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