I met a guy in at Rancho Jurupa Regional Park that uses PowerMaster (
http://rvperformanceproducts.com/voltagecontrol.htm). They are external, and plug into the CG pedestal. They will protect against surges, they will boost low voltage up to 12%. I"m not sure about reverse polarity issues though. I'll have to check. I think I more interested, now, in Tom's setup. Tom, what was your source other than direct from Progressive Industries?