Not enough power when below 45% battery

[drjay32]

I started having what I thought was power loss issues last week with my Phantom Vision. I've since tested and found that my bird won't ascend once the battery is below 45% or so.

Here's what happens when I try to fly with the battery at 30%:
[youtube]http://youtu.be/2Y4TSso5tNw[/youtube]

This happens with three different batteries. I get cell voltages around 3700mV when they are low, and 4100mV when full. All cells are within a few mV of each other. I've cleaned battery contacts and the internal contacts in the Vision with DeOxit.

Any thoughts? Performance is fine with a full charge.

-Jason

 

[Ozzyguy]

Have you tried cycling the battery by giving it a good discharge and then recharge. Down to about 10% then a full recharge.
Also you seem to have 2 cameras on? What is the total weight?

 

[drjay32]

Have you tried cycling the battery by giving it a good discharge and then recharge. Down to about 10% then a full recharge.
Also you seem to have 2 cameras on? What is the total weight?

This happens with all three of my practically new batteries. I'm running the stock Vision camera with a Rotorpixel gimbal.

 

[sar104]

Have you tried cycling the battery by giving it a good discharge and then recharge. Down to about 10% then a full recharge.
Also you seem to have 2 cameras on? What is the total weight?

This happens with all three of my practically new batteries. I'm running the stock Vision camera with a Rotorpixel gimbal.

It really would help to know the weight of that setup.

 

[wkf94025]

I am seeing very similar behavior with all 4 batteries across older P2 and newer P2. i suspect firmware changes.

Kelly

 

[EMCSQUAR]

Have you tried cycling the battery by giving it a good discharge and then recharge. Down to about 10% then a full recharge.
Also you seem to have 2 cameras on? What is the total weight?

I'm w/Oz here, I'm betting your Phantom is overloaded weight wise. What does it actually weigh fully loaded as in picture and what are your battery warning levels set at? Actual weight not a guess. I'm betting it's well over 1500 grams. If so, she needs to go on a diet. That's the same behavior my Kong Copter does when I put on a 3S 5000mah battery. When I put on a 4S 5000mah battery it flys much longer. And NO DJI or anyone else does not offer a 4S "smart battery" (yet)

 

[drjay32]

Thanks for the feedback, guys. This is a stock Phantom 2 Vision with a Rotorpixel Gimbal. No other mods. The gimbal was designed for the P2V, and while it is heavier than stock, it shouldn't be causing this problem.

Moreover, when I rev the throttle at these battery percentages, it's as if nothing happens. The motors don't spool up. It's not like the Phantom is straining against the weight, it's just not producing thrust.

-Jason

 

[drjay32]

Update

Ok, today I tested the unit with the gimbal and camera attached, but I disconnected the gimbal power cable.
I was able to fly and take off even at 12% power. When I reattached gimbal power, I couldn't take off.

This tells me that something in my gimbal was drawing too much voltage. Keri at Rotorpixel is shipping me a replacement and was SUPER RESPONSIVE to my email message, replying within minutes.

Thanks for listening!

-Jason

 

[wkf94025]

Fascinating. I will run similar experiments with my P2+H3-3D. Wouldn't have thought to try that.

Kelly