Unread post MP Voltage not dropping as battery voltage drops

Hi all.

I have a Quanum Nova with Mini APM 2.5.2.

I am trying to get a reliable voltage signal to appear in Mission Planner (and in my Minimosd).

In Battery Monitor, I’ve selected:-
Monitor - 3, Battery Volts
Sensor - 0, Other
APM Ver - 1, APM2 - 2.5 non 3DR

However, when I adjust the calibration to create an accurate voltage output reading, the value basically doesn’t change. It fluctuates by +/- 0.1v but as the voltage slowly decays (as it’s powering the minimosd, gimbal, video TX etc) the voltage in Mission Planner doesn’t.

Even after a flight when the battery has gone from 12.3v to 10.8v, mission planner still shows 12.3v.

Do I need to buy a separate device to be able to get accurate voltage readings? I thought I’d be able to get a simple voltage output from the APM without any extra device…


What APM power module do you have? I assume you have one and it’s connected correctly? Details in the manual which you can find here: rcgroups.com/forums/attachme … id=6623645

Ah, just seen your reply. I’m not running any power module. My Quanum Nova is stock apart from the MinimOSD.

I thought that as the Nova is obviously measuring voltage itself (as it does alert when battery voltage drops too low) that it can also send out that info via MAVlink to Mission Planner and the MinimOSD. Is this not a correct assumption?


PS. Switched on e-mail notification :unamused:

Sorry, I don’t know what’s provided in the Quanum Nova - in fact I just had to Google to see what a Quanum Nova is! As you’re running Mini APM FC, then you will need a Power module to send the analog voltage and current data to the correct pins on the power connector of the FC. These feeds are 3.3v based. You then calibrate this under Initial Setup, Optional Hardware, Battery Monitor, section in mission planner - think you found that page already. If you are seeing a voltage reading in MP now, its likely the flight controller voltage rather than the flight battery voltage. Is it around 5v by any chance? Of course the Quanum Nova may have its own power module that I’m not aware of, and this could already be implemented but by the sound of your results of trying to calibrate, it sounds like this might not be the case. For more info about the Power Module, see here: http://ardupilot.org/copter/docs/common-powermodule-landingpage.html

The power module is quite useful as it not only allows you to monitor your battery voltage and current, but also ties into the Battery Failsafe function.

Thanks Paul,

I’ve ended up buying a 3DR Power Module (all-be-it a clone as I couldn’t find a 3DR one in stock anywhere in the UK). I now have full volts and current readouts.

The voltage I WAS seeing was around 12v, but not changing which was very odd. Anyway, all sorted now, and thanks for taking the time to help.