Vicky & Bob, We just completed the installation of a Trace inverter (3KW) on Sea Flat. We have it supported by 3 pairs of golf car batteries. We found that 8D's just do not last as long (life) as the GC's. And as an added bonus 6 GC's will fit in the same battery cases as the pair of 8D's, giving us about 200AH more capacity. Our inververter system is fully stand alone, dedicated batteries & dedicated alternator (150AMP). There is a diagram of the system on our website 'www.seaflat.com'. Click on the about button, and on that frame there is a hyperlink that will take you to 'equipment installed'. Cheers, Anne & Henri m/v Sea Flat