Battery voltage is dropping faster and the current flow is higher

Drone Specifications:- Using T Martin motor 330 kv, 1555 carbon fiber propeller, 40A Hobby wing ESC, Holybro Pixhawk 4, and lipo battery of two 10,000 mah (Genx ace battery)

  1. While flying a drone the problem occurs with the quick voltage drop and fast flow of current.
    When we have armed the drone and are ready to lift the drone voltage discharge very fast and current flow also increases as we have observed while flying and it is also indicated in the Tlogs and data flash logs.
    Example - 22.2V total battery voltage when the drone is lifted and it is airborne. The battery voltage will be 21.20V in one minute and the current (Amp) is reaching till 20,22 amp as we have observed while flying. The discharging of the battery is quicker.
    2.We have also observed as we are throttling the drone it is lifting stabile but the voltage is discharging faster and the current increases it is reaching till 20Amp and 18Amp as we can observe in Tlogs and Data logs.
    The timing when the problem start occurring is from 10:44:13.
    please help me to resolve this problem . The battery is getting quickly discharged and the current (amp) is going high so we are not getting good flight time.

tlog (983.1 KB)

Need the .bin log file not the tlog
It seems like the aircraft might be overweight for the combination of battery/motors/props - just guessing at this stage

This craft should not have left the ground. Old firmware on default parameters. At least start troubleshooting with a properly configured pre-tune craft. Update to latest Stable and use the Initial Parameter Setup in Mandatory Hardware to set these parameters.

What is the Take off weight of this craft with batteries?

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In that log the battery was 21.3 volts to start or just over 3.5 volts/cell. That’s way to low to be taking off. 3.5v/cell is the minimum voltage for a LiPo battery before you start doing damage to the cells. A fully charged 6S battery should be 25.2volts or 4.2 volts/cell. The voltage dropped off because you were flying with a discharged battery.

And follow @dkemxr Dave’s advice: Update your firmware and do the Mandatory hardware setup. If the firmware is that old, you may need to update Mission Planner to get all the latest features that will go along with it.

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Take off weight of the craft is 2.5 kg with batteries

We are using two 10,000 mah battery 25C, 11.1V of one battery. The maximum capacity charging of each cell is 3.7V. Total voltage of both the battery are 11.1V+11.1V= 22.2V.

Lipo batteries are at full charge at 4.2V/cell as @Allister said. You would be better off with one 6s battery charged properly.

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3.7v is the nominal voltage of the cell. Fully charged is 4.2, and minimum is 3.5. Two 10,000mah 3S or one 10,000mah 6S, same same. Either way, if only charge it to 3.7 v/cell then you are never going to get the performance you expect or paid for.

Here’s a good read:

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Hi Allister,
Could you help with the information that how you have developed this graph?

I used MavExplorer. It is a part of MavProxy.

Is it a LiPO or is it a Li-ION battery?

As Dave said, the Initial Parameters calculator will give you the correct settings to start with
These are key to your battery management - there is NO effective way to fly and guess about the battery voltages and current usage. This is one of the jobs of the flight controller.

These are the setting you will need
and if you cant arm and fly because of a battery warning, or failsafe occures sooner than you expected, then fix the actual problem (like voltage calibration or failing battery). It is a mistake to change or disable these values.


LiPo according to the OP.

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