Living offgrid with small solar system(s)

[Jing Joe]

Hi Guys;

When I first thought about the idea of charging the Lithium battery with the salt water battery, I imagined the erosion of the salt water battery continually taking place so what's the point?

Then got thinking that with suitable design, when the device is at rest, once the charge is max, then equilibrium might happen so there is little or no current produced so the salt water battery has a longer life than first thought???

Then when needed, the lovely low internal resistance of the Lithium battery, its stable voltage (unlike super-caps) and higher stored power, is better for when all the LEDs or the USB outlet is used. Intermittent power use comes to mind but so does relativity, i.e sizes of salt batteries versus Lithium storage capacities = Purpose designed.

If that's what its all about then that's quite clever;- Who would have thought --- A very old generation battery charging the latest generation battery.

BUT, if there was a small solar panel instead, that's a whole lot simpler, and the market is flooded with these already.

But at least the salt water version means you don't take it out in the sun daily, then curse it when it goes flat at midnight, and the salt power production is potentially there all night.

George; your research and enthusiasm far outweighs the occasional "unawareness" of some facts about physics, and you never cease to amaze with what you come up with.

I've learnt so much thanks. I'm not a teacher but there is a well known saying; "those who teach must never cease to learn".

[IMHO]

2.6Wp PV cells cost $1 a piece... while all this talk of batteries charging batteries is maybe fun, it's also kinda pointless when a cheaper, more effective solution already exists

http://www.aliexpress.com/item/Hot-Sale-108pcs-2-4W-Solar-Cell-Grade-A-125-125mm-Photovoltaic-Poly-Polycrystalline-Silicon-Solar/32440572728.html?spm=2114.30010308.3.19.3Tj3Tw&ws_ab_test=searchweb201556_0,searchweb201602_1_10037_10017_507_10032_401_10040,searchweb201603_2&btsid=1efcd2d9-ab8a-4f9b-9eb8-4c23c67fdb46

[Muhendis]

A few posts ago I mentioned a system of PV cells added to a cell phone to prolong the battery life between charges. It strikes me that this is another useful gadget which could benefit even more from such an idea. How about incorporating the PV cells into the lantern in such a way as to feed a bit back into the battery and slow down the discharge rate.

I thought Dickens was good at writing but I do like his battery. Seeing that makes me want to have a go myself.

Edited June 14, 2016 by Muhendis

[George Harmony]

Here are 2 examples of saltwater battery chargers. Also, as posted before the pinoy Salt lamp/charger.

Difference with solar is that you can charge at nighttime also. If you do not need the charger, clean it and it is standby for lifetime. I think such products is a welcome supplement to solar power. Also, easy diy with easy to get materials.

For the bigger satwater batteries up to 600ah 12volt its a challange to find out how one can make it diy with cheap materials (anodes).

Thats what im trying to figure it out.

http://www.techradar.com/news/portable-devices/world-s-smallest-fuel-cell-charger-will-power-your-phone-with-salt-water-1315492

Ps: The led connected to the ice cube is still burning (24hours each day). Immagine i can continiously charge some supercapacitors with it.............???

Edited June 14, 2016 by George Harmony

[George Harmony]

I found a site with all info about the commercial saltwater lamp and hp charger.

http://backerclub.co/project.php?id=4065

A single inexpensive PowerRod provides run times of 250+ hours - the approximate equivalent of 85 conventional AA batteries - at a fraction of the cost. While were all for the latest advances in solar technology, in terms of portable power, the PL-500 offers significant advantages. It generates power 24 hours a day, day or night, in any weather, under any conditions. It's rugged and lightweight, with practical & reliable construction. Stored dry the PL-500 has a virtually unlimited shelf life of 25+ years. Activated with salt water it provides instant light & power output. Sediment from EC-250 EnergyCells is non-toxic and eco-friendly. Its perfect for camping, outdoor activities away from mainstream electrical grids or as an emergency light during power outages.

[Crossy]

Ps: The led connected to the ice cube is still burning (24hours each day). Immagine i can continiously charge some supercapacitors with it.............???

V & I please G.

EDIT

Measure the voltage across the LED whilst it is operating (V).

Measure the current flowing through the LED whilst it is operating (I)

The meter in your photos is quite capable of making these basic measurements.

[George Harmony]

Ok @crossy. Il do it later today cause im outside controlling the workers.

3 days ago i made this with sand, bit cement, salt and cleaning liquid for toilet.

