Multiple Battery Monitors: SumOfFollowing Command for BATT_MONITOR?

Hello, I have two separate batteries and two separate current sensors and I would like to combine the Mah and amperage that is used during the flight so that it only appears as one battery. I see on some threads that the “SumOfFollowing” command could be used, but no documentation on this. Can someone please describe the “SumOfFollowing” setting in more detail as an option for BATT_MONITOR?

Or if this is not the correct way to report it, any help with the setup parameters would be great.

Any help would be greatly appreciated.


Basically as you described it. Set the first monitor to Sum, then configure the next two for your actual sensors, and it will be reported as a single battery.

Awesome, thanks for the quick reply James. That is the only setup I did not try yet- Will give it a shot!


That did it, thanks for the assistance.

Just to confirm, in this setup, would you leave the first Battery Monitor (BAT_AMP_PERVLT) at 0? So basically Bat1 just contains “SumOfFollowing” and no other parameters? Then Batt2 would take the place of Battery 1 and Batt3 would take the place of Battery 2?

Yes. The sum just does math on those following it (ie adds current, averages voltage). The actual sensors still need to be set up as per normal, as garbage in = garbage out (as you know).

Got it! In that case I assume Battery mAh should be left blank as well and we just do everything through Batt2 and Batt3?

Much appreciated!

Also curious for some clarification on this since I can’t seem to find it in the documentation - If the first monitor is set to be the sum of 2 and 3 (BATT_MONITOR=10), does BATTx_LOW_MAH get set for the first monitor? Same with BATTx_FS_LOW_ACT?
And on monitors 2 and 3 you only set the _CURR/VOLT_PIN params?

As well I assume BATT_CAPACITY gets set and BATT2/3_CAPACITY are ignored? =0?

Recently I started using some of following And I’m not sure it is implemented correctly or fully.

I would also appreciate if someone who knows what is supposed to happen can explain how exactly it’s supposed to be used and what behavior to expect.