Considering these copter fly for about 8 minutes on a full charge anyway, I run the copter until it begins to lose power and unable to hover - there is no LED notifier on the MCX2. You are right, the charger does not tell me if the battery is good or not - in fact, the 2 batteries that no longer hold a charge still act like they are being charged - and the charger blinks (within minutes) and then stops as if the batteries are fully charged (just like the good batteries). Am I correct in thinking that this e-flite charger stops charging when it senses the battery is fully charged (hence the blinking light)? If so, leaving a battery plugged into it for long periods of time (days) after it is already charged would not negatively affect the battery? Thanks!