Does anyone know whether the 3 unit battery charger that comes in the fly pack kit, actually charge 3 batteries simultaneously? I put three bats in the charger but only two at any one time showed LED activity, the third showing no LED activity. If I removed one bat then the third Bat acted like it was charging. It seemed like the third battery only started charging when one of the other two were fully charged. Anyone else experience this effect when using the DJI 3 bat charger that come in the kit?