The Project „ABBY“ (Air Breathing Battery) was launched in 2012 with the aim to develop an electrical energy storage system, being cost competitive, durable and light weighted. The used materials should not be toxic and ECO-friendly. It should also be a very safe electrical storage system: not flame able and without explosion hazard, which is a critical issue with lithium-ion batteries. The deployment scenario are smart grid (e.g. stabilization) and fully autarkic system for private households. As a result, the concept of an electrical energy storage system ABBY is created, based on “air breathing zinc batteries”. Integrating all the features required from a green energy management system of the future: energy supply at day & night. The patented (2016, pending) electrical energy storage technology is scalable, and available in application dependent energy storage demand: e.g. ABBY-1000 and ABBY-MEGA.