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Lead Acid

12V Battery

Voltage table for cyclic use charging

The higher voltages (above the gassing voltage) should only be used on flooded batteries that can have the water replaced:
Battery Temperature Charge Voltage per cell Charge Voltage for a 12 Volt battery Gassing Voltage per cell Gassing Voltage for a 12V battery
-20 °C * 2.67 to 2.76 16.02 to 16.56 2.97 17.82
-10 °C * 2.61 to 2.70 15.66 to 16.2 2.65 15.9
0 ° C * 2.55 to 2.65 15.3 to 15.9 2.54 15.24
10 °C 2.49 to 2.59 14.94 to 15.54 2.47 14.82
20 °C 2.43 to 2.53 14.58 to 15.18 2.415 14.49
25 °C 2.40 to 2.50 14.40 to 15.00 2.39 14.34
30 °C 2.37 to 2.47 14.22 to 14.82 2.365 14.19
40 °C 2.31 to 2.41 13.86 to 14.46 2.33 13.98
50 °C 2.25 to 2.35 13.5 to 14.10 2.30 13.8

Voltage table for standby use charging

Battery Temperature Charge Voltage per cell Charge Voltage for 12V Battery Gassing voltage
-30 °C * 2.44 14.6  
-20 °C * 2.34 to 2.38 14.04 to 14.28 2.97
-10 °C * 2.32 to 2.37 13.92 to 14.22 2.65
0 °C 2.30 to 2.35 13.8 to 14.1 2.54
10 °C 2.28 to 2.33 13.68 to 13.98 2.47
20 °C 2.26 to 2.31 13.56 to 13.86 2.415
25 °C 2.25 to 2.30 13.5 to 13.8 2.39
30 °C 2.24 to 2.29 13.44 to 13.74 2.365
40 °C 2.22 to 2.27 13.32 to 13.62 2.33
50 °C 2.20 to 2.25 13.2 to 13.5 2.30
  • Note that a fully discharged battery freezes solid at about 0°C, a fully charged battery freezes about -72°C. This is why a discharged battery won't take a charge in sub-freezing weather.

References

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