My test was done with the power supply connected (no way the battery I have can last 7 hours!)
I have a 6V 5Ah Lead Acid: https://www.amazon.com/gp/product/B00MYL8OQU/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Got some copper sheet and made a 3d printed repro
I get 7 hours just running the After Dark screensaver all day as a test. And thats skipping through all of the battery low warnings til it finally shuts down.