I recently purchased a P3A and began looking into charging multiple batteries at the same time. I've seen several places selling what looks like a PCB board with three charging areas and a fourth port for the wall charger to plug into. Curious if anyone knows how safe they are to use or have tried them. I know the manual says you shouldn't charge a battery and the remote at the same time so trying to charge three batteries at the same time seems unsafe. I also found DJI is selling a charging hub where you can connect four batteries into it. Anyone try it? I think I read some where that it only charges one battery at a time and moves on to the next.