The thought of a dead battery in the middle of the lake doesn't thrill me. Perhaps the fear is irrational but the solar panel seemed to be a simple way to eliminate that fear.

9/25/2019 Update - I had not been on the boat for 4-5days and today the "Charge Light" had turned GREEN. So I guess it can fully charge the battery.

Here's a link to the panel on Amazon.
https://www.amazon.com/Battery-Tender...