I have WS2812B LED strips, that has 144 LEDs per meter. The ratings are:

  • 43W/M .3W/LED
  • .06A per LED
  • Input Voltage of 5V DC

The recommended power supply stated by the website is 5V DC and 10A for 1 meter. If I wanted to use 400 LEDs that would be 2 7/9 meters. If I based my power supply on the recommendation, that would be around 5V DC and 30A, right?

The question is:

  • Is it possible to use a 12V battery, use a buck-down converter to 5V DC and 40A, and power the LED strip through the buck without doing any damage to the strips?


  • \$\begingroup\$ Are you sure of those specs? 40A would require AWG10 wires, and that’s awfully thick for an LED strip. \$\endgroup\$ Nov 21, 2018 at 7:21
  • \$\begingroup\$ Yeah that's what the store page stated. Perhaps I misread it, here's the link: [link] (amazon.com/gp/product/B01CDTEGGO/…) \$\endgroup\$
    – Bob Wright
    Nov 21, 2018 at 7:33
  • \$\begingroup\$ you read it correctly. But it does indicate to connect supply leads every meter due to wire losses. \$\endgroup\$ Nov 21, 2018 at 7:41

1 Answer 1


In theory there is no problem with your plan, the strip won't be damaged as long as you apply 5V to it. But if we assume 30A load at 5V and 90% efficiency (which is not certain) than you will draw 150W from the buck and about 166W from the battery.At 12V this means about 14A from the battery. An average sized car battery with full charge would be empty in 5-6 hours. And as mentioned in the comments you have to use big wires, otherwise it gets worse. For me a better idea is to buy some 12V LED strip, it would be cheaper and easier than making or buying a 40A buck.

  • \$\begingroup\$ Most addressable led strips are not 12V \$\endgroup\$
    – Passerby
    Nov 21, 2018 at 18:22
  • \$\begingroup\$ The LED strips that I want are sadly 5V. I picked it due to the density if the LEDs per meter. \$\endgroup\$
    – Bob Wright
    Nov 22, 2018 at 2:04

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