It would be really nice to finally get an efficiency metric for the DJI FPV OSD. (I have the other metrics enabled.) Is this planned, or already in 4.2 (or 4.3 beta)? I checked the change logs and the closest thing I found was “DJI FPV OSD multi screen and stats support” which doesn’t seem to specifically mention it.
You need to install fpv-wtf on your DJI goggles to get this. fpv-wft
I’m now using wtfos. There is OSD1_EFF_EN, but for some reason, the implementation is mAh/km instead of wh/km. Clearly wh/km (or wh/mi) is superior. I don’t know what that dev was thinking…
Can you get a readout of remaining battery capacity in Watt-hours? If not, mAh/km might be more useful as a measure of how far you can get with remaining capacity.
I agree though, Wh/km would be ideal if we also tracked battery consumption and capacity in Wh. That way the decreasing voltage would be compensated for.
The point of mAh/km and wh/km is to test different speeds, motors, propeller setups, etc. to find out which is the most efficient, in real time.
It’s not about trying to figure out how far you can get with the remaining capacity, although that might be a minority sub-case use for it. If your battery is low you’re already going to fly at whatever speed you’ve already figured out ahead of time is more efficient.
The problem with mAh/km is if you convert your system from 4S to 6S, midway through a bunch of experiments, your original metrics aren’t correct and have to be converted so that they can be compared to the new metrics with the new higher pack voltage.
All true, but on the flip side if you make any major changes like convert from 4S to 6S then you will be starting over and retuning anyway.
Changing prop size or brand would be a good use case though.
Also imagine that you want to compare your best efficiency with others who are flying the same aircraft, but with different pack voltages. Now the mAh/m needs to be converted. Seems better all-around, for several reasons, to just use the standardized wh/km for real-time efficiency.