Living offgrid with small solar system(s)

[George Harmony]

I may yet get to use the super caps I bought as suggested in some posts.

About supercapacitors. This is "cool" with i think also a potentiometer.

???

[Crossy]

And it shows us what exactly G. ?

[George Harmony]

Just a super caps bank idea. I think its very handy if you want to work with supercaps.

Edited June 12, 2016 by George Harmony

[Muhendis]

An innovation for the mobile phone et al is the idea to fit a solar cell into the display which will harvest the displays light and feed it back to the battery. Calm down you over unity boys. It is intended to extend the battery life between charges and will not in any way get into a cycle of supplying a full charge cycle to the battery. Don't forget. PV panels can only convert around 20% of light into electrickery. Would you buy an iPad with a battery life, between charges, of 2 hours or would you buy a similar iPad with a battery life, between charges, of 2.5hours?

George. We don't have access to your thoughts and ideas if you just send pictures of capacitors and LED lights. Please be so good as to tell us what we are looking at.

Thought this might be interesting for some. http://www.power-eng.com/articles/print/volume-120/issue-4/departments/generating-buzz/duke-energy-tests-new-battery-technology.html

[George Harmony]

George. We don't have access to your thoughts and ideas if you just send pictures of capacitors and LED lights. Please be so good as to tell us what we are looking at.

We have been talking also about battery banks and chargecontrollers for solar. I am wondering if for some house lighting supercaps can replace tradional batteries and wether its wise.

There is even a guy who made a chargecontroller for supercaps : http://www.engineeringshock.com/super-cap-battery-kit-x4.html

I now use also some 5watt and 7watt usb lamp/bulbs. If i can burn these for for example 5-6 hours with one charge i will also use a supercap bank. And if i can charge with diy air batteries its for me ideal.

Edited June 12, 2016 by George Harmony

[Jing Joe]

Thought this might be interesting for some. http://www.power-eng.com/articles/print/volume-120/issue-4/departments/generating-buzz/duke-energy-tests-new-battery-technology.html

Wow M that's some battery in the URL you gave us;-

The 100-kW/300-kWh battery uses an Aqueous Hybrid Ion chemistry, including a saltwater electrolyte and synthetic cotton separator--

A bit bigger than George's ice tray battery but looks like things are happening big-time in a unexpected direction.

Who would have thought ---

[Jing Joe]

I may yet get to use the super caps I bought as suggested in some posts.

About supercapacitors. This is "cool" with i think also a potentiometer.

???

For what its worth guys, did you notice the x on the top of the super-caps?

Reckon that the same stress lines as in the ordinary electrolytic caps that give way when the temp rating is exceeded and especially in that bad brand of caps I posted about re someones inverter going off with a bang..

[Naam]

an old friend of mine who is in the windcraft business told me a few weeks ago that Bosch is going to build a 4MW battery.

[George Harmony]

There is someone who makes his own rechargeable batteries or what called supercapacitors that is able to run fans and lightbulbs. For me interesting and perhaps worth to replicate it. He uses aluminium sheet, graphite/carbon and electrolite.

On youtube you can see many examples.

Im really wondering, are they doing this pure for hobby or do they use it for their own need?? Or perhaps they are experimenting for a commercial product...?????

[George Harmony]

A question to you all.

Suppose i have TWO super caps bank. Each can run a usb gadget for lets say 1 hour. If one is empty i want automaticly use the other super cap bank and automaticly charge the empty one for a predefined time. The gadget continues to run with this idea.

How can i realise this? Can i do this with relays?

[Crossy]

How can i realise this? Can i do this with relays?

Relays would be too power-hungry in this application.

Low-power MOS devices are your friends, but don't expect circuit complexity like the three-component Joule-thief.

[Muhendis]

George. The time taken to discharge a capacitor bank is a function of the load which I'm sure you know already. So as long as the load is small the capacitor bank will give you the voltage that you want for a given time. The dc-dc converter which changes the voltage from 2.7v (a full capacitor) to 5v (USB) is going to be quite special because as the capacitor bank discharges its voltage goes down exponentially so the dc-dc converter will need to be still functioning at less than 1.5v input. You might consider connecting the capacitors in series to increase the voltage but this is at the expense of the capacitance value. For example if two capacitors of 1F 2.7v each are connected in parallel you get 2F at 2.7v. If the capacitors are connected in series then you get 0.5F at 5.4v. This is a useful website for you http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html

Edited June 13, 2016 by Muhendis

[George Harmony]

Ok. Thanks for the replies. Suppose i have a cap bank of 10 capacitors 500 farad each which gives a load output of 5.4volt. I can connect one or more usb lamps. Suppose that that capacitors bank is after 1-2 hours is used up. The lamps must be feeded automaticly by a second cap bank. When the second bank is active the first bank must be charge automaticly and when the second bank is used up load comes from the 1st bank and the 2nd must be charged. Its like a loop.

@naam, with a capacitors bank as described does a relay sucks too much power??

There are dc relays available with build in timer, simple ones and fully prorammable more complex ones like attached picts.

[Crossy]

George. Please understand that your 5.4V capacitor bank will only be 5.4V for an infinitely small period of time. Unlike batteries (which are essentially constant-voltage until nearly discharged) the voltage on a capacitor decays as the energy is removed so you will need some electronics to maintain constant voltage to your USB output once the cap goes below 4.8V.

That timer will probably use as much power as your 5V appliance.

