RV Battery Voltage Chart
Free battery state of charge chart - check 12V battery percentage by voltage. Lookup tables for lead-acid, AGM, gel and lithium LiFePO4 RV batteries.
BATTERY VOLTAGE
Check Your Battery
V
Measure at rest (no load, no charging) for accurate reading.
Voltage to State of Charge
| State of Charge | Lead-Acid | AGM | Gel | LiFePO4 |
|---|---|---|---|---|
| 100% | 12.70V | 12.80V | 12.85V | 13.60V |
| 90% | 12.50V | 12.60V | 12.65V | 13.40V |
| 80% | 12.42V | 12.50V | 12.55V | 13.30V |
| 70% | 12.32V | 12.40V | 12.45V | 13.20V |
| 60% | 12.20V | 12.25V | 12.30V | 13.10V |
| 50% | 12.06V | 12.10V | 12.15V | 13.00V |
| 40% | 11.90V | 11.95V | 12.00V | 12.90V |
| 30% | 11.75V | 11.80V | 11.85V | 12.80V |
| 20% | 11.58V | 11.65V | 11.70V | 12.60V |
| 10% | 11.31V | 11.40V | 11.45V | 12.00V |
| 0% | 10.50V | 10.50V | 10.50V | 10.00V |
Battery Voltage Tips
Resting Voltage
For accurate readings, let the battery rest for 2-4 hours after charging or discharging. Under load or while charging, voltage will read differently.
Temperature Effects
Cold batteries read lower voltage. Readings above are for ~77°F (25°C). Adjust expectations in extreme temps.
Don't Over-Discharge
- Lead-Acid/AGM: Stop at 50% (12.0V) to preserve battery life
- Lithium: Can go to 20% regularly, but BMS will cut off before damage
Lithium is Flat
LiFePO4 batteries hold ~13.2V for most of their discharge cycle, then drop quickly. Voltage is less useful for state of charge - use a battery monitor instead.
For educational purposes only — full disclaimer ↓