Scrap CRT TV lying on the ground produces electricity as it rusts.

I connected a Joule Thief to the scrap TV lying on the ground and had some luck generating a tiny amount of power from it.  This method of generating electricity uses the principle of a Galvanic cell.

With this setup, I was able to capture enough energy to light a white LED.

The LED blinked when connected to the scrap metal and a Joule Thief.

The goal of this experiment was to prove to myself that discarded metal can make electricity as it rusts, corrodes, and oxidizes outside.

VIDEO

Questions

Where does that energy go if I’m not connecting a circuit to it, but the metal is still being oxidized?  (One guess:  The energy goes through water vapor in the air to complete the circuit, acting like electrolysis, making Hydrogen and Oxygen?  This would be more likely on humid days and when it is raining.)

Other Ideas

• Add more capacitors in parallel to see if I could store up more power to increase the duration of the LED blinks.

• Add a photosensor so that the circuit turns on only at night.  The circuit could store the energy during the day and use it up for a short duration of power at night.  The photosensor could be a photoresistor or phototransistor.

• Instead of using the ground as the electrolyte, use a container of salt water with part of the TV making contact with that liquid and the other metal dipped into the liquid.

Related Posts

More on the Joule Thief shown in the video:  Rubber Band Joule Thief

How to make a Joule Thief (includes circuit diagram)

More on how I salvaged parts from the broken TV:  Salvaging electronics from a broken TV

The results of using hydrolysis to help clean the burned pot.

I wondered if hydrolysis would help clean this mess.  A 12V solar panel supplied the power.

Hydrolysis then produced Hydrogen gas bubbles on the surface of the metal pot, helping to loosen the burned debris.

VIDEO

I find it interesting that one terminal gets oxidized and ruined at the expense of cleaning the other terminal.

Oxidized positive terminal from this hydrolysis experiment.

Close-up of same terminal.

Rust as Fertilizer

Rust is a form of Iron and is taken up by plants and nourishes them.  Some people buy fertilizer with Iron in it.  Plants gain a richer green color from Iron.  One idea I have is to purposely oxidize scrap metal and pour the rust as a supplement into my garden beds or compost pile.  It seems better than throwing the scrap metal into a landfill where it is wasted.

Conclusion

My observation is that about an hour of hydrolysis is sufficient to loosen the burned food so that the rest can be scrubbed off with ease.

Updated Jan-02-2011

Surging Batteries

I save my defective batteries in a box.  These batteries will not charge any more and have a voltage of 0 Volts.  A 12V solar panel, which  provides a relatively safe voltage, brought these batteries back up to a normal AA voltage with just a few seconds of surging!

VIDEO

After surging the batteries, as shown in the video above, I looked for an application where I could use just a single battery to provide power.  In order to test the capacity of the reclaimed batteries, it seems best to test each one on its own and not mixed with other batteries.  There aren’t many electronics that use just one AA battery, but here are some:

• Flasher LED’s

• Newer LED flashlights  (I don’t have one of these, though)

• Clocks

This clock uses a single AA battery for power.

I have a couple clocks that each use a single AA battery.  So I popped reconditioned batteries into them and they are working!

VIDEO

The clock above ran on a reconditioned battery from July 8 until August 5, so almost one month.  The interesting point here is that the batteries used to be at 0 Volts and would not charge up, so were destined for the trash or recycle bin.  But after zapping them for a few seconds with a solar panel, the batteries are again back to work doing something useful.

Battery Charging after Surging

The results are not perfect.  I waited a couple days after surging before doing anything with these batteries.  The result is that more than half the batteries went back to 0 Volts.  I believe if I had tried using the batteries or charging them right after surging, the results would have been better.

VIDEO

As shown in the video above, since I waited a couple days before doing anything with the batteries, many of them returned to 0 Volts.  I performed the surging experiment one more time and had much better luck with the batteries, as shown in the video below.

