Replacement TI Rechargeable Battery for the Ti-84 Plus CE Graphing Calculator After several years, the battery in your Ti-84 Plus CE may not be holding up like it used too. Bring that number cruncher back into shape with a brand new TI Rechargeable Battery for the Ti-84 Plus CE. It's super simple to replace. We recommend doing so with the help of a parent or guardian. Please note: This battery is not compatible with the Ti-84 Plus C Silver Edition Graphing Calculators. Not sure which battery you need? Read this blog post.