If this reading is situated at 10 volts or below, your battery is presumably bad.
That's what scientists refer to as coffee. This small graph gives us an indication of the color of the light can be produced. You can put them on trees, small bushes, along your deck and gutters and such. https://Shikhadabas.com/2024/09/14/simple-lighting-tips-for-filmmakers-cheaply/