VIDEO

The good results continued.  After most of the batteries charged up, many of the batteries became useful.  I am using some of the reclaimed batteries to power:

• Wireless headphones

• LED flashlight

• Clocks

• Cordless laser mouse

• Microcontrollers [ powering a TI Launchpad MSP430 ]

VIDEO

Conclusion

Surging the dead batteries brought many of them back to life and gave them new purpose.  However, they are not good as new and probably have some issues with charge capacity.  But for me, I’m glad to have many of these batteries back to work instead of sitting in a box as scrap.

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Freezing Batteries

I froze a battery pack and saw the voltage of the pack climb from 6.9V before freezing to 8.4 V after freezing.  I did not surge the pack.  Freezing by itself improved the voltage.  The battery pack came from a Spykee robot.

Related post:  Repairing and Replacing Batteries on a Spykee Robot

It’s OK to freeze NiCd, NiMH, and Lithium batteries. I think freezing disrupts the crystals that are causing the plates to short together. After freezing, hit end of battery with soft hammer to break crystals?  [ Source:  ysuusy.com ]

It might not work with Lithium batteries [ source ], although Lithium batteries should be safe from damage even as low as -40C [ source ].

Lithium batteries will not be damaged in freezer as long as they are allowed to warm again before use [source].

A well-written procedure:  Hackaday.

Give a Lithium Battery a New Function

My notebook computer uses a Lithium-ion battery.   This kind of battery typically lasts between 2-3 years.  I have one in storage now after it got too weak to keep the notebook powered for long.  Why do Lithium batteries stop working?  Oxidation inside the battery increases the internal resistance. The oxidation builds up over time and eventually, the cell resistance reaches a point where the pack can no longer deliver the stored energy even though the battery may still have ample charge!  For this reason, an aged battery can be kept longer in applications that draw low current.  [ source ]  So, while my old battery pack might not be suitable for the notebook computer any more, maybe I could use it to light up a few LEDs, power a portable radio, a portable media player, or a micro-controller (like an Arduino).  I’m glad I didn’t throw the battery pack away.  I’ll have to try using that battery pack again for a small application.  First, I have to figure out how to tap into the power connector of a Lithium-ion battery.

Store Batteries at Low Temperatures

Lithium batteries keep their storage capacity better if stored at 0°C and at a 40% charge level.  Some reserve charge is needed to keep the battery and its protection circuit operational during prolonged storage.  [ source ]  This means we could store Lithium batteries in the freezer for improved longevity.

NiMH and Lithium Are Different

Lithium batteries do not like to be fully discharged and fully recharged.  They prefer partial discharges with frequent recharges.

Exercising Batteries – My Personal Notes… Work-in-progress (might update later)

Using an Arduino microcontroller, I exercised some batteries by having them turn LED’s on and off until their voltage dipped below a threshold voltage.

Used this NPN transistor:  ON Semiconductor BC547B.  Data sheet:  http://www.chipcatalog.com/ONSemi/BC547B.htm

The BC547B transistor can handle a maximum of 100mA.  The LED’s I’m using fall below this limit, so this transistor is OK for this application.

My red LED consumes 15mA.

Blinking LED takes up to 13 mA

Blue LED:   up to 65 mA

How to change the batteries on Spykee, the robot.

Spykee came back to life when attached to a 12V portable battery.

In the video below, we hack into Spykee to attach new leads which will later allow for the connection of an external battery pack.  We also connect a multimeter to monitor the battery voltage.  We connect a 12V battery, charged with a solar panel, for testing.  Yes, Spykee works on 12V and could be off-the-grid!

VIDEO:  Verifying Spykee can run on 12V

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Next, we connected a new external battery pack that uses standard AA rechargeable batteries.  Nothing proprietary here.  We made the new battery pack and now Spykee is better than new. His new external AA battery pack has a higher charge capacity than the original pack that came from the manufacturer.  The original pack was rated at 1,800 mAh while my new home-made replacement battery is rated at 2,400 mAh.  The batteries I chose are Imedion Low-Discharge AA batteries made by Powerex.  See how it works in the video below.

VIDEO:  Spykee gets new battery pack with no tether.

Testing the Original Battery Pack

I tried freezing the original batteries that came with Spykee.  That improved the battery voltage, but was not enough of an improvement to get Spykee moving.

