I am in the process of building a new hexacopter powered by pixhawk 4 which is likely to fly sensors costing several ten's of thousands and I want to improve power delivery. I wanted to know your experiences with multiple batteries on the drone.
So far I have only used a single battery at any time but I know people that use multiple batteries on large crafts as it gives better COG when using different payloads configs and they don't have battery status available other than buzzer/timed flying.
Please look at the attached file showing options and give your opinion.
Essentially in option 1, as far as the system is concerned, there is only only physical battery with a larger capacity.
In option 2 the system is aware of presence of multiple batteries and is able to monitor consumption out of each. Although it can not be scaled as it is dependant on the availability of ADC channels but provides power pathway redundancy.
Pixhawk 4 specifically has 2 power ports. Each power port has its own ADC channels for voltage and current so it is capable of monitoring two batteries at once. But if using the supplied PM07 module, you are only monitoring one physical battery and the other power port is acting as a redundant voltage and current sensing since the PM07 only has one sense resistor and two op-amps for current.