Per-cell reference voltages
| Chemistry | Nominal | Charge (CV) | Float | Cutoff (empty) |
|---|---|---|---|---|
| Lead-acid | 2.0 V | 2.45 V | 2.27 V | 1.75 V |
| NiCd / NiMH | 1.2 V | 1.45 V | — | 0.9 V |
| Li-ion (cobalt) | 3.7 V | 4.2 V | — | 2.8 V |
| Li-ion (NMC/NCA) | 3.7 V | 4.2 V | — | 2.8 V |
| LiFePO₄ | 3.2 V | 3.65 V | 3.40 V | 2.5 V |
| LTO (titanate) | 2.4 V | 2.8 V | — | 1.5 V |
Common pack voltages
| Pack | Nominal | Charge | Float |
|---|---|---|---|
| 6 V lead-acid (3s) | 6 V | 7.35 V | 6.80 V |
| 12 V lead-acid (6s) | 12 V | 14.7 V | 13.6 V |
| 24 V lead-acid (12s) | 24 V | 29.4 V | 27.2 V |
| 48 V lead-acid (24s) | 48 V | 58.8 V | 54.4 V |
| 12 V LiFePO₄ (4s) | 12.8 V | 14.6 V | 13.6 V |
| 24 V LiFePO₄ (8s) | 25.6 V | 29.2 V | 27.2 V |
| 48 V LiFePO₄ (16s) | 51.2 V | 58.4 V | 54.4 V |
| Phone (1s Li-ion) | 3.7 V | 4.2 V | — |
| Laptop (3s Li-ion) | 11.1 V | 12.6 V | — |
| EV (96s Li-ion) | 355 V | 403 V | — |
Notes
- CC/CV: constant current until CV voltage, then hold CV while current tapers — terminate at C/10–C/20.
- Temperature compensation: lead-acid float voltage drops ~3 mV/°C/cell above 25 °C; don't charge Li below 0 °C.
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