https://www.amazon.com/dp/B06XWBSLGL/ref=sspa_dk_detail_1?psc=1&pd_rd_i=B06XWBSLGL&pd_rd_wg=H2E9q&pd_rd_r=5KPHR5QAQ9AP3SP2KEG5&pd_rd_w=KvB81

https://www.youtube.com/watch?v=OjtXoScqDbU

led strips can typically be cut in specific places. Look for the correct mark. This is a 16 ft. strip and one accessory you can buy is connectors for separate sections. It's plugged in but that's the cheapest way.

You could look for a 5V led strip which is more easily battery powered, but still changing batteries every few hours at most.