I bought a imax rc b4 compact charger. I have three lipo batteries. I tried to charge but it won't work. All the connections are made according to the manual. The charger loads up according to the manual and gives four green lights saying it is ready to charge. I connect the lipo battery it gives three red lights because it is a 3s lipo. And it should charge within half an hour or at max one hour. It has been three hours and it doesn't charge. Used the voltage checker and there is no difference in the voltage at all! Help much appreciated.