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_ho....