rain or shine solar charger - storage battery systems

Have you ever thought about providing a waterproof, lightweight portable solar charger for small electronics?
Whether you're a backpacker, a survivor, or just to protect the planet so you can enjoy it outdoors for a longer time, this is your project.
About a month ago, I had an 8-day backpacking trip at Shenandoah National Park.
I have arranged a friend to meet me.
Supply halfway.
Unfortunately, I was with a group of quick people, 27 miles from where we arranged to meet.
Luckily I took my phone with me and the phone usually has about a week of standby time.
Unfortunately, far away from civilization, the signal is much weaker, so in the case I don't know, I only have about a day and a half of standby time in this case.
I found this on the third day.
I started thinking about a recyclable solar charging solution.
I did manage to call her on my phone, but in a park that's not too busy, things might really get out of control.
Until the sixth day, I had a great time when I met real backpacking travel weather: Thunderstorms and cold, heavy rain.
When I got home, my digi-
Cam's in the water.
It works mainly, but sometimes it doesn't turn on or off now, and the LCD has cloudy water spots, even though it's in a self-sealing bag in my bag.
I started thinking about the lightweight waterproof electronic case.
Then I started thinking, "Hey, I can do these two things at the same time!
After 9 prototypes, this is the "solar charger" I have ".
"In addition to being useful for backpacks, this charger comes with a parachute buckle so you can hang it on a messenger bag or hang it on a window in the kitchen.
It takes about ten hours to charge a typical phone, but it's a storage charger, so you can put the charger in the sun, collect energy during the day, and then plug in the battery hone at night, charge from the stored energy.
This is a fairly complex project that may expand your sewing skills or electronic skills, but the result is well worth it.
If you want to skip it all and simply buy this, Etsy link is sewing half of the item to make a waterproof zip pouch, slightly larger than the flexible solar cells we will use to power it.
Bags are made mainly of silicone-
Dip-proof tearing nylon called SilNylon.
This is a lightweight, completely waterproof material that is becoming more and more popular in the backpack world.
You need the following material, I purchased it from www. thru-hiker. com. SilNylon, 6.
5 "x 13" 3 waterproof continuous coil zipper, 5 3/8 "3 zipper pull1/2" nylon strap, 6 "2 1/2" parachute bacx 100% artificial thread. (
Cotton/get in trouble! )
Cut a rectangular nylon 6 first. 5" x 13.
Seam mark "1/2 from long edge and 1/4mm from short edge.
Next, a continuous coil zipper is cut to 5 3/8 long.
Open it from one end of about 2 "and insert the zipper.
Pull the zipper to the middle of the zipper.
Stitch at the end of the zipper on both sides as shown to prevent the zipper from pulling out.
Before we start sewing, here are some quick notes on using SilNylon: I found very small stitching, about 20 stitches per inch, to work best.
Avoid using pins as much as possible, because to be waterproof, you need to seal all the seams and pins.
One very good thing is that it doesn't seem to wear at all due to the silicone dip that connects the threads together.
It's hard to feed you through your machine because it's slippery and it gets stuck with cotton/Poly threads.
OK, we will connect the zipper and form a flap that covers the zipper.
Its structure is very similar to the flight of a pair of trousers.
Remember, when everything is done, we want the shiny side of the zipper to face the outside.
First, center the zipper along an edge, Shine Down, and sew at 1/4 of the edge.
Next, fold the fabric 1/4 "through the zipper and run the thimble as shown.
This will form flaps that cover the zipper.
Next, open the flap stitched at the top and fold the fabric back in half so that the opposite edge is right behind the shiny zipper.
This will form a fabric ring.
Sew the other side of the zipper on the fabric.
The next step is to roll/fold the fabric so that the flaps are flat and cover the zipper, and the edges of the flaps are aligned at the edges of the fabric ring. We're inside-
At this point.
Use a pair of pins through the external seam allowance, because alignment here is critical.
Once everything is recorded correctly, press the creases with your fingers on the top and bottom of the fabric.
After everything is aligned, stitch the sides of the fabric to create the bag.
Start with the normal stitching of the black layout line we made in the first step, and then fold the excess fabric in half and the thimble.
This will make the seams inside the 4 layers thicker, which is important because these are the seams we will connect the batteries and electronics to later.
You should have one now.
Bags that look like photos.
It's time to check your work.
Open the zipper and reverse the pouch through the zipper opening.
You deserve 5 points in the end. 5x5.
