Is it possible to operate a 12V LED strip at a voltage lower than 12V?

When searching for LED strip lights, you will certainly encounter specifications like DC 12V or DC 24V. This is the necessary input voltage to activate the LED strip light.
What is the definition of "required"? It is intuitively evident that supplying more than 12V DC to a 12V LED strip is inadvisable, since it may result in overdriving the LED strip, leading to diode burnout or excessive heat accumulation that can harm both the circuit and onboard components. What occurs if we provide 11V or even 9V? Is that permissible? Is it detrimental to the LED?
The concise response is negative; utilizing a voltage level below the specified range is entirely permissible and secure. We conducted experiments to furnish you with empirical facts, enabling you to anticipate the outcomes of under-driving your LED strip lights.

What is the significance of this?

Prior to discussing our test configuration and outcomes, you may be curious about the circumstances under which an LED strip may be under-driven, or whether under-driving an LED is relevant to your specific setup.
LED strips are engineered at the circuit level to operate at a designated voltage. We provide 12V and 24V DC power supply compatible with our 12V and 24V DC LED strips, ensuring that the voltage typically aligns precisely.
Nearly all parameters, including power consumption per foot and lumens per foot, presume that the supplied voltage is precisely at the rated level (i.e., 12V DC or 24V DC).
Consequently, it is entirely safe and acceptable to under-drive an LED strip by providing a voltage lower than its rated specification. However, the majority of LED strip products fail to disclose information regarding the impact of under-voltage on performance, prompting us to undertake our own testing. Our test results indicate some approximate estimations that may be utilized.
Three principal scenarios may result in a power supply voltage that is inferior to the LED strip voltage standard. The initial decision involves deliberately utilizing a reduced voltage to attain a diminished light output compared to the specified rating. You may discover that 450 lumens at 5.5 watts per foot exceeds your requirements, prompting a preference for operating the LED strips at 2.3 watts per foot instead. Employing a 20V power source for a 24V LED strip may serve as a straightforward and efficient method to accomplish this without the necessity of acquiring and installing a dimmer.
The second scenario may emerge from prevailing system limitations. When installing LED strips on a battery system, the power supply voltage may decrease below 12V DC as the system drains. The data provided below will assist in assessing the expected power usage when the supply voltage falls below the LED strip's rated voltage.
The third scenario may arise from inadequate wire gauge and the consequent voltage drop. Excessive current flowing through an inadequately thick long copper wire can result in a voltage drop prior to energizing the LED strip.
 

Our Experimental Configuration

We connected a 1-foot (30 cm) piece of our Ultra High 95 CRI LED strip lights to a tabletop power supply. The benchtop power supply features adjustable input voltage, and we recorded the current draw as a function of input voltage in 0.1V increments.
We conducted this test for both the 12V and 24V variants.
Initially, we tested the current draw at the specified rated voltage, then reducing the voltage in increments of 0.1V and recording the current draw readings. The results are illustrated on a chart below.
It is essential to acknowledge that these results are derived from a restricted number of tests conducted just on our LED strip lights. Outcomes will vary between distinct goods and manufacturers.

Overall Insights from Our Test Outcomes

The initial observation is that the LED strips illuminate only upon reaching a minimum threshold voltage. The voltage is around 7.5V for 12V LED strips and 15.5V for 24V LED strips. This is quite counterintuitive, since it suggests that one cannot only anticipate a 6V power supply input on a 12V LED strip to yield half the power. Investigate the principles of diode voltages and circuits, and the rationale behind them.

Beyond this minimum threshold voltage, power consumption escalates by about 1.0 watts per foot for every 0.75-volt rise in 12V LED strips and by 1.5 watts per foot for every 1.5-volt increase in 24V LED strips.
A typical voltage level for laptop power supplies is 19.5V DC, which may prove beneficial if you are in a predicament and possess no alternative power supply. Our findings indicate that a 19.5V DC input yields a power level of around 2.0 watts per foot on a 24V DC LED strip, effectively reducing light output by nearly 60% with simplicity and efficiency.

Disadvantages of Under Voltage Operation

As previously stated, using LED strips at a voltage lower than their authorized capacity is entirely safe and does not adversely affect the LEDs or the circuitry.
Operating the LED strips below their rated current will theoretically extend their lifespan and durability.
From a technical perspective, there are no discernible drawbacks. From a pragmatic standpoint? The sole disadvantage is that you are, in effect, overcompensating for power capacity.
A high-quality LED strip is engineered to deliver a specific brightness level, incorporating an adequate number of LEDs per foot and sufficient copper thickness to manage the power requirements. This necessarily implies that you are incurring greater costs for superior quality and quantity of components and resources; nevertheless, by underutilizing them, you are not maximizing their potential. It is akin to purchasing a sports automobile then limiting its speed to 50 kilometers per hour.