Flying Backwards with Multistar 4000mah

[Alan Tochterman]

I just finished modifying the door on my FC40 to accommodate a Multistar 4000 mah battery. It slides in and out with ease and the door closes. I have a great deal of add-ons and was not sure if the extra weight afforded by the battery would be a problem. I am now weighing in at 1175 grams without blade guards nor the PMU that I am about to install.

Anyway, I began a sort test to see if the FC40 would fly. It has no problem taking off. I also am running T-Motors, that too is a help. But when I want it to hover it starts to move backwards. When I replace the battery with a standard one, the FC40 stays in place perfectly. I repeated the process and it only occurs with the new battery.

I assume that the weight of the battery is just enough to "tip" the quad of center. I re-set my compass. Since there are no trim controls on these controllers, do any of you out there have a suggestion for possibly adjusting the gain through the Naza software ?

For now, I have no plans to back to 2200mah batteries. The Multistars are only $19.00 at Hobby King and if I can get 15 min of flight time I will be a happy camper.

Any thoughts ?

 

[Monte55]

Which props are you using? I recently modded one of my P1s to use the Multistar 4000 battery. This one also carries a gimbal and Gopro camera. I also use the 9450 props on it. Better flight time. With the gimbal and camera off, it flies better with stock props. Without camera and 9450 props, it didn't seem as stable. The quad should still not drift much even if a bit off balance. GPS corrects that unless you are talking in atti mode.

 

[Alan Tochterman]

Thank you for responding. I am using 9450s, a FeiYu Tech 2D mini gimbal and a GoPro Knock off. The problem only occurs with the heavier battery. I am in GPS mode and I was able to sync with satellites before launch. I did not take a video, however it moves straight back and quite quickly. It will fly forward if I direct it. However once I release the control, it immediately starts moving straight back. I tired both GPS and ATTI modes. If I use the standard battery, it holds its place nicely.

 

[Monte55]

I don't understand why just the battery would do that. Since you will be using the 4000 battery, I suggest that you connect to assistant software with that battery and check all your parameters. Do advanced IMU calibration and check tx calibration. Check compass mod value. keep all metal away while doing this.

 

[Alan Tochterman]

I will try that. Again, thank you. It is strange. I will try the advanced calabration, using my laptop and a long usb cable to avoid any magnetic interference. I was wondering if a) it is the weight of the battery causing the drone to become off balanced, or if 2) it is creating some type of magnetic interference. If it is the latter, the recalibration should help.

 

[Monte55]

You say you have other things connected to the quad. If a calibration doesn't change anything, I would try to fly it with nothing on the quad to see if that makes a difference. The larger battery didn't change the way mine flies. Although I get more time with the larger battery, it's not as long as some have claimed. With gimbal and camera I can get around 13 minutes until I start to see red flashes. When I check the battery immediately after flight, it's not as low as a stock 2200 battery. I could lower my voltage settings in assistant but I would rather have the reserve power. Anytime you add or take off extra stuff always make sure you have a good compass calibration.

 

[dtitus6297]

These 4000 batteries have a lot of voltage sag so you can lower your naza voltage settings and still b ok. They also don't respond well to heavy flying. If your a slow flyer, they will do you well. I use these and some other 2700mah batteries for when I want to do some fast flying

Sent from my SM-G900V using Tapatalk

 

[Alan Tochterman]

My goal was to have longer flying times in order to create videos, once I master the art of flight. I figured that if I were careful, the T-Motors combined with the 9450 props would allow me to do just that if I were not too aggressive. I performed an advanced calibration and it helped tremendously. Then I adjusted the gain to 130% because I was experiencing, in my opinion, too much drift. Currently I was observing at about only 15 feet. I think at a higher altitude, it will be less noticeable to the human eye. The weather has been nice for the last few days. We go back into rain mode for three. After that, I will try again.

Thank you both for all your suggestions and assistance.

 

[TheDroid]

Just adding to this thread. I have 2 multistar 4000mah batteries and hooked up together I am getting around 18 to 22 min depending on weather conditions and how hard I fly her. I have a Garmin virb elite cam attached, a Sony FPV cam with a boscam TX and inside I have hooked up a DJI OSD and PMUV2. I have a phantom 1.1.1. Also I have tested each multistar batteries by flying each one solo and am getting about 13 to 14 min before she lands.