Inverters and Electrics on a Small Boat.


I bought a new inverter for the boat, a sign perhaps of my change in function for Sadaf, not the ocean traveler i thought i was, but more of the stay at home kind and snuggled up in a warm bunk with a few home comforts. I bought a 500w 12v inverter to charge up my rechargeable batteries for my radio and mp3 player, and to recharge the computer; I have 3 car batteries and a solar panel which used to be for an electric motor.
The worst thing about the inverter is the noise from the fan, not comfortable. When everything is plugged in the wires are everywhere, and when i recharged the computer battery it must have taken a lot of power as the inverter shut down as the battery got near to the empty mark! I think it would be ok for emergencies but as a thing if relaxation and leisure it did not pass the test. 
I think I will stay with my rechargeable batteries and my speakers, there is no much volume (no amp with them) but it does OK if, like today, it is raining heavy.