Tools:
Fine tip hand tool and solder
Epoxy or super glue
Scissors or wire cutters
Supplies:
3D printed enclosure
PowerBoost 500 charger
2.5w solar array
Panel mount USB port
1N4001 blocking diode
Lithium ion battery and battery holder
Panel mount power button
Hook up wire
Step 1: About the Components
The AllPowers 2.5 watt solar array is among the simplest available on Amazon. It produces about 6.2v circuit and 5.6v under load at up to 500 mah fully sunlight. For this project I used an inline 1N4001 blocking diode to stay the panel from discharging the battery. The 1N4001 can handle up to 1 amp continuous current and drops the voltage about 0.7v, which is ideal for the input on the charging board.
Adafruit PowerBoost 500 Charger:
The PowerBoost 500 may be a dual Li-Poly charger and DC/DC boost board. It charges lithium ion and polymer batteries at a rate of 500mah (perfect for the solar array during this project) and outputs 5.2v at up to 1 amp to charge devices. It allows for simultaneous battery charging and cargo . it’s a simple to read pinout and connections for an external power switch. Because the facility switch doesn’t carry the circuit’s current load, almost any switch or button are often used. For this project I used one 18650 battery, but the board will charge many sorts of single cell batteries. it’s A battery management system (BMS) with over-charge, over-discharge, and over-current protection. There are cheaper battery charging boards (TP4056) and DC/DC boost boards available, but the standard of the Adafruit board ensures that it’ll be safe to use when charging expensive devices!
Step 2: Printing the Enclosure
I sliced the model in Cura 4.3 using the recommended settings for top detail:
0.2mm layer height
20% grid infill
30mm/s printing speed
0.5mm wall thickness
Brim type skirt and automatic support generation
I printed the enclosure on a Lulzbot TAZ 6 in 2.85mm PLA, but most 3D printers should be ready to handle this print (just confirm the print bed is large enough). If you do not have a 3D printer, the .stl file are often uploaded to Treatstock.com (a 3D printing service) and printed/mailed for about $20 USD. The print takes approximately 8 hours and uses 170g of fabric . I used a 205C nozzle and 60C bed temperature.
Step 3: Preparing the USB Port
Red: +5v
Black: Ground
White: Data +
Green: Data –
iPhones and a couple of other devices require a particular voltage across the info pins before the device will recognize an influence source and start charging. Most other devices only require +5v and a ground. If you propose to use this solar charger for Apple products, you will need to wire the info + and data – pins from the USB port to the board.
Step 4: Wiring the Components
The solar array connects to the USB (+) and GND (-) pins with the diode inline on the + wire
The power button connects to the EN and GND pins, which wire goes where doesn’t matter
The battery connects to the Bat (+) and GND (-) pins
The USB port connects to the USB + (+) and USB – (-) pins on the proper side of the board
The D+ (green) and D- (white) wires hook up with the proper side of the board if needed
AN IMPORTANT NOTE: Because the USB port and therefore the power button are installed in through holes within the enclosure, remember to run the wires through the holes before soldering them to the board!
Step 5: Installing the Components
Push the panel mount USB port into the through hole. it’s tabs that lock it into place. Add a touch little bit of glue or epoxy to form sure its secure and to stay the USB port horizontal within the enclosure.
Thread the facility button into the opposite through hole and tighten the nut on the rear . like the USB port, add a touch glue or epoxy to form sure it is not going anywhere.
I also glued the diode to the underside of the solar array and added glue over the soldered wires for extra durability.
Step 6: Testing and Final Assembly
Blue: indicates that the boost converter is active and producing 5v
Red: indicates low battery (3.2v)
Yellow: indicates that the battery is being charged
Green: indicates when the battery is fully charged (4.2v)
First you’ll be wanting to check whether the solar array can charge the battery. to try to to this, aim the solar array at the sun and check to ascertain if the yellow indicator light is on. this suggests that power from the panel is being sent to the PowerBoost, which the PowerBoost is charging the battery.
Second, you’ll be wanting to form sure the PowerBoost can charge your devices (and that the facility switch is functional). to try to to this, press the facility button and you ought to see the blue indicator LED illuminate . Press the button again and it should leave . If the switch doesn’t work, the charger board will continuously draw power from the battery even when no device is being charged. If the indicator is on, connect a tool via the USB port and confirm it’s actively charging.
If everything works the way it should, then the solar charger is prepared for final assembly. Simply apply a bead of epoxy or some super glue to the rim of the enclosure and press the solar array into place, ensuring that it’s flush all the way around and not squishing any wires underneath. That’s it! You now have a totally functional solar charger for all of your devices.
Step 7: Adding a Personal Touch
The PowerBoost board can accommodate many shapes and sizes of batteries, many sorts of power buttons, and lots of inputs. With this in mind, you could:
Change the diameter of the through hole for the USB port to include other output port types like USB C or a barrel jack
Change the diameter of the through hole for the facility button to fit your own power button or toggle
Change the size of the enclosure for a special sized solar array
Make the enclosure super thin by employing a flat lithium polymer battery rather than an 18650 cell
Add an influence indicator by connecting an LED and resistor to the 5V and GND pins, or use an influence button with a inbuilt LED
