Second battery monitoring

Hi guys,
For VTOLs like quadplanes, sometimes it is beneficial to have 2 types of batteries:

  • Li-Po for hovering because of high discharge current
  • Li-Ion for cruising because of high power density

To my best knowledge, PX4 currently only monitors voltage of 1 battery and QGC also only shows 1 voltage reading. Most of the time, we monitor the cruising battery and guess the voltage of hovering battery.
I think it is beneficial to monitor both batteries as industrial VTOLs are likely to need both.

I know it can be done because APM and MissionPlanner have already successfully implemented this feature. I have tried on Pixhawk2.1 Combo board, which has 2 power ports, the usage is very intuitive.

If someone is already working on this, could you please give some comments?
Otherwise, if there is really nobody working on this, I would like to give it a try. So if you have some idea on which part of the code is relevant to implement this feature, please comment?

Have a nice day, guys!

1 Like

Hello ,Do you know how second battery monitoring ?

This idea seems interesting, even for emergency packs, or multiple same cell batteries (for extended or continuous flights). I wonder how to manage the high-current and high-speed switching between batteries, Some good MOSFETs could work but it will require a couple of tests before a real safe deployment in a UAV.

Looking for the same stuff, since months,
in my case for distinguish photovoltaic production from the propulsion consumption, difference would give part of the battery state…

Today QGC(V4.2.3) well monitor dual voltages and currents but onboard, only the first active is send to frsky_telemetry (PX4 1.13.0)