5 "bag of hood with cover zipper.
If it looks right, as shown in the figure, put a 1/2 strap on the top two corners.
Because that area is 6 layers thick, not two layers thick, so sew out the current inside.
Now, tie the buckle on the strap and you can sew! Use a silicone-
Seam sealing device like Sil
Seal all exposed seams and stitching.
If you are not well sealed enough, your electronics will get wet and it will be a very bad thing (TM)
Once the sewing machine is dry, pack up your sewing machine and take out your soldering iron and multimeter, it's time to make a solar charger!
There are four main subsystems of solar charger.
It will take me a few minutes to review.
If you care more about "hot make" than "why it works", feel free to skip this page as it runs a bit long.
Solar cells.
The battery we use is flexible, thin
Plastic film battery.
They turn the sun into electricity.
In our example, our solar energy array outputs 3 volts and 150 mA in case of sufficient sunlight, while the voltage and milliamperes output in cloudy, hazy conditions.
The voltage and current provided by the battery are variable, so we need a more useful form for storing energy.
We need batteries for this.
We really wanted to hang the solar cells on the phone and call it a day, but that didn't work because they couldn't output enough instantaneous power a lot of the time.
Therefore, we will store solar energy in intermediate batteries that can provide high power.
Solar controller.
The circuit detects when the battery stores useful energy and turns on the phone's charging regulator.
It then monitors the amount of energy in the battery and turns off when the battery runs out. The DC-DC converter.
The solar system operates at variable voltages between 2 v and 3 v.
To charge the battery, we need a regulated 5 v DC.
This is by using DC-
A dc converter, in this case, a light-duty universal converter called AnyVolt Micro.
When I first envisioned the charger part, I planned to do this in an easy way: the solar panels power the regulator and the regulator charges the battery trickle.
Unfortunately, Motorola thinks it's impossible.
My Motorola V325 phone needs at least 100 mA of the charging current, otherwise it will constantly turn on and off the charging circuit.
This will actually run out of battery very quickly instead of charging it, which is the opposite of what we want.
In case of plenty of sunlight, the solar cells I use provide 3 v and 150 mA when wiring in parallel.
This is not enough to maintain a 100 mA charge current at real current
In the world, we have cloud coverage, tree coverage and time of day to deal.
This is exactly the same problem as full-
Solar power generation systems must respond: peak power demand often exceeds the capacity of solar cells.
We will solve this problem in the same way: use the battery.
In this case, I have used two AAA NiMH batteries in a row.
Solar cells charge these batteries at any time through diodes.
The power output of the solar cell is moderate enough that we do not need to add any other circuit to prevent the battery from overcharging.
However, we need a circuit that starts charging the phone when the battery is charged and stops charging the phone when the battery is exhausted.
This will prevent problems with bicycles
For example, the battery will charge for 20 minutes at 100 mA until it reaches a charging state high enough to provide considerable energy for the phone.
Then the phone will be sent from the battery, 250 mA (
The actual charging current depends on how low the battery power of the mobile phone is)
10 minutes, then turn off the charge within the next 20 minutes as the battery runs out until the battery is recharged.
In this way, even if the solar cells cannot continuously output enough power, we can charge the phone with an acceptable charging current.
One advantage of having a battery in the system is that you can put the solar charger outside or in the window, collect energy during the day, and then charge your phone with the stored energy at night after the sun sets.
This makes it possible to use a solar charger as a daily phone charger instead of an emergency or shutdownthe-grid use only.
Another benefit of having a battery is that this means that the solar charger can be used as a solar battery charger for AAA batteries.
This is useful if you carry a digital camera running from AAA cells.
If you need an AA battery, use the AA battery stand instead of the AAA stand in the instruction manual.
The last good thing about this system is that in an absolutely urgent situation, for example, after an alien invasion obscures the sun, you can replace the rechargeable NiMH battery with a disposable alkali, and charge your phone from them.
In most cases, you never need this ability, but if you have to get in touch with the president about one of the alien's weaknesses, it may save the planet.
The charging controller is the core of the system and unfortunately it is the only part that is not turned offthe-
So we have to make a shelf product.
It is not made of standard radio shed parts because its voltage is very low and requires good accuracy.
If you don't feel like doing one after reading this part of the instructions, don't despair.
I made some extra stuff and put it in my etsy store. etsy. com.
You can also order all components-
Hole variant and build the circuit on perf-
If you want.
Just make sure to use 1% resistors.
The first step is to collect all the components.
