Less than what? If you're converting DC->AC->DC to step it up, why not just convert DC->AC next to the battery, then AC->DC or just use the AC directly like you would in a motor at the point of use?
Are you talking about skin effect losses? This isn't a long distance high current grid transmission system, for the lengths and sizes of conductors in a home (or RV), I think it's safe to disregard skin effect.
