I recently bought a Phoenix 48-250 inverter. When I plug in my wife's c-pap, the led lights blink and when I look at the output voltage on VE.Direct, it is jumping all over the place. I am not overloading it. It just doesn't like the c-pap. The c-pap has a transformer that changes from 120v ac 1.4amps to 12.8dc 4.5 amps. Any suggestions?