There are many options for a battery. A junior member made a 4 D cell battery holder from a piece of PVC tubing and 2 end caps. I use a 6 volt emergency lighting battery. I use this brand. Get them from eBay. The black ones are cheaper but the ones Ive had didn’t last more than 2 years. Playing around, I got a folding Lightweight (this model is similar to yours having many of the same parts) to run on a little 9 volt battery. https://www.youtube.com/watch?v=PotK2rSrJC0
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.
