If you're ever inclined, lead acid batteries can be easy to repair and diagnose lifetime for - depending on the type. Sealed ones are harder but not impossible.

If you're ever inclined, lead acid batteries can be easy to repair and diagnose lifetime for - depending on the type. Sealed ones are harder but not impossible. Open ones take a little more maintenance but have long lifetimes and practically indestructible if you service them often. The most common cause of death is sulfate build-up, which can be prevented (and often reversed) with a homebrew circuit[1]. 1. https://batteryuniversity.com/learn/article/sulfation_and_how_to_prevent_it#:~:text=If%20a%20battery%20is%20serviced,block)%20for%20about%2024%20hours https://batteryuniversity.com/learn/article/sulfation_and_ho....