I am currently working on an Arduino project and I want the Arduino to control a 5-meter long LED strip, which (as the producer said) needs 18 A and 5 V.

My chosen cable is this one.

I heard a lot of confusing things like powering it from two sides.

What do I do in that case? Do I just put an 18 A at the end, or do I just ram another power cable in the power line? When I need to power from two ends, do I supply both with 9 or 18 A?

I know that's a lot of questions, I'm new to powering.

  • 1
    \$\begingroup\$ Same power supply, just wire it to both ends. If you wire it to one end, you will probably see that when the strip is bright enough, the LEDs at the other end don't get enough voltage to make the blue part work; the end where it's wired may also get hot \$\endgroup\$
    – user253751
    Feb 21, 2023 at 19:31
  • 1
    \$\begingroup\$ Related answer: electronics.stackexchange.com/a/423656/2028 \$\endgroup\$
    – JYelton
    Feb 21, 2023 at 19:31
  • 1
    \$\begingroup\$ I had problems with 9 amps on a similar 5m LED strip (half as many LEDs I guess). Maybe their one uses twice as thick power traces, but I dunno - it's Ali Express and all of these strips are built for price. If you wire it to power at both ends and the middle still isn't blue enough, then wire the power to the middle as well. \$\endgroup\$
    – user253751
    Feb 21, 2023 at 19:33
  • \$\begingroup\$ if you like, you can visualize the extra wiring as just reinforcing the wiring that is already built into the LED strip but is too small. \$\endgroup\$
    – user253751
    Feb 21, 2023 at 19:45
  • \$\begingroup\$ If it’s going to have current regulated brightness, all you need is ensure to meet spec at connection under loads, whether that’s a 0.5” copper pipe or AWG 10 depending on length and feed loop resistance. \$\endgroup\$
    – Hoagie
    Feb 21, 2023 at 21:20

1 Answer 1


There are many guides to doing this on Google which you may want to check, but essentially you run a power and a ground line from your power supply to power and ground on both ends of the strip. Depending on how much current and the strip itself you may also need to hook a third pair of wires to the strip in the middle as well.

when i need to power from two ends, do i suplly both with 9 or 18 amp?

You supply voltage, not current, so you would use 5v. The power supply has to be able to be able to supply at least 18A if that is what the strip requires.

  • 1
    \$\begingroup\$ Also if you are doing 18 A, I would be looking at 14 or 12 gauge wire. \$\endgroup\$
    – vir
    Feb 21, 2023 at 19:41
  • \$\begingroup\$ I would use #10 until you split to go to the ends and middle. 24V would only use 1/2 the current. \$\endgroup\$
    – Gil
    Feb 21, 2023 at 20:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.