DZS Elec Mini DC 6-24V 24V 12V to 5V 3A USB Buck Voltage Converter Regulator Power Supply Module USB Charging Step Down Voltage Module

This is a nice little USB charger. I bought it to go along with a 12V battery bank that did not have a charging port. I mounted it in a small plastic container for ear plugs with an input plug from the battery bank. The efficiency of this charger meant that the 12V, 3000mah capacity of the battery bank will deliver a measured 5V, 5700 mah at the output of this charger - two full charges for my phone. I use the 12V battery bank for other purposes as well, but this is a nice added capability. If you haven't bought the battery bank yet, you can find some that already have this USB charger built in. However, if you also use the battery bank for low-noise applications, you might want to have a removable charger like this to eliminate the switching noise from the battery output when you are not using it. Nice product, worth a few dollars more.ADDITION: I noticed that the cable between this charger and my phone affected the charging current. My Samsung Galaxy 4 would only charge with 420 ma with a long cord, but would charge at 1.5 amp + with a short stub cable. This is because the phone detects the voltage drop in the cable and limits charging current. If you want to use the fast charge capability of this charger, make sure you use your shortest, heaviest cable between the charger and phone.

I purchased this to use inside a case with a ham radio, and needed 5 volts to power a raspberry pi. It works great, easy to use, plenty of power for the Pi3. Only problem is: There are NO mounting holes. I wound up screwing a plastic piece to the chassis and gluing this thing down to the plastic with E6000. If there were a couple of standoff holes this would be SO much better.

I haven't had a chance to apply this board to my project yet, but I noticed some interesting things about it right out of the box that I thought were worth sharing. Though it can be seen in the pictures if you look carefully, the description does not mention the power indicator LED. I thought this was a neat feature. Another thing that isn't stated in the description is that the board draws ~5 mA without anything plugged into the USB port. Beyond those observations, I just tested that it output 5v, which it did.

for some reason this thing drains my battery even when nothing is connected to USB.... Wasn't expecting that.... I have to pop out 9V I have wire to it when I'm not using, or else its completely dead the next day. Tested this with 2 fresh 9V and nothing plugged into USB port.

I bought this to build my own solar panels for charging my power banks remotely.It was easy to solder to the solar panels I set up and works great.

I added input / output capacitors (150uF) and the stability of mine got much better. I think my phone would test the current capacity, detect too much droop, and back off charging current. After the caps, full current all the time!

Used on my 3d printer to power my PI for octoprint. It's does run kinda warm though...

Worked as expected, very nice. I used it for a Raspberry Pi project