Mavlink message for battery status

With BATTERY_STATUS message, ArduSub will send it with all necessary data.

Thanks. :smile: My bad I didn’t read properly

Please let me know if you need any further help.

Patrick, we are trying to read batter voltage with pymavlink. We parse the BATTERY_STATUS message and receive the following:

BATTERY_STATUS {id : 0, battery_function : 0, type : 0, temperature : 32767, voltages : [65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535], current_battery : 49, current_consumed : 4204, energy_consumed : -1, battery_remaining : 47}

The current measurement in centi-amps appears fairly accurate however, the array of voltage values doesn’t contain the measured voltage. We are using the latest version of the power monitor module.

Thanks in advance, Tim

You cannot read the individual cell voltages without a battery monitor that connects to each individual cell. We do not have any experience with this, if you do find one there may be some support issues with ArduSub.

@asjb Are you using ArduCopter or ArduPlane? If so, you will get some better help at discuss.ardupilot.org.

We simply want to read the battery voltage as it appears for example in qGroundControl, but using pymavlink. Please advise. Thanks.

Check SYS_STATUS.

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Thanks Jacob!

The current being drawn from the battery, measured in centi-amperes (like cm is centimetres).
100 cA = 1 A, just like 100 cm = 1 m. Conversely, 1 cA = 0.01 A.

The value displayed in current_bettey in the BATTERY_STATUS item is 380. So how is it calculated?

With a suitable power sensor (e.g. our Power Sense Module) the relevant calculation parameters can be configured in the Power Setup Page. The calculation that occurs depends on the type of sensor that’s connected.

What is the meaning of the current_battery value among the BATTERY_STATUS items? The unit is cA. How many amperes (A) is 1 cA?

I am using a sensor sold by Blue Robotics.

The current is calculated from a measured voltage that’s proportional to the current. From the product page:

I wonder what 380cA means.
If 100cA = 1A, is 380cA = 3.8A?
If 1cA is a discharge rate of 1 centimeter, assuming that the length of the power cable is 1m, is it 100cA?

Yes, that’s correct.

thank you.
Is it 380cA at 1cm and 38000cA at 100cm?

I’m not sure what you mean by this. The cm/cA idea was an analogy to describe the “centi” prefix. The current is not actually related to a distance.

380 cA = 3.8 A, and 38000 cA = 380 A, if that’s what you’re asking.

Thank you