Four AAA batteries.
Your Wyze Scale batteries should last 6+ months. But if you need to replace the batteries, you can do so in the scale's back panel.
We are currently experiencing an issue where devices may not successfully pair with the Wyze app. Our team is aware and looking into it. Thank you for your patience while we work to get this resolved. Feel free to keep an eye out for updates https://support.wyze.com/hc/en-us/articles/360015979872-Service-Status-Known-Issues
Your Wyze Scale batteries should last 6+ months. But if you need to replace the batteries, you can do so in the scale's back panel.