Our charger/inverter is at least 11 years old and has been mounted in the lazerette and still going strong. A few months ago I did notice that the A/C leads attached to the inverter were corroded and re-stripped and mounted them. Interior would be optimal but if the only reasonable place is the lazarette then that will do. Our lazarette is huge and pretty well protected against salt water, though we are in the hot and humid SoFla climate.