LED replacement bulbs
The forward voltage of individual LED varies by color, and other manufacturing details. Here is an example table, showing white light at 3.5V.
Parallel circuits of matched LEDs are possible, years ago series resistors were required, or intensity of each varied.
Most modern automotive LED bulb have built in switch mode regulators that are very efficient. Some bulbs will operate from 10 to 30V DC, and current input reduces as voltage increases, and connection polarity does not matter. Watts consumed is nearly the same, but may decrease with increased temperature. Specifications are not always available at purchase, but with a variable voltage/current bench top power supply, it is possible to carefully test LED bulbs.
The forward voltage of individual LED varies by color, and other manufacturing details. Here is an example table, showing white light at 3.5V.
Parallel circuits of matched LEDs are possible, years ago series resistors were required, or intensity of each varied.
Most modern automotive LED bulb have built in switch mode regulators that are very efficient. Some bulbs will operate from 10 to 30V DC, and current input reduces as voltage increases, and connection polarity does not matter. Watts consumed is nearly the same, but may decrease with increased temperature. Specifications are not always available at purchase, but with a variable voltage/current bench top power supply, it is possible to carefully test LED bulbs.