According to diy-ers who made cement batteries you have to wait few days.

I measure 0.8-0.9volt and this DcMA...What does it mean??

[Muhendis]

I measure 0.8-0.9volt and this DcMA...What does it mean??

What it means George, is that by some fluke (?) you are able to get to grips with producing something that passes as electricity but you don't have any fundamental understanding of how to measure it.

Dc mA is translated into Direct Current Milliamps. You connect it in series with the battery and the LED (or whatever load you are using) and you can measure the current flowing in that circuit. Since you are using an analogue meter take care to connect the meter the right way round or the needle will try to go backwards to less than zero. You also have multiple scales on the meter. Each scale relates to the writing around the switch.

I am praying to the god of electronics that he doesn't send a bolt of lightning in your direction.

[George Harmony]

Ok. Then the direct current of this cement battery = almost 2.5 higher than that Dickens Air battery....amazing is it not???

Maybe its logic since i did not put saltwater or other chemicals in that dickens battery, only water as electrolyte.

This german guy can lightup a rather strong led(s) with one small cement battery. Look also his other vids. Very interesting.

Edited June 15, 2016 by George Harmony

[IMHO]

@George:

The only truly meaningful spec for any battery is watt hours. For us to understand that, we need to know both the voltage and current the battery can support over a given time.

At this stage, we'd be happy just to understand how many watts at any one time these batteries you're playing with can support. We can get in to time based measurements if one of them looks remotely promising.

So for now, just to satisfy everyone's curiosity, could you at least give us both Volts and Milliamps readings?

Here's how:

[Crossy]

Whilst you're at it G. learn what the mirror on your multimeter is for (no, it's not to make it look pretty), that would also show you how to properly take photos of your meter readings.

[George Harmony]

Ok ok..got it....i will give a detailed report after i made a descent one.

Till now i just replicate something in a minute or 2. Cables, wires, rods etc..are not connected well.

Coming back to the dickens battery. If one with only water as electrolyte (see pict) can give lets say only 50ma and i make 10 of these i can get 1.5 volt and around 500ma. Right or not??

With only water as electrolyte it will last long long time i think. Ive seen examples of joule thiefs which can lightenup SOME bright leds with low voltage. So, in theory its not so difficult to make a bright diy lamp with diy battery with only water (not salt water) as electrolite.

Lets say total leds with joule thief is 3watt. How long can it burn with 500ma 1.2-1.5 volt??? Can anyone answer please.

[Crossy]

Sorry G. what is an "ma"? There is no SI unit with the symbol "a", "a milli-aardvark" perhaps.

Assuming you mean "A" (Amps), 500mA @ 1.5V is 0.75 Watts. A 3 Watt LED cannot burn at all on such a supply.

IF you were to be able to store the 0.75W for 24 hours then your 3W LED would run for about 6 hours off the stored energy (assuming 100% storage efficiency).

And, before you say "you know what I mean" learn the difference between a "mA" and a "MA". One is 1,000,000,000 times bigger than the other, do you know which is which?

[George Harmony]

With a 1.2v 500mA battery and i use this 4leds each 25mA with this joule thief setup can i burn more than 5 hours??

Btw my not so well made dickens battery with water only gives indeed around 50mA.

I think with better setup and perhaps longer rod one can achieve indeed 100mA like the pict said. If i add saltwater or other chemicals perhaps more current but it will "eat" the magnesium faster.

[Muhendis]

Crossy. An ma is "Master of Arts"...........

You might enjoy what the future may bring. Read on.........

Once again though there is little information of power capabilities.

Scientists have been working on nanowire batteries for some time. Nanowire batteries, with their wires thousands of times thinner than a human hair feature a large surface area for the storage and transfer of electrons. There was only one small, but fatal, flaw, the wires were fragile. They quickly grew brittle and cracked and their effective lifetime was even shorter than conventional Lithium-ion batteries.

The researchers beat this problem by coating a gold nanowire in a manganese dioxide shell and encasing the assembly in an electrolyte made of a Plexiglas-like gel. These encased wires, according to the study leader, UCI doctoral candidate Mya Le Thai, were cycled up to 200,000 times over three months without any loss of capacity or power and without fracturing any nanowires. A 24-hour charge smartphone battery with that kind of lifetime would be good for more than 500 years.

[Muhendis]

George. Did you get your information about the Dickens battery here? http://peswiki.com/index.php/OS:Stephen_Dickens_Magnesium-Water-Copper_Battery I notice that the claim is for only a few mA of current so If you can do better then you should contact the web site and tell them about it. It seems that you have a lot in common with this Steven Dickens fellow.

