks like the generic Li-Po. It has no name brand, but says it is a 1800mah 11.1 volt 3 cell pack.
Here are the Spec's on the battery from the person I bought it from.

Specifications:
>Size: 71mm*32mm*27mm
>Flying Time: Over 20min (Continuos)
>Charger Time: About 60min
>Charger Function: Auto turn OFF
>Volt: 11.1v
>Weight: 110gram
>For use the helicopter or plane: Hummingbird, Feda, E-Sky, Dragonfly, Aerohawk or other mini helicopter

Her are the spec's on the motor:

Brushless Motor specifications:
Very powerful Brushless Motor 180 ~!!!
Working Voltage : 6-18V
Speed Constant : 3200RPM/V
Hollow holding current : ?1A
Impend-dance : 87m?
Dimension : ?20 X 40mm
Diameter of axes : ?2.3mm
Diameter:20.0mm
Length:47.5mm
Length of axes : 13.5mm
Installation bore depth : 3.5mm
Weight : 65g
(30A speed Controlle)for brushless motor

Thanks for your help.

biggy boy

Hi jim
charge the battery and remove it from the charger using a volt meter check the voltage of the pack it should be over 11.1 at full charge.
I charge mine to 12.75 volts that 4.24 volts per cell.
If it is not over 12 volts then there is a problem with the charger.
With my 2100 pack I get over 33 min flight time with that motor and a 12x6 prop and 6.6:1 gearbox.
you are using the 11x 7 prop? on a 4.4:1 gearbox
With this setup your full throttle amps would be about 14.5 amps
at full throttle your battery would last aprox 7.5 minutes
are you using full throttle for the whole flight?

Glen

jstanton

My Feedback: (14)

Glen

Thanks for the feed back on this. I am new to electics so I was not sure on how much time I should be getting. I was running mostly wide open becasue the planes weighs in at 26oz. I have cut back to half throttle for about half of the flight time now and I am still only getting 5 minutes flight time. I went out and bought a new battery e-zone charger made just for Li-Po's and I will check and see how much off a charge I am getting with this new charger. I believe I am not getting a full charge with the charger that came with the battery. Again thanks for the help.

Thanks

biggy boy

Let us know how long the battery lasts after charging with the new charger.
If this works out good I'll be buying that same package from the same seller, it's a killer price.
I'm not worried about the charger that comes with it I'll just throw it out and use the one I already have.

Glen