The voltage value of the lithium battery is shown with the corresponding lithium battery. A 48V lithium battery typically consists of 13 cells connected in series. When changing to 12V, simply convert the number of cells to the nearest 12V serial value. The problem is that the lithium battery has a management module or protection board. Protection boards with different voltages are not universal. The 48V protection board cannot be used in 12V. The number of battery cells in series can be changed and the protection. The board should be replaced depending on the voltage value. There is nothing else special about it.
There are now backing cards that are backward compatible with serial numbers, and they can be used, but compatible backing cards are overkill.