[George Harmony]

George. Did you get your information about the Dickens battery here? http://peswiki.com/index.php/OS:Stephen_Dickens_Magnesium-Water-Copper_Battery I notice that the claim is for only a few mA of current so If you can do better then you should contact the web site and tell them about it. It seems that you have a lot in common with this Steven Dickens fellow.

Dont know what you mean? I read there:

3.The rod is wrapped by 1/2-inch foam insulation. The assembly is immersed in water (with no added electrolyte) up to the top of the foam. It produces around 1.5 V and 20-100 mA continuously.

[George Harmony]

Im just beginning to learn about all of this. Perhaps there is misunderstanding here.

Ive tested some (salt)water batteries.

Suppose with some of these batteries connected i can achieve for example 1.5volt and enough amps to lighten up the 12v 5watt lamp with the joule thief as per attached pict. If its possible how long it will burn? It will always burn if you feed CONSTANTLY with the electrolite. Or did i understand it wrong????

For example, if the dickens battery get dry i put some water and the amp+volt immediately rise till the max per cell, e.g. 1.5v 50mA.

Remember my water filter idea?? I will then constantly circulate with the required electrolite, water or saltwater depending on the type of battery.

So when somebody claims he can burn a certain lamp with a water battery and it burn only 10 minutes it means that that he have to refresh the electrolyte and it can burn again 10 minutes. Continiously dripping the electrolite into the battery it will always burn.

I can be wrong.......

[Crossy]

Btw my not so well made dickens battery with water only gives indeed around 50mA.

No it doesn't. Learn to read your meter!!!

And, you are measuring the short-circuit current, not really a valid test (Note- Don't try that with a proper AA cell, you will fry your meter).

The 2N3055 based Joule-thief will be very inefficient, look for more modern circuits. A 5W LED powered by a Joule-thief will draw x Amps from a 1.5V cell.

Work out x and see the futility of driving anything more than a few hundred milliwatts from your simple batteries.

Have a look on AliExpress for some properly designed boost drivers (Joule-thief), something like this may do the trick if you can get a decent amount of current (maybe charge supercaps to 12V) http://www.aliexpress.com/item/xml-3c-warm-light-Lamp-beads-lights-wide-voltage-3V-12V-bike-light-headlamp-drive-Circuit/32671668983.html?spm=2114.13010308.0.50.tUpIFl

I could design the electronics for you, but would you be able to build it? And of course, there's no fun in having it done for you

[Muhendis]

Btw my not so well made dickens battery with water only gives indeed around 50mA.

No it doesn't. Learn to read your meter!!!

And, you are measuring the short-circuit current, not really a valid test (Note- Don't try that with a proper AA cell, you will fry your meter).

The 2N3055 based Joule-thief will be very inefficient, look for more modern circuits. A 5W LED powered by a Joule-thief will draw x Amps from a 1.5V cell.

Work out x and see the futility of driving anything more than a few hundred milliwatts from your simple batteries.

Have a look on AliExpress for some properly designed boost drivers (Joule-thief), something like this may do the trick if you can get a decent amount of current (maybe charge supercaps to 12V) http://www.aliexpress.com/item/xml-3c-warm-light-Lamp-beads-lights-wide-voltage-3V-12V-bike-light-headlamp-drive-Circuit/32671668983.html?spm=2114.13010308.0.50.tUpIFl

I could design the electronics for you, but would you be able to build it? And of course, there's no fun in having it done for you

Actually, Georges measurements do supply some useful information. It tells us that the internal battery resistance is too high to be of any use beyond a few mA.

[George Harmony]

I made the dickens battery more wet and pict 1 shows the results, short circuit current (DCmA on 25)

Imagine you make a dozen like the setup in pict2, instead of mudbatteries dickens batteries ... with only A LITTLE BIT water as electrolite.

Edited June 16, 2016 by George Harmony

[Crossy]

So G. what currents do your photos show?

and what do you calculate the internal resistance of your batteries to be?

The multi-cell thingy in photo 2 has 54 cells in parallel, what would you calculate the available short circuit current to be?

We still haven't got any figures for energy (Watt / hours) form your experiments.

You have working batteries and the measuring kit, let's have some usable numbers (measure the LED voltage, LED current and time of operation).

