I really need an accurate battery monitor but so far I have not been successful.
I am using a Cube Orange as flight controller. 12S batteries. Two Mauch BEC’s. One 025 and the other 021. I connected one to Power 1 and the other to Power 2. One cable has the voltage and current sensor and the other cable only has positive and negative wires.
I set battery monitor 1 in Mission Planner. I set the sensor as “Other” and HW as Cube Orange. Since I do not know the voltage divider I measured the voltage on the battery, plugged it in and change the battery voltage in battery setup manually.
The voltage on screen will show the voltage ok
However every time I plugged in the battery to fly I get a different voltage. Sometimes low and sometimes high.
The last flight the voltage was high. I landed and QGround Control on the Herelink handset reported over 49V but the actual battery voltage was something like 46.7V.
It is a constant struggle to establish a stable and more accurate voltage.
Is there any work around. I tried all kinds of trouble shoots. I swapped the power cables around between Power 1 and 2. I swapped the power source between the 025 and 021 Mauch BEC. No luck.
I appreciate any help anyone can give me. I am running Arducopter 4.6.0 firmware on the Cube Orange. Please ask if you need more information about the setup.
It is probably best that you supply a diagram of how you have these connected, or at least how you expect it all to connect up.
The 021 does not have a built in current or voltage sensor, so if it’s connected directly to PowerA or PowerB sockets it will not report voltage or current and you would have to set BATT2_MONITOR,0 (disabled). The internal hardware of the Cube will still make use of the backup power, the voltage just wont be logged. The status is still reported in Power.Flags
If you connect it to an external voltage and current sensor it can provide that feedback with BATT2_MONITOR,4
The 025 already has two backup BECS like the 021 on connectors 1 and 3. The output you would normally use is connector 2 to PowerA.
You still need to attach an external voltage and current monitor like a PL200 via connector “S”
What you are seeing reported as a voltage is probably just floating voltages on the voltage sense pins of the Cube. Since they are high input impedance they will pick up some of the 5v from the adjacent pins.
Thank you Shawn I believe you have hit the issue on the head. I emailed Christian Mauch and he concurred that I need a separate voltage and sensor like the Mauch PL002 to monitor the voltage and current data. I was just assuming the Mauch 025 or 021 BECs have voltage and current sensor built in. I ordered the Mauch sensor so I should be able to see if I can get better battery voltage information on the ground station.
Just for clarity, I was a bit wrong there - the Vcc is logged (5 volts from the BEC) but the battery voltage is not available the way you had all that gear connected.