Powering LED strip with U3V70F5 regulator

Hello all. I have an LED strip that pulls no more then 3A @ 5v, I was hoping to power them with the most voltage to get them the most brightness, as for the type of led they are WS2812B and each has its own tiny capacitor.

For powering:
18650 lion 3000mah 2.5v-4.2v range that states it has Max, 15A discharge current, it also has over discharge protection.

I’m using 5v step-up U3V70F5 Voltage regulator

But it seems when my load is connected it drops down the output voltage from U3V70F5 drops to around 3.8v

with no load connected the battery was resting at 4v
3.2v input voltage from battery to U3V70F5 and 3.8v being measured on the output. 3A of current being drawn from the 18650 side and one can expect to see the voltage drop when under load, and only 2.5A being drawn from LED side set full brightness steady on white where can expect the most load.

Can anyone explain what is happening to my output? I was aiming for steady 5v supply for max brightness to my led strip.


I moved your post to it’s own thread to keep the discussion organized.

Can you post some pictures that show your connections?

Since your input voltage is also dropping when you add the regulator, I suspect that your battery cannot handle the increased load from trying to power the LEDs at the higher voltage. You might try testing your setup with only some of the LEDs turned on, and then you could try increasing the number of LEDs turned on while monitoring the supply and regulator voltages to see where the voltage starts dropping.

- Patrick