Updated Jul-13-2010

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 has been running on a reconditioned battery since Jul-8.  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, that the results would be 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 in:

• Wireless headphones

• LED flashlight

• Clocks

• Cordless laser mouse

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  But 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 full recharged.  They prefer partial discharges with frequent recharges.

Exercising Batteries – My Personal Notes… Work-in-progress

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 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

From the summer of 2008 when I started to get serious about solar panels.

I chose to use aluminum angle to construct my solar panel frame. Video below…

I cut through the aluminum angle using a hacksaw.

I drilled the holes into the aluminum using a drill press and a hand drill.

To protect the steel pipe from the elements, rust, and corrosion, I sprayed it with a cheap, $1 can of black spray paint.

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Conduit connects to the solar panel and how the pole is concreted into the ground with rebar.  Video below…

How do you get conduit out of the boxes anyway?  I think I spent way too much time trying to figure it out, trying to find the end of the conduit so I could pull it through the box.  It may be easier to cut the box all the way open and remove the entire coil of conduit from its box.  If you plan on using all the conduit for one job, why try so hard to preserve the box?

Solar panel is mounted to top of pole and locked with a chain. Solar panel can rotate on pole and aim at the sun. To demonstrate that the panel is producing power, it is used to charge a portable 12V battery and air compressor. The air compressor then inflates the tires on a bicycle.  Video below…

Using Wolfram Alpha, you can find your longitude and latitude coordinates on Earth. Wolfram Alpha also has average wind speed data for your location. You can get weather forecast data to help determine when the best times might be for your wind turbine.

How do I find my latitude on Earth?  See the video below to see:

Lock up your solar panels to prevent theft

These panels cost a lot of money and they would make an easy target for a thief to steal for some quick cash.  An article at insidebayarea.com documents how a guy climbed up on the roof of a school at night and stole $70,000 worth of solar panels and then attempted to sell them on Craigslist.  We need to make more of an effort to protect our investments in off-the-grid power.

Here is one idea for securing panels that I am implementing using locks.

Drill a hole in the solar panel frame to attach a lock.  Then drill holes in a pole concreted to the ground.  Attach locks with a chain to make it harder for theives to take the panel.

The drill bits are titanium coated.

Drill press was used to drill holes into a steel pipe.

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.

How to fix solar light

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.

Electrolysis

To measure the power output of the small solar panel built onto these lights, I used electrolysis.  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 electrolysis?  How many volts and amps does electrolysis require?

As shown in the video above, electrolysis 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/2009/11/03/combiner-box-for-solar-and-wind-to-charge-a-single-battery/ http://www.elperfecto.com/2009/11/03/combiner-box-for-solar-and-wind-to-charge-a-single-battery/#comments Tue, 03 Nov 2009 19:58:03 +0000 Earl http://www.elperfecto.com/?p=433 The video below shows how to make a combiner box to allow solar panels and a wind turbine to charge the same battery.  Also shown in the video: How to make an extension cord out of spare CRT cables and heat shrink.

This combiner box could also be used for other power sources, like combining thermoelectric generation and solar panels.

Idea for box came from the video below.

I added Schottky diodes to the combiner box to make sure that current flows in one direction.

Was driving through Texas and came across an unexpected sight. Spotted wind turbines and solar panels outside Wal-Mart and Sam’s Club in McKinney, TX. I was really surprised to see them in such a public place and got the camera out so I could share with you guys.

In this video: 2 wind turbines, anemometers, and solar panels. The turbine makes a hypnotic sound.

The Wal-Mart store is located at:

2041 Redbud Blvd
Mckinney, TX 75069

(972) 542-9585

Bing Maps was used to show location of store in video and below…

Click image to enlarge Bing Maps view.

I checked the location with Google Earth first but the images were so old that Google Earth showed bare ground where the Wal-Mart was supposed to be.

Click image to enlarge Google Earth view.

Bing Maps actually has more up-to-date images from the bird’s eye view as of this post.  Yes, I am surprised that Microsoft has improved so much lately.

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The large turbine produces 50 kW.  The expected annual power production is 80 MWh.

The smaller turbine is a 1 kW stand-alone turbine which powers the Wal-Mart sign.

There is just one other such store in the US and it’s in Aurora, CO.

[ Source of some data in post and in video:  renewableenergyworld.com and ashrae.org ]

Charging a Cub Cadet lawnmower 12V battery with a solar panel and Sunsei charge controller.

The lawnmower battery will die during the winter months and will not start the mower in the spring unless it is charged. Charging the battery on a beautiful winter day helps ensure the mower will start up this spring.

Click image below for video…

I use my media player, a Creative Zen Vision W, to listen to podcasts and occasionally I’ll watch a video on it or let my kids watch videos on it. The other day the battery was dead and I decided to use my small solar circuit to charge it up.

This solar system completely charged the Zen media player. Here’s how it is connected.

Two small panels are outside in the sun, with the cable leading into the house.

The cable connects to a charge controller. The charge controller safely feeds the solar power into a 12V deep cycle battery.

The power from the battery goes to a DC-AC inverter, producing 120V AC. The AC inverter is connected to my multimeter so I can see how much current the Zen is pulling during charging. You can see that the Zen AND inverter together are pulling 0.88A.

You can see in the above image that the white AC adapter is plugged into an AC inverter, taking 120V AC to the media player to charge it up.

Media players are one of many small devices that can be powered or charged using modest solar panels.