Red battery voltage in HUD

The battery voltage is red in HUD although it’s high enough.
Shouldn’t it be white ?
Is it a bug ?

MP 1.3.73
ArduCopter 4.0.3
4.0.3-20200904.param (19.9 KB)

You can set warning levels here

It is somehow tied to speech warnings, but once you set you can switch off the speech.
Default values are 9.6 volts and 20% capacity remaining.

thank you for your reply.
I have configured the battery monitor and arming check, see parameters.
The copter can be armed, the battery isn’t low.
So the question is why does MP warn ?

Missionplanner is doing the same thing to me and my parameters are correct. Started with MP 1.3.73.

Did you guys misses the red circle ? Check it and set the warning levels.
MP_ HUD red battery warning is independent from the FC settings.

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Even with warning levels set I’m still having the same issue

Look for these two lines in Documents/Mission Planner/config.xml


Are they there ? (Values may be different)

No, they aren’t there.
The “MP Alert on Low Battery” is switched off.

I can turn HUD Bat into white if I edit the PreFlight check values:

and disconnect and reconnect.

This is a bit confusing since this is a “per MP config”, not a “per UAV config”.
I have UAVs with 2S, 3S and 6S.
So which battery level shall I configure ?

You have to switch the check box on, it will present dialog boxes to set the values.

that is even more confusing.
You have to enable audible warnings to configure visible warnings ?
Also the batt voltage seems to be the same as under “Preflight-Edit”.

Ok, I concur, it is quite confusing. I added a pull request which change this behavior to honor BATT_LOW_ and BATT_CRT_ parameters. I hope @Michael_Oborne will merge it soon and it could be included in the next beta.

Great, thank you very much !

Hi, I am using MP 1.3.75 and Pixhawk 2.4.8.
I am a first time rover user (boat) just before my first autonomous journey.

Running into the same problem, the red voltage in HUD.
running into the same problem.

I have calibrated Voltage and also checked MP Alert on Low Battery … unfortunately the red colour does not disappear. Did not yet check the preflight check list editor… Quite challenging

Found it now, set it to show red when < 9,6V.

Result: It is green now in the preflight checklist with 12,23V, but is still red in the HUD with 12,2V.
What do I have to do to get it white as well?

HUD battery value color is based on BATT_LOW and BATT_CRIT settings.
If these settings are not set, then it falls back to settings in speech warning values. Which can be set by enable speech and battery warning (it will ask for warning values). But if you read back a little, it was already said.

I had read the earlier mails and had checked the box for speech MP warning values to standard 9,6V and 20% capacity before I posted my message. BATT_LW and BATT_CRIT were/are set to 0. HUD still showed RED with voltage even greater than 12V. Yesterday I upgraded Rover to 4.1.1., set the MP speech warning value to 7,2 and afterwards back to 9,6V again. Now it fortunately works, but I do not see what I did differently. If I want to see which levels are set I have to look into config.xml as desribed above. Is there a way to see the set warning levels in Mission Planner directly? Could not find that.

And what about BATT_CAPACITY and CRIT_MAH and WARN_MAH ?

Battery display warning works the following way in Mission Planner.

There are three colors that the battery voltage and percentage can show.

White – All OK

Yellow – Warning

Red – Critical

The first thing checked is the BAT_LOW_VOLT BAT_LOW_MAH and BATT_CAPACITY

If battery voltage is below BAT_LOW_VOLT or the battery_remaining capacity (calculated onboard) is less than BAT_LOW_MAH, battery values will be displayed Yellow.

If battery voltage below BAT_CRIT_VOLT or remaining capacity is less than BAT_CRT_MAH, values are displayed in RED.

If none of the above parameters are set, then coloring is based on speech_battery_volt and speech_battery_percent, which can be set by enabling speech and battery warning.

If you do not set the BATTERY_CAPACITY parameter onboard, the remaining capacity will always be 0%, which means a red display.