Lead Acid Battery Voltage Chart: Complete 12V, 24V, 48V Reference Guide

Understanding battery voltage is fundamental to designing and maintaining any energy storage system. This complete reference guide covers charging, float, and discharge voltages for all common system configurations.

12V Battery System Voltages

• Bulk/Absorb charge: 14.4–14.8V (AGM: 14.4–14.7V, Gel: 14.1–14.4V, OPzV: 14.1–14.4V)
• Float charge: 13.5–13.8V (AGM: 13.6–13.8V, Gel: 13.5–13.8V, OPzV: 13.5–13.8V)
• Discharge cutoff: 10.5V per battery (never go below this)
• Resting voltage (full): 12.7–12.8V after 1 hour rest
• Resting voltage (50% DoD): 12.2V
• Resting voltage (80% DoD): 11.8V

24V Battery System Voltages

• Bulk/Absorb: 28.8–29.6V (2 x 12V batteries in series)
• Float: 27.0–27.6V
• Discharge cutoff: 21.0V (2 x 10.5V)
• Resting voltage (full): 25.4–25.6V

48V Battery System Voltages

• Bulk/Absorb: 57.6–59.2V (4 x 12V batteries or 24 x 2V cells)
• Float: 54.0–55.2V
• Discharge cutoff: 42.0V (4 x 10.5V)
• Resting voltage (full): 50.8–51.2V

2V Cell Voltages (per cell)

• Bulk charge: 2.40–2.45V/cell
• Float: 2.25–2.30V/cell
• Discharge cutoff: 1.75V/cell (never go below 1.75V)
• Resting full: 2.10–2.15V/cell

Critical rule: Always use voltage settings for your specific battery type. Wrong voltage damages batteries and void warranties.

Temperature Compensation

All voltages above are at 25C (77F). Add +4mV per cell per degree C below 25C. Subtract -4mV per cell per degree C above 25C.