In storage catalogues, 48V and 51.2V often appear side by side. In practice, many 51.2V batteries are 16-cell LiFePO4 packs, while 48V is still used as a familiar system label.
The important point is not the name printed on the quote. The inverter voltage range, BMS communication and charger settings decide whether the battery is suitable.
Why 51.2V is common for LiFePO4
A LiFePO4 cell has a nominal voltage around 3.2V. Sixteen cells in series create a 51.2V nominal pack. Many modern wall and rack batteries use this format because it is predictable and widely supported by low-voltage hybrid inverters.
When 48V wording still appears
Some suppliers and buyers use 48V as a system shorthand even when the pack is built around LiFePO4 chemistry. This is why the datasheet voltage range matters more than the headline.