Redflow pins post-Covid hopes on Gen 3 battery – and a market beyond lithium-ion, page-4

Catch 22 with size and capacity. to offer real back up and allow cell to be drained of energy and do recycle you need IMO 2 battery so you always have basically 50% of total capacity available if battery is required while one is on recycle mode. So 1 battery with 2 cells in it at same size or a double 7.5 for example?????

So for back up purpose design would generally require 2 or more batterys IMO but can be stacked vertically a swell if floorspace is limited .