I get questioned about this often. Here are answers straight from Apple.
”Battery life” is the amount of time your device runs before it needs to be recharged. “Battery lifespan” is the amount of time your battery lasts until it needs to be replaced. Maximize both and you’ll get the most out of your Apple devices, no matter which ones you own.
Not that this will necessarily solve all of your battery ilks, but it pays to give them a whirl.