Voltage in Permanent Outdoor Lighting: 5V, 12V, 24V, and 48V Explained

The Three Things to Know About Voltage

Voltage is listed on almost every permanent lighting spec sheet, but the number alone tells you little. These three points explain what it changes.

Higher Voltage = Less Heat

Heat in a wire is determined by current, not voltage. P = V × I. Doubling the voltage halves the current. Halving the current cuts wire heat by 75 percent.

Brightness Comes From Current

As Bowdrie puts it in the video, "voltage doesn't necessarily mean brightness, but current does." Higher-voltage systems carry current better, so a 48V run keeps steady power all the way down the roofline. On a lower-voltage run, voltage drop can make the lights at the far end dim unless the installer adds more power injection points.

Engineering Beats Voltage Alone

A poorly designed 48-volt system can still lose to a well-built 12-volt one. The chip, the driver, the protection circuitry and the app decide whether a high-voltage spec becomes a reliable install.

What Is Voltage and Why Does It Matter in Permanent Lighting?

Voltage in a permanent outdoor lighting system controls how far the system can carry power before it needs more help. It affects how much heat builds up in the wire, how consistent the brightness stays across a long run, and how many physical boxes end up mounted on your fascia. Brightness comes from current, and a higher-voltage system holds current steadier over a long run, so the lights at the far end do not dim the way they can on a low-voltage run.

The four voltage tiers you see in this category are 5V, 12V, 24V, and 48V. Each was originally designed for a different use case. 5V chips were designed for indoor electronics and short LED strip runs. 12V is the legacy permanent-lighting voltage. 24V is the current mid-range. Newer high-end systems use 48V, and so does TruLight.

How Many Power Injection Boxes Does Each Voltage Need?

This is where voltage tiers differ most on a real house. Every power injection adds a box on your fascia and wires through your soffit, plus one more connection that can fail. Lower-voltage systems need many more of them.

5-Volt Systems

Power injection every 5 to 10 lights on indoor strip lighting, which is what 5V is built for. It is not meant for residential rooflines. A 5V roofline product goes a little farther, needing an injection roughly every 10 to 30 lights, but that is still far more often than a 48V system.

12-Volt Systems

Power injection every 50 to 70 lights. Trimlight, Bosso and Gemstone all use 12V.

24-Volt Systems

Power injection every 50 to 100 lights. This is the mid-range, where Celebright and Haven's EVO sit.

48-Volt Systems (TruLight)

Power injection every 400 or more lights. Bowdrie estimates that 90 percent of the homes TruLight installs need one injection box or less, because most homes have under 300 linear feet of roofline.

In the video, Bowdrie describes a dealer who pulled out a 12-volt competitor's install with 15 power injection boxes on the front of one home, each with its own wires through the fascia. On a 48-volt system, which goes about 400 lights between injections, the front of a typical home needs none.

Why Higher Voltage Means Less Heat in the Wire

P = V × I. Power equals voltage times current. To deliver the same amount of power, a higher-voltage system needs less current. Heat in a wire is determined by current squared times resistance (Q = I² × R), not by voltage. Halving the current cuts wire heat by 75 percent. Less heat at the connectors means less expansion and contraction over time, which is easier on the components and helps them last longer.

Vicor, a major power-electronics manufacturer, publishes the math directly in their technical literature: “By increasing the bus voltage to 48V you can cut your distribution losses up to 75%, which dramatically reduces heat generation.”

The power grid works the same way. Utilities send electricity at hundreds of thousands of volts and step it down at a substation near your house, because higher voltage loses less to heat over distance. A permanent lighting run follows the same principle on a much smaller scale.

Not All 48-Volt Systems Are Equal

Voltage alone does not make a system good. Bowdrie says a poorly designed 48-volt system can still be worse than a great 12-volt system. Higher voltage needs better voltage conversion and protection circuitry, and a chip designed for it. He says he would pick a proven 12-volt system over a generic 48-volt light someone found online and paired with a cheap app.

TruLight pairs its 48-volt bus with the UCS7604 chip, 6 LEDs per node (3 RGB plus 3 dedicated warm white) and an app built for this hardware. The UCS7604 was designed for higher-voltage RGBW lights.

Voltage Tier Comparison

Why Lumens Marketing Can Mislead You

Lumens are a real unit of measurement, but how a company reports them is wide open. A cheap lumen meter and a premium lumen meter give very different readings. Distance to the source, angle, ambient light, and even the meter brand all affect the number. In the video, Bowdrie holds a single light at different distances from a lumen meter, and the reading swings from 100 to about 800.

Brightness comes from current, and a higher-voltage system holds current steadier along a long run. A lumen reading taken at one light says little about how even the whole roofline will look.

If a permanent lighting company leads its pitch with a high lumen number, ask at what distance, with what meter, and at what point on the run it was measured.

A Note on Misleading Marketing Claims

A 24-volt brand published an article titled “Permanent Outdoor Lights: The Hidden Cost Of 48-Volt Lighting Systems” arguing that 48V systems “put a lot of power running through the wires, which creates a lot of heat” and that this leads to a shorter lifespan. That framing inverts P = V × I. Higher voltage means lower current at the same power, and lower current means less heat. We address that article directly in the video.

Voltage is easy to misstate in marketing copy, so read any claim about it with P = V × I in mind. Ask the installer why their voltage suits your home and what it changes about the install. A good answer is specific and backed by public data.

Straight From the Video