Clicking noise from old Anker Astro E7 26,800 mah battery

First from main page where is the POST NEW MESSAGE button?

Is it normal to hear a click when plugging in an old 2016/2017 Astro E7 Anker 26,800 mah battery? I never noticed it before. I thought it was dead but bought a new cable to charge it which worked. But I hear a click when I plug it in. I never used the Astro much so maybe I didn’t notice it. It is not all the time. Just once.