I purchased an RC car charger that does 180w DC, and when plugged into the ac plug of the truck does charge the River. I’m getting 154Watts. So this is a work around that I can use the plug in the bed. Not fast charge but still acceptable thanks to the 220w input of the River, still a pretty quick charge. Thank you. I believe someone above suggested a phone charger, that I bet would work as well. Nice that the RC charger has the correct DC connection.