LG had some phones like that in 2016ish, on the G5 the entire bottom of the phone slid out to reveal a big battery slot and on the V20 there was a button that let the metal back of the phone pop off so you could change the battery. I had an external battery charger and a couple of spare batteries for my V20, so I could just pack spare batteries and swap them whenever it got low. I never even bothered to plug my phone in, it was always just faster to pop in a battery that was already fully charged. It didn't have any water resistance, but it was a pretty small price to pay for endless battery life

It's a shame that LG's whole phone division went under, because they were making some of the coolest phones that came out that whole decade