Spykee's original 9.6V NiMH battery

The video below shows the freezing process and how freezing increased the voltage of the batteries.

Results of Freezing Battery

VIDEO:  Freezing Spykee’s original batteries and Connecting to Charger

Disassembly of the original Spykee battery pack

When I took the pack apart, I found 2 bad cells and 6 good cells.  The good cells could be used for another project.

VIDEO:  Salvaging Spykee’s original batteries

I put the two bad cells into my battery charger.  One of them charged up.  That leaves me with one cell at 0 Volts.  I plan to surge it with my solar panel.  Spykee’s original batteries will live on in another application.

I found it humorous and couldn’t resist trying to make a remix of it. I wish I could have been in the room when it happened. I also like to experiment with Hydrogen, so I admire this group for trying something new. They also have other successful experiments.

Here’s the remix:

And here is the original video:

To give the experimenters credit, they did come up with some corrective actions to prevent future disasters. Luckily, all is well and they learned a lesson from the experiment.

They said that this fuel cell ran well at 12V, but then exploded when they increased the voltage to 150V.  The wires couldn’t take the extra current, got red hot, and ignited the Hydrogen gas.

Corrective Actions

Use a larger gauge cable, to allow for larger Amp draws without getting hot.

Fill the cell to the top with salt water to lower the amount of combustible gas present in the fuel cell.

Install a pressure release valve.

Perform future testing with an open top fuel cell so that the combustible HHO gas will dilute into air.  This would be best done outdoors, too, to prevent an explosion inside your house.

See more of the HHO videos on RonL2524’s Youtube channel.

Related post:  Electrolysis of water into HHO using solar cells

Hampton Bay Solar Light Reviews

The solar lanterns are made by Hampton Bay.  I see online there are many negative reviews for these lights.  Some of the complaints I also have:

• LED is too dim
• LED won’t turn on
• Not enough illumination
• Battery contacts corrode
• Solar panels darken and become cloudy over time
• Batteries included don’t last long (I replaced mine with batteries having more mA hours)

Here are some excerpts from other reviews on the web:

“I will never by anything with the Hampton Bay name again.”  complaintsboard.com

“Very dim, barely lights. Hard to see at night. Purchased at Home Depot…” complaintsboard.com

“Most lights quit between 10-18 months so if your looking for long term lighting solution, plan on continually buying replacements…”  homedepot.com

“I always get battery contact failure and end up soldering my batteries in.”  thestuccocompany.com

“I purchased a hampton bay solar walk light several weeks ago and it just stopped working.”  askmehelpdesk.com

Cleaning the Panels

The solar panels become cloudy and weathered in the sun.  The panels can be cleaned with rubbing alcohol.

The photoresistor works better if it is clean, so that the circuit knows when the sun is up.  There is no need for the light to be on during the day.  A clean photoresistor makes sure the LED is off during the day, saving the battery power until it is needed at dark.

VIDEO:  How to Fix Solar Lights

A few things that can be done to improve the solar light:

1. Clean solar panel with rubbing alcohol
2. Clean battery terminals
3. Press on capacitors
4. Replace batteries

If your rechargeable batteries are old or not holding a charge, you should change them with new rechargeable batteries.  Want to squeeze some extra life out of those old batteries?  You might try surging the old batteries.

Hydrolysis

To measure the power output of the small solar panel built onto these lights, I used hydrolysis.  I had a few questions:

How much power in Watts do these panels produce?

Answer:  84 mW in winter

Can low power be used in hydrolysis?  How many volts and amps does hydrolysis require?

As shown in the video above, hydrolysis can be achieved with low power.  With only 3.8V and 22 mA, we are splitting water into hydrogen and oxygen!  It doesn’t take much power to make hydrogen.  Looks like anyone can make hydrogen fairly easily.

]]> http://www.elperfecto.com/2010/01/01/solar-light-maintenance/feed/ 0 http://www.elperfecto.com/2009/12/19/make-your-own-air-battery/ http://www.elperfecto.com/2009/12/19/make-your-own-air-battery/#comments Sat, 19 Dec 2009 16:14:44 +0000 Earl http://www.elperfecto.com/?p=535 Make Your Own Air Battery

The video below shows three different electrolytes for a cell.  Which electrolyte will be the best, producing the most voltage and current?

