When charging lipo batteries,do you let charger run until the charger automatically stops charging, or due you watch the meters an manually stop the charger as soon as 4.2 volts is reached.In other words can you over charge a battery with an auto charger which most are. Also asking because I have read that when charging batteries,you should stop charging when 4.2 volts is achieved. My chargers well show 4.2 volts but keep charging until it decides when charged.