Are you sure the heat was on the right side? I have just taken mine apart and the battery is on the left side, connected through a wire to the other side (with charging port and all the controls on it). You could check the battery by taking off the left earcup. Underneath there will be 4 Philips 0 screws, after unscrewing them you can gently lift up the speaker and underneath there should be the battery. Be careful, while the cable is long enough to open them up safely, it still is quite short.