Servers by jDrones

Fast draining of battery


(Ashwani gupta) #22

How about the pattern of discharge?
As you have seen that it is showing a sudden fall when armed?

(Hari .P) #23

First balance charge the battery.
Set FS or alarm to 3.5 Volts.
Make a flight. Download that log. Look for volts, Curr, Curr Tot…etc OR post the logs here, so that the experts can comment.
Recharge the battery after a resting period of 1/2 an hour and note how much mah you can put in.
P. S.-Pls check the resistance of the cells.

(Ashwani gupta) #24

so please suggest that my charger (vista ap 606,max charge current is 6 Amps), will be enough to charge my power pack which is a TATTU, 4S1P, 10000mAH.

(Hari .P) #25

it will charge.
have you checked the resistance of the battery…?

(Ashwani gupta) #26

ok i will check. do we need to have a watt meter for calculating the internal resistance ?

(Hari .P) #27

Read Charger’s user Manual.
I doubt that charger can read battery resistance !..

(Mike Boland) #28

Once your battery is charged its charged, doesn’t matter how slowly you charge it.

After your flight how many mAh do you put back in?

(Ashwani gupta) #29

After every flight I used to fully discharge and then charge it again in balance mode fully next day.

(Christian Labeck) #30


What I did at the beginning to get a feeling about battery and power consumption was to:

  • write down after each flight (from the logs) the total mah used during flight (curr tot i believe).
  • write down after each charging of the battery (from the charger screen) the mah that were charged into the battery

If everything is right then both numbers, mah total used from flight log and mah charged from charger should be roughly the same, maybe +/- 5% max.

If the numbers mismatch root cause could be your charger setting, or your current sensor calibration.

Also, what is the C-rating of your battery?


(Jagger) #31

That’s probably damaged the battery.LiPos don’t like being drained totally.

It would be useful to have a charger with internal resistance measurement as it’s the best health check available cheaply.

(Hari .P) #32

Can you please explain it . How?

(OldGazer) #33

I’ve seen this before. The propulsion system (motors and props) is all wrong.

For that kind of weight you need lower Kv motors and bigger props.

I have a Tarot 680 Pro with an AUW (All Up Weight) of 3248 grams. I’m using 4006-740Kv motors swinging 1355 carbon fiber props. Battery is 2 Tattu 5200mAh 15C LiPos in parallel. Hover current is 27 Amps, or 4.5 Amps per motor. Flight time is a tad over 20 minutes using 80% or 8320mAh of the battery capacity.

I looked at your log and your hover throttle is TWICE what mine is.

Here are a couple of hints…

First off, when you are shopping for motors, you CANNOT use maximum motor/prop thrust. Typically, motors that list just their maximum are for AIRPANES. To find motors that are suitable for use on a multirotor aircraft what you should be looking for are motors that have the thrust you need at or just below 50% throttle. In your case what you need is a motor/prop combination that will make AT LEAST 716 grams of thrust at 50% throttle.

Second, the reason your battery is discharging so quickly is the motors are running at or very close to full throttle just to get the aircraft off of the ground. In this situation the flight controller has no throttle left for maintaining stability and crashing is very likely.

Third, at this kind of weight a hexacopter frame under 700mm is just too small. FWIW, Tarot rates the 680 Pro for a MAXIMUM AUW of 3.5 Kilos with a maximum prop length of 13"…

(Ashwani gupta) #34

not fully discharge, but discharged by using proper charger upto a safe limit.

(Hari .P) #35

Post details of the motor.
details of the frame

(Ashwani gupta) #36

avionics C2830 850 kv

(Ashwani gupta) #37

sir there was a problem in my power module, which is giving me wrong result and applying fail safe in early stage of voltage. i just change the power module and fly my hexa. As you are assisting with your valuable suggestions, i am sharing my flight log with you. please have a look and comment.

(Hari .P) #38

I think you removed some weight. Good.
No GPS? Magnetic interference high.
vibrations are also on the high side.

(Ashwani gupta) #39

no , i didn’t removed single gram of weight. GPS was there but a bit late. Yes magnetic interference is high i am accepting.

(Hari .P) #40

do you have a quad?..

(Ashwani gupta) #41

Ya i do have two quad. One sports and one standard frame