To choose the right protection board, the first thing is to figure out the material type of the cell, the basic material classification can be divided into:
Li-ion(3.7V), LifePo4(3.2V), LTO(2.4V), according to the voltage to the following, select the appropriate number of strings.
| Voltage | Li-ion | LifePo4 | LTO |
| 12V | 3S | 4S | 5S |
| 24V | 7S | 8S | 10S |
| 36V | 10S | 12S | 15S |
| 48V | 13S | 15S | 22S |
| 60V | 16S | 19S | 27S |
| 72V | 20S | 23S | 32S |
| 84V | 24S | 28S | 35S |