As one who has owned Phantoms (2012) and Inspire 1 Pros (2015) I'm used to obsessive battery maintenance following the recommendations of DJI and Airdata. But with the M2P it looks tricky. I don't have a discharge tool for the batteries, (50% when not in use). I do check for cracks and bulges every time I use them. But my batteries are all getting close to 200 uses and over 20 hrs. The full service recommendation includes cleaning the terminals but they are quite delicate contacts and its not possible to see if they are stained. Anyone have a suggestion how to safely clean the contacts?