While you're searching for batteries (or any other potentially smart appliance), check if they are supported by just searching for "device home assistant"
Those that have official support will have a page on home-assistant.io and scrolling the description will tell you if it's controlled locally (preferred) or via cloud polling/API (less preferred)
Some devices may have custom integrations you can setup from Github via HACS, where the quality and support can vary more significantly than official integrations.