The battery is a low level product in both Assembly Line 1 and Assembly Line 2. They are generally not built to sell directly except for early to mid game and are instead used as a component in later stage items.
Batteries in Assembly Line 1[]
Battery Recipe in AL1
Batteries are further in the production chain than Circuits and Engines (as opposed to AL2 where these components are effectively equal). They are composed of 1 Circuit, 1 Raw Aluminum, and 1 Liquid Aluminum. They are used in various finished products, most notably Drones and Electric Generators. Batteries have a better profit per raw material used (at $208.33) than many early game finished products such as Air Conditioners, Toasters, and Washing Machines (at $175, $175, and $152.14 respectively).
Drones have the best profit per raw ($569, over 2.7x as profitable as selling batteries directly) before AI Robot components and one third of their 30 raw materials are used for their batteries.
Batteries in Assembly Line 2[]
Batteries are low tier items created in a Crafter MK1. They are composed of a 1 Raw Copper and 1 Liquid Copper. They are used as components in Electric Engines and Lasers on the AI Robot technology tree as well as the Ignition System on the AI Robot Bomber technology tree.