The catalogue's 19 inch rack format batteries: Deye BOS-A modules of 7.68 kWh at 38.4V and BOS-G-Pack5.1 and SE-G5.1 Pro-B of 5.12 kWh at 51.2V, plus Pylontech, Pytes and Felicity modules in low and high voltage from 2.4 to 16 kWh.
The rack format exists for a practical reason: it lets you start with one module and add identical units in the same cabinet when capacity runs short, keeping a single master BMS and a single link to the inverter. It is the standard for residential storage and equipment rooms.
Check the maximum number of modules in parallel or series the maker declares, cabinet space and floor loading.