How do you read a LiFePO4 datasheet: nominal, charge and cut-off voltage?

Direct answer: Nominal voltage is the average working voltage used to name the battery and calculate energy (nominal voltage × Ah). Maximum charge voltage is the ceiling a charger must not exceed. Discharge cut-off is the lowest voltage before the battery protects itself. Together they set the window that your charger, inverter or motor controller must fit. Compare batteries on these values, not on the label name.

Worked examples. The 12V 100Ah page lists 12.8V nominal, 14.6V maximum charge and 10V cut-off. The 48V 100Ah golf cart battery lists 51.2V, 58.4V and 40V. The 36V 100Ah lists 38.4V, 43.8V and 30V. Our arithmetic: LiFePO4 cells are commonly rated at 3.2V nominal, so these correspond to 4, 16 and 12 cells in series, with 3.65V per cell at full charge and 2.5V per cell at cut-off.

Why “48V” can mean two things. The same site also lists a 48V 150Ah golf cart pack at 48V nominal, 54.75V maximum charge and 37.5V cut-off, and the PM-LV48100-3U rack battery at 48V, 54.75V and 37.5V. Those figures fit 15 cells rather than 16 (our arithmetic). A 15-cell and a 16-cell pack need different charger settings, so read the table, not the name. Our post on 48V vs 51.2V rack batteries applies the same check to inverters.

Energy. Nominal energy = nominal voltage × capacity: 51.2V × 100Ah = 5,120Wh, which matches the 5.12 kWh on the 48V page. Use this, not Ah alone, when comparing packs of different voltage.

Currents. “Standard charge current” is the routine rate (22A on the 48V and 36V 100Ah golf pages, with about 5 hours to full stated). “Maximum continuous charge current” is the upper limit (100A on both). Discharge currents are read the same way, with any peak value tied to the duration shown in brackets.

Temperatures and conditions. Charge temperature (0–60 °C on these pages) is narrower than discharge temperature (−20–65 °C). Cycle-life numbers carry conditions in brackets, such as 80% DOD; compare only like with like.

What to do with it: set the charger’s maximum at or below the charge voltage, set any device low-voltage cut-off above the battery cut-off, and confirm that your controller’s operating window covers the whole range.