BATTERY FADE

[RunnerDuck]

I've been reading a lot of stuff on the forums about batteries but there's something funny going on with my quad.

It takes off fine and flies great for about 1:30 minutes then starts to lose power. Once I get it safely on the ground I check the voltage and I still have around 12.1 - 12.3. The best I've ever done, but this was only my fifth flight with it, was 2:40 minutes.

Here's what I'm running:
Turnigy HAL Quad
NAZA-M Lite MC
Taranis X8R Receiver
FrSky FLV SS LiPo Voltage Sensor
HK Power Distribution Board
HK Lipoly Low Voltage Alarm
SkyZone 5.8 Ghz 8 Channel Transmitter
Tarot 2D Gimbal
Turnigy D2830/11 1000KV
Tyrnigy Plush 30A ESC
Zippy 4000 mAh 3S 25C LiPo Pack
600 mAh 2S Lipo for FPV/Gimbal
10” X 4.5” Props
4 Pounds 9 ½ Ounces
Taranis X9D Plus Transmitter
SkyZone RC805 5.8 Ghz 8 Channel Receiver
ReadyMadeRC 8” LCD FPV Monitor
Zippy 4000 mAh 3S 25C LiPo Pack for Monitor
600 mAh 2S Lipo for FPV/Gimbal for Receiver

I run the gimbal and FPV transmitter of a separate battery.

Any idea as to what's going on and what I should do?

Thanks,

Ken

 

[Old Man]

Look closely at your low voltage alarm settings with the understanding the battery under load voltage readings will be lower than no load. Also put a volt and amp meter, I like the Watts Up but others doing the same thing are out there, in line with the battery during a weighted ground run that prohibits lift off to see what kind of current is being pulled by the system under load. verify battery state of charge before initiating the above. Once you have a bit more foundation info the serious problem resolution can start.

 

[RunnerDuck]

Thanks Old Man, I've ordered a Watts Up and it will be here Tuesday.

I'm still curious though if there is anything in my list that looks out of whack for the way it's acting?

Thanks,

Ken

 

[Old Man]

The battery sizing is a bit low from my perspective. Lower voltages consume more amps so I might be looking more towards a 4s battery. The 10x4.5 props seem a bit large for the motor kV. Those props would usually be found on motors closer to the 850 to 900kV range. Without knowing what your voltage failsafes actually are I could not say they were too high or too low. You didn't mention if your motors and ESC's seem to be running hot or not. A bunch of little stuff, but it's all stuff that might add up to something larger.