5pcs DC-DC Buck Step Down Module 6-20V 12V/20V to 5V 3A USB Charger Module

Power terminals not marked + or - and are polarity dependentDrops below 5v after 900ma and is at ~4.5v at 3000maShould work fine for the raspberry pi setup I have but it shouldn't be advertised to hold a 3amp load or even 1amp for that matter

I bought 15 of these, and run them directly from Creality Ender 3 printer power supplies (which are 24V), so that I can integrate my Pi's into the printers, and also free up precious wall plugs that I was needlessly running out of by using pi power supplies.The first batch of these arrived all bent up inside their bag, and I had no issue with them replacing them. Out of the 15, I had one that would not power on, and one that would give me the lightning bolt icon in octoprint, signifying that the pi was not getting enough current. All the other ones worked flawlessly and had no issues with underpowering even the pi 4's. For the price, and the ability to supply enough power in this small form factor, I can overlook 2 out of 15 of them being bad.Also, I saw earlier comments stating that they did not have positive and negative marked out, but they must have rectified that because mine were labeled.

I always have old power supplies hanging around, but they are all of different voltages. I have old laptop supplies, router power supplies. With this device you can convert almost any 6 to 24V supply into a 5V supply for Arduino USB and Raspberry PI boards.

I have a pack of 5 and am only using 1. I’m using this to power a raspberry pi 4 with pi camera on a 3D printer 24v power supply. I was getting under volt errors on a usb wall charger with octopi but I’m not getting them with this.Voltage is less than 5 volts with the pi 4 connected through a usb power meter. The pi isn’t taking the full 3 amps. At the 3 amp draw, I expect the voltage would be even lower.Polarity of inputs isn’t marked but not too hard to figure out. Negative input has continuity to output ground.

I am getting the voltage message whenever I use these converters for octopi, not attaching anything crazy to the pi, just one camera. Definitely do not recommend getting these for that purpose. If it works for you then you were lucky.No marks on the board on which one is positive and negative, so unless you really know your electronics... you will have a hard time soldering correctly.Don't be cheap, just get something better for your pi, you will just end up getting it anyways.