[George Harmony]

@crossy,

I can order this online at an indonesian store. Do you think its a useful driver to use with water batteries??

LED Driver for 3 x Cree XML

Input 3 - 18 Volt

Output 3.7 - 4 Volt

Output curent 7 Ampere.

SIZE BOARD 30.5MM

Ps: Above pict shows more batteries indeed. Just an idea of a design for 12 water batteries (or more or less)

Edited June 16, 2016 by George Harmony

[George Harmony]

We still haven't got any figures for energy (Watt / hours) form your experiments.

You have working batteries and the measuring kit, let's have some usable numbers (measure the LED voltage, LED current and time of operation).

Perhaps im again very stubborn. Excuse me for that. In my previous post i tried to tell that if i can burn a lamp with water batteries, why i have to know the Ah?? It will continiously burn when i continiously drip with the electrolite. Its handy to know how many batteries i need to burn a certain lamp i want with or without joule thief.

Also handy to know how long will the anode last?

Or am i wrong to think this way??

I can imagine during the day i clean the batteries (automaticly) and when its dark the dripping with electrolyte will start till i sleep.

[Crossy]

OK if you're keeping secrets...

Don't expect more assistance from this end.

You ask many questions, but don't provide the information for us to help you answer them.

For example "Its handy to know how many batteries i need to burn a certain lamp i want with or without joule thief.". Without some V and I data from your battery it's completely impossible to answer this.

[George Harmony]

Before i posted:

Here my expirement/replicating "Dickens air battery" with the survival magnnesium kit. Gives about 1.2v. On top of the table just arrived, (long)carbon rods for hopefully more amps with another type of battery

I try to measure the DCmA, it seems thus that i measured the short circuit.

I just made another one. It seems that it takes a bit of time to get the foam completely wet (absorbtion). But i measure immediately a voltage of 1-1.2volt with a little bit of water.

Its for sure that i can get 3v+ with 3 or 4 of these dickens battery. Once the foam absorbs water the current rise. Its then also easier to drip continiously.

Its indeed interesting to know before hand the Ah untill it dry out and/or the Ah untill the magnesium is "kaput" when you drip it with water continiously. Like the example of a commercial saltwater version says: "one single power rod gives 1.5v 50Ah"

Since this dickens battery works only with water it will i think last very long time especially when you reguarely clean it. With saltwater it will "eat" the cathode and anodes, like i already see in my icetray. The galvanised screws begins to corrode. ?

Thats why the dickens battery is i think better and im now convinced that the specs as given on the link posted by muhendis is accurate if you make exactly the same one. It can give 1-1.5 v and 20-100mA continiously.

Edited June 16, 2016 by George Harmony

[Crossy]

Despite my above post I hate seeing people struggle.

George, read and understand this http://www.radio-electronics.com/info/t_and_m/analogue-multimeter-voa-vom/how-to-use-using-analog-meter.php

Then read my signature.

And post:-

• Open circuit (no load) voltage
• Short circuit current
• If you have a load that the cell(s) will run post the voltage and current from the load.

With this information we can answer many of your questions. Of course, if you don't, we can't.

[Muhendis]

Despite my above post I hate seeing people struggle.

George, read and understand this http://www.radio-electronics.com/info/t_and_m/analogue-multimeter-voa-vom/how-to-use-using-analog-meter.php

Then read my signature.

And post:-

• Open circuit (no load) voltage
• Short circuit current
• If you have a load that the cell(s) will run post the voltage and current from the load.

With this information we can answer many of your questions. Of course, if you don't, we can't.

You beat me to it Crossy.

[IMHO]

Despite my above post I hate seeing people struggle.

George, read and understand this http://www.radio-electronics.com/info/t_and_m/analogue-multimeter-voa-vom/how-to-use-using-analog-meter.php

Then read my signature.

And post:-

• Open circuit (no load) voltage
• Short circuit current
• If you have a load that the cell(s) will run post the voltage and current from the load.

With this information we can answer many of your questions. Of course, if you don't, we can't.

It's a pity there's a guy that so obviously likes to experiment, but seems unwilling to learn - especially when there's some pro's very patiently standing by to help him.

[Jing Joe]

Despite my above post I hate seeing people struggle.

George, read and understand this http://www.radio-electronics.com/info/t_and_m/analogue-multimeter-voa-vom/how-to-use-using-analog-meter.php

To Crossy,

Good article/s sincere thanks.

"You can learn something new every day and if you don't --- you are not paying enough attention"