The following is required: PCB components (
Parts Expresspartsexpress.
Com is a good source. )Pre-
Sensitive single-sided copper clad plate, at least 1 "?
SquareDeveloper is a drill bit for aboveFerric chloridsmall (1/32 or so)
Transparent film :(www. digikey.
Com will be the standard place here. )
1 op amp MCP6002-I/SN-
ND1 dual AAA battery stand with lead BC2AAAW-
ND or radio shak1 shottky diode MBR0540T1GOSCT-
568-1 Zener diode3779-1-
ND2 100 k ohm 1% 0603 month 18 k ohm resistors 1% 0603 months resistor1.
Month 1 k Ohm 0603 month resident 1.
9 ohm 1206 resistor 1 MOSFET FDS6898ACT-
The MOSFET has to be fully turned on by 2 v in order to work, so make sure you want to replace 1 AnyVolt micro universal DC-DC converter (
Not provided by Digikey)MP3-MP3
Charging plugs for mobile phones or other devices.
If you have to get in touch with the president about one of the alien's weaknesses, it may save the planet.
Once you 've collected all the parts, the first electronic step is to etching the board with the artwork that comes with it.
This is an image of 600 DPI and should be printed to about inches.
There are many instructions and other Internet instructions on how to etching the circuit board.
Here is a simple overview.
Print artwork on transparent film. 2.
Remove black-
Remove the film from the copper cladding and place the transparent film on the top. 3.
Press the transparent film on a copper wrap plate with a piece of glass or plexiglass.
This is important for getting a good definition. 4.
Show the board
5 minutes 6 inch away, 60 w desk lamp seems to work but I prefer 90 seconds for 500 W halogen lamp.
Once you have developed the PCB, put the plate artwork in the chlorine iron tank.
An hour without heat or bubbles is about the right time, but check regularly.
After completion, rinse with water and then expose to light again without a mask and peel off the anti-light with the developer.
Sand or cut off the excess material but leave 1/4 on one side.
Drill the hole out with a 1/32 bit.
In addition, as shown in the figure, drill a series of holes in the excess space.
In the next step, we will use it to stitch the regulator to the bag.
Weld components according to images. The left eight-
The lead assembly in the image is the MCP6002 op amp, right eight-
The lead assembly is the FDS6898A MOSFET.
The resistance is 100 k, 16 from left to right. 2k. 100k, 5k.
The left diode is Schottky and the right diode is standard or Zener diode.
There are several ways to weld surface mounting assemblies.
A good option is to melt a drop of wire solder on each pad, then fix the assembly in the appropriate position with tweezers, and use the iron core to move the solder up to meet the assembly.
A very good tip and a soldering iron with temperature control made it all a bit smoother.
A better option would be to place the solder paste on each pad using a solder paste syringe and then heat the entire plate with an air pencil or a hot gun.
The circuit works as a comparative circuit with lag.
If the output of the comparator is high, the FET is turned on, and the FET turns on AnyVolt Micro, which charges the phone from the battery.
Turn off the FET if the output of the comparator is low, turn off the regulator and stop the phone charging.
This allows the solar cell to charge the battery.
If the output of the comparator is high (
Battery charge)
Comparator is looking for the battery voltage of 2. 3V.
It will not continue to work until the battery voltage drops below 2.
3 v, then turn off the phone to charge.
At this point, it starts looking for the voltage of 2. 7v.
When the solar cell charges the battery to 2.
7 v, charger on, repeat cycle.
In the normal operation of the connected phone, the battery voltage always rises to 2.
7, then down to 2.
3, then rise again.
How long this takes depends on the amount of sunlight, but the 30-minute cycle seems typical. The 3.
The 9 ohm resistor limits the charging current to prevent overload of the regulator or phone.
Manufacturing and assembling PCB (
Or buy from my etsy store)
Now is the time to connect all the charging system components.
First, Weld AnyVolt Micro to a pad marked with Ro.
Rg and Ri Ro are connected to Vout leads for Anyvolt micro, Rg is connected to Gnd and Ri is connected to Vin.
Weld the battery bracket to the circuit board.
The black battery holder wire is attached to the pad labeled B-.
The red lead is connected to the pad next to it.
Check the charging adapter you are sacrificing.
Usually, one of the wires will have stripes that mark the polarity.
If there is no mark on any wire, mark a wire in Whiteout.
If it is a circular cable, the internal insulation is usually color coded.