To make your own cell as in the video, get a couple scrap pieces of metal like Copper and Zinc.  The Zinc can be in the form of Zinc-plated steel.

Dunk both metals into a conductive liquid.  This experiment will test three liquids.

1.  plain tap water

2.  water with Sodium bicarbonate, also known as baking soda, which is a salt

3.  water with Sodium Chloride, known as “table salt”

Which one will produce the most power?  Which one will produce the highest voltage and current?  See the video below to find out…

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Spoiler alert:  answer is below.

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Sodium bicarbonate dissolved in water produced the most voltage, current, and power.

tap water alone produced 0.62 V, 0.27 mA

water with sodium chloride produced 0.70 V, 0.50 mA

water with sodium bicarbonate produced 0.71 V, 1.45 mA

Related post:  Tomato Battery

Making a waffle out of sodium acetate trihydrate. This is the same stuff that makes up “hot ice” and heating pads.

How is the liquid made?

I used vinegar and baking soda to make the liquid. Boiled off the water to leave a super saturated salt solution. The salt is normally a solid at room temperature, so when it cools off in the waffle iron, it solidifies.

Vinegar contains the acetic acid.
Baking soda is sodium bicarbonate.
Sodium acetate is the salt formed.

Growing Salt Crystals

Here is a short video I recorded showing how the salt crystals grow quickly when the super saturated liquid is disturbed.

VIDEO - Crystals Growing

The chemical reaction

acetic acid + sodium bicarbonate —-> sodium acetate + carbonic acid

HC₂H₃O₂ + NaHCO₃ —-> NaC₂H₃O₂ + H₂CO₃

The carbonic acid breaks down almost immediately into water and CO₂.

H₂CO₃ —-> H₂O + CO₂

The CO₂ bubbles out of the liquid, leaving just sodium acetate dissolved in water. The sodium acetate binds 3 water molecules to create sodium acetate trihydrate:

NaC₂H₃O₂ + 3 H₂O —-> C₂H₉NaO₅

The sodium acetate trihydrate is what is shown in the videos on this page.

Here is a video that shows how the liquid is made.

Sodium Acetate Trihydrate is a solid at room temp. It melts at 58C (136F). Boils at 122C (252F).

Molding with Salt Crystals

There could be some molding potential for this material. I wonder what interesting creations could be made by pouring this liquid into a mold, as is done with concrete? Care would have to be taken with a mold out of this material, because water would make it dissolve and disassemble. That could be an advantage, however, if you want a temporary mold.

One idea:   make a rain switch.   Place a spring-loaded switch inside a mold of this salt and place the mold outside. When it rains, the salt dissolves, allowing the switch to close. Then, a circuit of your choice could be enabled. So when it rains, your switch would turn on (or off if you wire it that way).

Acid can release electricity from metal.  What is an easy-to-find source of acid?   Tomatoes!

VIDEO

The video above shows how an LED and a buzzer are powered by a tomato battery.  It’s just two different metals dipped into mashed tomatoes.  It even helps charge a AAA battery.

How does this work?

It’s a chemical reaction.  Take any two different metals, separate them with a liquid that conducts electricity, and you have a battery.  Details are included below.

What kind of tomato is best?

Well, green tomatoes are more acidic then red, ripe ones.  So, no need to waste a good eating tomato.  If you grow your own tomatoes, you could pick one early, while still green, and use the acid from that in the battery.

Update on Tomato Battery – 4 Days Later

The video below shows how the Zinc plating was stripped off the metal by the tomato acids.  Also shown is how the LED still lights up, although with less intensity, four days after the tomato battery was constructed.

Video above shows how the AAA battery was charged from the tomato battery.  The AAA battery went up from 1318mV to 1330mV.  While not much, it shows that this small scale experiment could have a practical use.  The energy transferred from the tomato battery to the AAA battery could be used in any application that uses AAA batteries, like wireless headphones or an LED flashlight.

