LED 5050 light strip battery life

am working on a project that requires 2m 5050 4.5 led light strip. i require the lights to be on continuously for 72 hrs+. i connected these up to a 50000 mah power bank via a Usb thinking this would last well over the 72hrs it only lasted 4hrs. Yesterday i connected them to 4 X AA batteries (just the cheap standard ones) and they have lasted over 24hrs though have gotten a lot dimmer. i really don’t understand could anyone explain what is happening it doesn’t make sense to me?. How can 4 AA batteries out last a 50000 Mah power bank ?.

Hi @Damien58335.

How many LEDs per meter is the strip?

its 60 LEDs per metre

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Great, thanks Damien. In our testing, we found that the 60 per meter use ~2.1 A/ meter @5V (Full-brightness white). A very unlikely scenario though, running all LEDs at full brightness constantly.

If your LED strip is anything like ours, this means a 2100mAh 5V battery could power the LEDs for 1 hour (in a perfect world). 50000mAh 5V would last 50000/2100 = 23.8 hours of full white brightness. If you instead have patterns/effects then a few days would be easily achieved in most situations, weeks for some cases.

If you are getting less then that, these thoughts come to mind:

  • The 50000mAh battery pack is not taking full charge for some reason
  • WS2812 LEDs need around 4.5-5V to operate, it’s possible that your 50000mAh power bank is dropping below 4.5V which creates a reset condition for the WS2812 chips (would “appear” to be off or intermittant)
  • Significant energy is being used by something else in the circuit, other than the LEDs.

The second point is perhaps more likely, if you are using anything other than a LiPo battery bank.