In order to rename any bot, you need to build for it a Name Badge on the Basic Workbench using one Plank. While having the Name Badge in the Farmer-Player's hands or inventory, you then select that bot, click on the "Trade" option, and put the Name Badge into the bot's "Upgrades" area. Once the bot has a Name Badge, you can click on its Name (such as "CB005") and then type a name for it of up to 10 characters (such as "RECHARGE01").