13V

13V denotes an electrical potential difference of 13 volts. This value can refer to a direct-current (DC) supply in electronic equipment or to a nominal reading in a given electrical system. Voltage is measured with respect to a reference point, typically ground, and a device rated for 13V expects a supply around that magnitude within tolerance.

In automotive systems, 12V is the standard nominal battery voltage. When the engine is running, the charging voltage delivered by the alternator is typically about 13.8 to 14.4 V to maintain the battery. Consequently, a measure of approximately 13 V can occur under certain conditions such as moderate load or battery aging.

In electronics, many devices use 12V DC supplies, but some equipment and lab power supplies can be configured to 13V or include adjustable regulation. Devices rated for 13V require a regulated 13V supply or an adapter that maintains voltage within a specified tolerance, often around ±5% or better.

Safety and standards: 13V is well below lethal shock thresholds for adults, but circuit components have voltage tolerances and current ratings. Proper regulation and protection, such as fusing and over-voltage protection, are still important for any DC power system.

See also 12V, 24V systems; voltage regulator; DC power supply.