Unexpectedly short flight times

J

Jareth_Atian

Member
Hey, all.

I have a dji-F550 that weighs in at 2528 grams, and I'm getting only around 5 minutes of flight time even though I'm using a 4s5000mah battery. According to E-calc, I should be getting closer to 11 minutes flight time at that weight with my current motors. I am running my gimble, video transmitter and LED's off the same flight battery (using BEC's to alter voltage as needed), but I wouldn't expect for the added load to be *THAT* significant. Motors aren't hot, it flies beautifully and lifts off easily, no real difficulties at all...except for unexpectedly short flight times.

Could folks have a look at my setup and let me what I should be doing differently? Should I buy larger batteries, carry secondary batteries, etc? Thanks,

- Jareth

Frame: DJI Firewheel F550
Landing Gear: AeroXcraft landing gear w. vibration isolator kit
Speed Controllers: DJI Opto 30Amp ESC
Flight Controller: DJI Naza-M w. GPS
Motors: Century/HWC 2216 900Kv Brushless Motors
Batteries: 4s5000mah
Propellers: Aerial Media Pros 9x5 Carbon Fiber Propellers
Camera: GoPro HERO3
7.4V for Gimbal: Castle Creations BEC Pro
Gimbal: AeroXcraft GoPro Brushless Gimbal
12V for video + LEDs: 12V 4.5A UBEC from HobbyKing
Video Transmitter: FatShark 5.8ghz, 250mw video transmitter
Lights: CooperUAV LED Light kit for DJI F550
 

L

Langdale

Member
What are you using to time your flight? If you're using the voltage warning on the Naza, is it set at the right levels?
What are you putting back in to the battery when you're charging it?

I stopped using the voltage alarm and set the timer on the Tx to 6 mins and I'm putting back in on average 2500mah, so I'm going to up the timer a little.
 

D

Dewster

Member
I converted a DJI F550 to a Y6. My flight times were 6.5 to 7 minutes using two 3S l6000 mah lipos in parallel. The batteries ran FPV video transmitter, motors, etc. Everything was powered off of the flight batteries. My craft was heavy.. Weighing in a just over seven pounds with my Sony Action cam hard mounted- no gimbal.

Keeping your weight down is the first step for increasing flight times.

Good props will increase flight time. I gained 10-15 seconds by switching from APC props to Graupner E-props.

Lipos batteries. You may want to consider 4S Lipos. Just make sure your smaller electronics can handle the increased power: FPV camera/transmitter etc. Running 3S lipos in parallel may increase flight time, but it also adds weight. You'll need to find the balance.

You can also consider running your video transmitter off of a second lipo instead of the flight battery. Just make sure that you don't run out of power and lose video while flying FPV.

Voltage Monitor - I can't say enough about this one... Watch your settings. Don't take risks in an effort to stretch flight times, especially of you are using old batteries. As they age you will get shorter flight times. My Y6 went into DJI's second level voltage protection while I was landing. The second level protection reduced throttle so much that my craft fell from the sky. The only thing that level of protection will do is keep your craft level on a fast descent. The best thing to do while experimenting with flight times is use a $3 dollar lipo checker with alarm. Don't stretch the settings of the voltage protection monitor, because you may find yourself in the red before you realize it. You may want to consider turning it off. Use the lipo checker so that your craft will stay in the air. Look at how much power you are putting back in the lipos to stay within the "80% capacity rule".
 



J

Jareth_Atian

Member
I was judging flight time until the second-level voltage protection warning went off...but it's very possible that I have my voltage protection settings incorrect, causing premature power-loss. I'll spend some time fiddling with that over the next weekend. Thanks, folks!
 

You must log in or register to reply here.
Top