Hi! My husband and I are working on converting our small truck to a camper. We want to add an rv air conditioner on top. We want to utilize ship to shore capabilities and will hook up to shore power when available. However, if we are off grid, we want to make sure we can at least run the AC fan for air circulation. Is it possible to run the fan off 12v? Also does anyone have a good AC suggestion in the $550 price range? Thanks in advance!!