The idea of solar units is to keep the battery topped up because of constant draw of things like the clock, remote controls and such if the vehicle is just setting still and doesn't get run much. Power seats and chair lifts generally take a lot more power than those items. Now if the idea is to keep the battery topped up while the van is parked between uses and you just want to be able to roll up, open the door, use the lift, then start the engine and drive around. The solar units would handle that. If on the other hand you are thinking of being able to use the lift and seat on a daily basis but without running the engine, they won't work very well. For that you would probably want to do like many RVers do and put a few hundred watt solar panels on the roof and add a couple other batteries to handle the current draw.
5 watts isn't a problem, neither would the 17-watt panel for simply keeping the battery up while it's parked.
Thursday, January 6th, 2022 AT 7:12 PM