Wall batteries and rack batteries can use similar cells and similar voltage platforms, but the customer experience is different.
Wall units are easier to present in residential sales. Rack batteries are easier to standardize for telecom, small commercial and distributor stock.
Wall batteries are tidy and homeowner-friendly
They fit garages, utility rooms and small homes where the visual result matters. They are also easier to package as a simple residential storage offer.
Rack batteries are better for controlled expansion
Rack systems make it easier to add modules, label units and replace a battery later. For repeated project work, this can matter more than appearance.