So I got all new coach batteries and when I turn on charger it hums for a few seconds and stops humming and makes a clunk sound. Charging light stays solid at 12 volts, inverter light blinks and battery indicator stays solid red. I disconnected shore power, shut off 12v breakers and all breakers and let coach sit for several hours. Came back connected shore power and turned on 12v panel and 120v breakers. This time charger hummed longer but eventually made a clunk sound. Same result ie., charger solid green, inverter blinking, battery condition side red. I called Xantrex and they could not help. When I turn charger off, inverter blinks and battery condition goes from red to normal. Batteries all tested fine. No overtemp or overchargewarnings. Anyone had same problem. I miss the nice steady hum. Thanks