How long can a long LED strip run be on a single power feed?
A standard 24V constant-voltage tape is limited to roughly 5 m before the far end visibly dims. Long run LED strip lights solve that with three changes at once: heavier copper (2 oz to 3 oz instead of 1 oz), a higher input voltage (24V, 36V or 48V) and a linear constant-current IC on every segment. With all three, DENO boards hold measured output across a 20 m single feed, and up to 50 m on 48V builds, with no perceptible difference between the first and last metre.
Why voltage drop, not the LED, sets the limit
Copper has resistance. Current drawn by every LED downstream flows through the same trace, so the voltage available at the far end is always lower than at the feed. Constant-voltage tape reacts to that by dropping drive current, which shows up as dimming and, on warm white, a slight colour shift. Doubling the input voltage halves the current for the same wattage, and the loss falls with the square of that current — which is why a 48V board reaches far beyond a 12V one.
Copper weight is the second lever. Going from 1 oz to 2 oz halves trace resistance; 3 oz cuts it again. DENO plates copper roll-to-roll rather than laminating and etching panels, so the heavy-copper long boards stay flexible and are produced as one continuous length instead of joined sections.
What a constant-current IC changes on a long board
A per-segment constant-current IC regulates the current its own segment receives, so each segment produces the same flux regardless of the local voltage it sees. That converts the run-length question from 'how much dimming can you accept' into 'how much current can the copper carry safely'.
- 24V + 2 oz copper + CC IC — up to 20 m per feed
- 36V + 2 oz copper — 30 m class runs, 100 mm cut units
- 48V + 3 oz copper — up to 50 m per feed
- Both-ends or mid-feed wiring halves the electrical distance again
- Always size the driver for the whole run, not for a 5 m reel
Industry references and standards
- Energy & compliance — EU Regulation 2019/2020 (ErP for Light Sources) — Efficacy, flicker (Pst LM) and SVM limits that apply to strips sold in the EU.
- Energy & compliance — ENERGY STAR Lighting Program — North American efficacy and lumen-maintenance benchmarks.
- Engineering standards — IEC 62717 — LED Modules for General Lighting — Performance and lumen-maintenance requirements for LED modules.
More long run answers
- What are the longest LED light strips DENO manufactures?
- Can you get LED strip lights longer than 32 feet in one run?
- Should I specify a 65.6 ft or a 100 ft LED strip run?
- Can a long RGB or RGBIC strip run stay colour-consistent?
- When is a long RGBW LED strip better than RGB on a long run?
- Is 36V or 48V better for a long LED strip installation?
Published by DENO LED Lighting — denoled.com, a custom long run LED strip manufacturer serving EU, Americas and Middle East projects.