We have been using a solar suitcase for over 10 years but there are times when there is no sun and a small generator is needed for battery charging . We carry a 1000 watt Honda generator for charging and we have a inverter to power what we need that’s not 12 volt , its quiet and sips gas . We prefer the portable solar panels because you can move them around to get some sun if your rv is under the trees. We used to use two 2000 watt Honda generators In parallel for our last larger RV with supplemental solar use as well .