Multiple battery monitoring - combine amperages?

Have seen BATT2 emerging in APM 3.3 - which is very welcome, but everything I have spotted so far points to two completely independent monitors.

Two independent voltage monitors is fine for me, one to monitor the flight power source and one to monitor the avionics battery. I’m not really worried about monitoring the avionics current, but I would like to combine the BATT and BATT2 amperage to help monitor the flight power.

My flight power is two 6S packs, each (for resilience) wired to the power distribution board. I appreciate if I used a ‘Y’ lead I could use one ATTOpilot sensor; but I have two separate leads, each with their own in-line sensor, soldered to the power board, one per pack.

As the packs as paralleled up, the voltage will be common. The separate currents, if logged/monitored, may give an extra indication if one battery is mismatched or running down faster than the other, so two independent mAH figures are useful.

The reason for the question is my concern is that, for those who run parallel batteries in maximum resilience configuration, unless the two amperages can be summed in real time, COMPASS_MOT cannot be used.

Are there any plans to add any summing capability?

Dave Martin

As you say, the two monitors are very different and only one of them is used for failsafes, compass-mot, and battery voltage compensation.
I’m afraid we won’t be able to make this enhancement in Copter-3.3. If you could raise an issue in the issues list then that would probably be best.