Cut 6 to 12 inch cables from the end of the plug-in phone.
Now peel the insulation from the end of the insert wall or car, insert and use a multimeter, read the voltage, and note the polarity.
This is something we will copy with a solar charger, so it is very important to use it properly.
Doing something wrong may cause magical smoke in your phone, and it's expensive.
In my case, the charger outputs 5 v and the wire with white stripes is positive.
Next, we will adjust the solar charging controller to match the charger in stock.
Put a pair of new AAA batteries into the battery box.
I can choose a rechargeable battery with a new charge, but the alkaline battery is OK as well.
Now, measure the voltage between the two top pads as shown in the figure.
It may read about 8 v.
There is a adjusting screw on the side of AnyVolt Micro.
Turn it on until the output reads 5 v, or whatever your device expects.
The adjustment screw is a 22-turn potentiometer and you can't damage it by turning it too far.
To reach the right range, you need to turn the full number of turns at least a few times.
Once the output is correct, weld the charging plug wire to the circuit board.
The C output is positive, and the output of another similar size and shape in the center of the top of the board is negative.
Check the output voltage again because we are at the moment of truth.
Insert your phone when you have verified that the voltage and polarity are correct.
It should register that the charger is connected and start charging.
This will charge from the AAA battery in the stand, so if you use alkali, unplug it after you verify it is correct.
Otherwise, the phone will charge the alkaline batteries, and then they will run out of power.
That's too wasteful.
Welding two long fine lines from the remaining two pads (One is marked as P-)
Like a solar cell.
Electronic products have basically been completed.
Now we have a hybrid!
Now is the time to put everything together.
The first step is to turn everything over and sew the battery seat and regulator on one of the hems inside.
This is done manually through the holes we drilled on the battery box and controller.
The seams are four layers of fabric, connected directly to the snap, so they are strong enough to withstand the weight of the battery and the regulator.
Then two thin wires are run for the solar cell by stitching, and the zipper is connected to the bag at the end with the connected battery box and controller assembly.
This will put the two wires under the hood of the cover zipper and outside the bag.
It's also a good idea to sew the charger patch on the seam.
This will keep some strain on the joint on the PCB.
Connect three solar cells in parallel.
The battery has Silver End labels for the connection, but these are covered with plastic film.
With your soldering iron, melt a small hole in the plastic film anywhere you need to weld the wires.
The plastic film will melt and then the label will accept welding easily.
Remember, you are working on plastic and be careful not to use too much heat.
Also place two welded dabs at the bottom of the battery assembly to connect to the charger wire when time comes.
Measure the polarity of the solar cell output using a multimeter and note it down.
The polarity in the final picture of this structure is correct, but measurement is always a good idea.
Now we will stick the solar cells to the bag.
Run a layer of Sil-
Net around the outer edge of the bottom (silver side)of each cell.
Insert a piece of cardboard into the bag to make a flat rigid surface and then align the cells and place them on the top surface.
It is a good idea to put the batteries above the zip bag, because although they are flexible for solar cells, they are still rigid compared to SilNylon. When the Sil-
The battery has been dried and tested to ensure that the solar cells are well attached.
If so, cut off the excess wire that extends to the regulator and weld the battery to the wire. Use more Sil-
Fix the wire to the net on the fabric-
Getting them stuck with something in a remote area would be a very bad thing.
You built it!
Now is the time to test.
Measure the voltage of the AAA NiMH battery pair you will be using, and then plug them into the battery box.
Write down the initial voltage.
Put the charger in a sunny spot and the solar cells face the sun.
Go for some snacks and tidy up the mess you made.
Come back two or three hours later, take out the battery and measure the voltage again.
The battery should have voltage. 1 to .
2 volts higher than before.
If so, then the charger is charging its internal battery.
If not, please check all connections and wires between the solar panel and the battery box.
Once the internal batteries are charged properly, let them charge in the sun until they reach 1. 4 volts each.
At this time, it is time to test the phone to charge.
Plug in the phone, take a deep breath and hear the reassuring Bloobloobeep, which means it starts charging.
It may display a Zero bar or a charging bar-
Our charging speed is not as fast as the wall adapter, but it doesn't matter.
If the internal battery is charged from the solar cell and the phone is charged from the internal battery, congrats!
You just made a solar charger!
It takes about 10 hours to charge my phone, and unless it's some sort of smartphone, your phone may be similar.
It is also a good idea to test the water resistance of the shower before traveling in case you miss any seams, stitches or gaps.