Convert a Waveshare Raspberry Pi UPS HAT Into Standalone a 5V Power Supply
by pdp12 in Circuits > Raspberry Pi
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Convert a Waveshare Raspberry Pi UPS HAT Into Standalone a 5V Power Supply
If you happen to have a Waveshare Raspberry Pi UPS HAT handy why not use it as a standalone 5V power bank that can supply about 2.5 Amps? These UPS HATs are great for certain projects but what happens when, for whatever reason, you no longer need it for that project?
In this Instructable I'll show you how to set it up to be a rechargable 5V power bank by adding to it two 3D printed parts, two Dupont wires, a three-digit DC volt meter and four screws/nuts. The HAT itself uses two 18650 batteries so it's a very capable power supply
Supplies
Parts needed:
2 3D printed halves of the enclosure
1 Waveshare Raspberry Pi UPS HAT & Charger - Amazon
2 18650 batteries
1 2.5V-30V Mini Digital DC Voltmeter with 0.28 inch LED Display - Amazon
2 Dupont wires with female ends, 1 red, 1 black, any length is ok since you'll be cutting them anyway
4 M3 X 40mm screws
4 M3 nuts
Gather the Parts
The first step is just to bring all the parts together. Note that the HAT uses the more typical M3 size mounting holes even though Raspberry Pi's are still using M2.5 holes.
Assembly
The assembly is pretty simple so I don't want to over complicate things. Just trim the Dupont wires to about 30mm and the wires on the volt meter to about the same length, making sure that together they will run from the front of the case to the back line of pins on the HAT. Solder them together and cover the solder joints with shrink wrap tubes or electrical tape.
Then plug the red wire onto the leftmost pin (5v) on the back row of pins of the HAT (with the ports facing you) and the black wire onto the 3rd leftmost pin of the same back row (ground).
At this point you can put in the batteries and turn on the HAT. The voltmeter should read 5v or more. In my case 2 fully charged batteries showed 5.21 volts.
Once you know it's working slide the HAT down in the front so the ports fit into the holes in the case bottom and then push the back down so it's flat. Then put the display into the hole. If it's a little loose you can secure it in any of a number of ways. I just put a bit of double-sided tape around the edge and that's enough to hold it in place. You could also add some epoxy or hot glue on the inside to secure it.
Finally add the top and screw then together. If the screws are a tight fit you may have to ream the holes a bit with a 3mm drill bit.
Whenever the voltage drops below 5v just plug in the charger that came with the HAT.