Battery Voltage
Q. Nominal battery voltage is typically _____.
b) 1.2V per cell for alkali systems
c) 4V per cell for lithium-ion systems
d) all of the above
See answer and applicable Code reference
The correct answer is: d) all of the above
You can find the definition of "nominal battery voltage" in Sec. 480.2 of the 2011 NEC. The Informational Note in this section notes the most common nominal cell voltages for the three types of battery chemistries noted above.