Is the AAA battery being overcharged?

The battery label says it is 1.2V.  If the tomato battery is charging it up to 1.33V, is that overcharging it?  My short answer is “no”.  See the video below for an explanation.

About a week after the tomato battery was constructed, mold was growing on the tomato mix and power production dropped to nearly nothing so I disbanded this experiment and cleaned up my mess.

What kind of acid is in tomatoes?

Tomatoes have a pH of about 4.1.  The lower the pH, the stronger the acid.  To give some perspective, here are the pH values of some other acids.

0.0 Hydrochloric acid

1.0 Gastric acid (in your tummy)

2.2 lemon juice

2.4 vinegar

4.1 tomatoes

5.8 potatoes  source

6.0 urine (Yeah, your urine can be acidic and would work as a weak battery electrolyte!  It is usually more acidic when you first wake up in the morning and turns more alkaline as the day progresses.  The more meat you eat, the more acidic your urine will be.  Vegetarians can have alkaline urine.)

7.0 water (considered to be neutral and not an acid)

From my reading, it appears there are many kinds of acid present in tomatoes:

• ascorbic acid
• chlorogenic acid source
• folic acid source
• p-coumaric acid
• chlorogenic acid source
• salicylic acid source
• malic acid source
• caffeic acid source

What is the chemical reaction in the tomato battery?

In the video above, the tomato battery is initially made with:

• Zinc
• Copper
• acid

The Zinc is the negative terminal, the anode.  The tomato’s acid liberates electrons from the Zinc.

Zn(s)  –> Zn²⁺(aq) + 2 e-

Solid Zinc releases a couple electrons, changing into Zinc ions, which allows it to dissolve into the electrolyte (the water / tomato acid mixture).

Copper is the positive terminal, the cathode.  The Copper atoms attract electrons more than do the Zinc (Zn) atoms.  The electrons that came off the Zinc get sucked into the Copper terminal.

How does the acid help?

An acid’s active ingredient is positively-charged Hydrogen. The acid releases Hydrogen ions (H+) that are reduced to Hydrogen gas (H2), which bubbles around the electrodes.  When I was recording the video above, I did witness bubbles forming around the Zinc plates.  As more bubbles coated the Zinc plates, the battery made less power.  This is because the Hydrogen bubbles prevented the electrolyte from making contact with the metal.  When I lifted the plates out of the electrolyte, the bubbles vanished into thin air, literally!  After returning the plates into the electrolyte, without the Hydrogen bubbles covering the Zinc, the battery gave more power.

By the way, if you could capture this Hydrogen gas, you could generate power from it, too!  Just make a Hydrogen fuel cell and you would get two power sources here.  But back to the battery…

As the current flows, more Zinc ions are dissolved into the tomato electrolyte.  The Zinc is gradually being eaten away.

What is the chemical reaction when salt is added to the electrolyte?

A tomato is actually not necessary, nor is any acid.   Any pair of metals separated by any liquid that conducts electricity will behave as a battery.  The liquid cannot be pure water and the metals must be different.

Most combinations of metals and liquids do not produce enough electrical power to be practical.  The chemical reactions are usually not strong and soon stop producing an electric current.

The first battery was invented in 1800.  In early batteries, someone often had to scrub the metal plates to remove hydrogen bubbles, oxides, and other foreign material to keep the batteries working.  You could still use a battery like this if you didn’t mind the maintenance.

Salt water can be the battery’s electrolyte.  This is called an “air battery”.  However, using an acid generates more power, a higher voltage, and higher current, because it liberates the electrons from both the anode and the cathode.  This means the metals, in this case Copper and Zinc, both get consumed.  In an air battery (or salt water battery), only one of the metals is consumed, resulting in less power generated but also with less materials consumed.

In the acid battery, the acid and both metals are used up.  In the salt water battery, only one of the metals is used up – the other metal and the salt is never consumed.

Related post:  Make Your Own Air Battery

My two kids were interested in the experiment, so for fun, we tried making our own volcano with Mentos and Diet Pepsi. It works!