[George Harmony]

It was just an idea. When i read your post about the torch i thought, perhaps its possible to make a loop with 2 capacitors bank and run a lamp or a fan continiously cause the charge time is very short and switch the feed between 2 capacitors bank.

Crank for 10 seconds, get light for 20 minutes or so, seems like sensible (joule-thief like) electronics to get the best out of the supercap.

Bigger capacitor + longer crank time = longer light time.

I will orientate for the low power cmos. Thanks.

[George Harmony]

what do the resident learned learning gurus think about my idea attaching a crankshaft to some drinking dunking birds, convert the kinetic energy into electrical energy, amplify the latter by using supercapacitors and drive an aircon compressor?

Perhaps possible to run ac with supercapacitors if i see this and if my "loop idea" can be realised.

Ps: This is the guy who make the torch posted by crossy ( i think)

Edited June 13, 2016 by George Harmony

[IMHO]

I may yet get to use the super caps I bought as suggested in some posts.

About supercapacitors. This is "cool" with i think also a potentiometer.

???

Not sure I'd call these super caps...

To me "super" means caps measured in Farads, not uF

[Muhendis]

George. I like the idea of switching between capacitor banks. I can imagine using some low power voltage comparators and some CMOS analogue switches would achieve this. A regulator is required to supply constant voltage from the capacitors. You don't really want a timer.

[Jing Joe]

In the news;- huge new tourist ship designs are happening --

Propulsion by liquid natural gas, designed to be easily retrofitted to use biofuels or even hydrogen once these technologies become more readily available. Apart from the shape of the hull, its use of ten retractable sails, which, should provide around 10 per cent of propulsion energy in the best conditions. Wind generators and solar panels will provide power for the ship while it sits in port,

[George Harmony]

Just a (existing) new experiment. Why not use carbon brush for small aluminium air batteries. Already have copper wiring :) ... Perhaps few of these can charge a super(uF) cap ...just adding saltwater.

I bought per pack (2pcs) for 5000idr = 0.40usd

I rolled it up in less than 1 minute

Added:

Carbon brush are available in different sizes. In fact its your ready made cathode

Edited June 13, 2016 by George Harmony

[George Harmony]

After posting above post abt carbon brush Courier came with magnesium survival set. But i will use this ofcourse for my further experiments, replicating that battery i posted before which need humid air only

The compass is for travelling with the air battery ?????

Edited June 13, 2016 by George Harmony

[George Harmony]

Here we go again. With 4 little babies carbon brushes burning led with joule thief.

[Crossy]

Which Joule-thief design did you use G?

How much actual power are you generating (LED Volts x LED Amps)?

How long did it run for?

[Muhendis]

George. The time taken to discharge a capacitor bank is a function of the load which I'm sure you know already. So as long as the load is small the capacitor bank will give you the voltage that you want for a given time. The dc-dc converter which changes the voltage from 2.7v (a full capacitor) to 5v (USB) is going to be quite special because as the capacitor bank discharges its voltage goes down exponentially so the dc-dc converter will need to be still functioning at less than 1.5v input. You might consider connecting the capacitors in series to increase the voltage but this is at the expense of the capacitance value. For example if two capacitors of 1F 2.7v each are connected in parallel you get 2F at 2.7v. If the capacitors are connected in series then you get 0.5F at 5.4v. This is a useful website for you http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html

An additional point about the discharge characteristics of capacitors. The exponential discharge curve applies when resistive load is connected across the capacitor. If the load is a constant current then the discharge characteristic would be linear. So discharging into a complex load like a dc-dc converter used for powering an LED would not be quite so easy to predict. The input capacitor of the converter would take pulses of power from the SC (supercapacitor) which would look like a resistive load but in between those pulses there would be very little power taken from the SC at all. The amount of power each pulse would take is dependant on the load. What I am trying to say is that the information I included in the link above is all well and good but does not apply in its simplest form to what George has in mind.

[George Harmony]

Which Joule-thief design did you use G?

How much actual power are you generating (LED Volts x LED Amps)?

How long did it run for?

Each gives about 0.7v. I did not connect with cables/wires just touching each other (pos to neg) as a test to see if a led can burn. After i measure a voltage around 2.4v with 4 of them i connect the led to see if it will lightenup.

Soon i will try to make these with stable housing and then we can measure more thouroughly.

For the joule thief i ordered these sets, pict 1.

Im really wondering how this commercial lamp can lightenup such leds?? The housing is small, so cathodes also not big. Users just put saltwater in.

[George Harmony]

Looking good at the pict of the commercial saltwater lamp with usb charger i think i know now how they do it. Saltwater battery charges the build in lion battery. If im right, ofcourse one is able to charge a hp and even my usb lamp can then burn.

So they do not directly connect to the saltwater battery.

[Muhendis]

You got to be kidding about the lamp George. Please don't tell me people are putting salt water into a Lithium Ion Battery.

[George Harmony]

You got to be kidding about the lamp George. Please don't tell me people are putting salt water into a Lithium Ion Battery.

Ofcourse not. The buildin saltwater battery CHARGE the lithium battery constantly. Thats why i think. Dont know for sure.

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

Added:

Its a fact that (salt)water batteries can charge a handphone. For stable output perhaps they use a normal battery but they charge it with a water battery. They market it as saltwater lamp. If its true, very clever marketing. Leds connected to a lithium battery but charged with another saltwater battery.

Edited June 14, 2016 by George Harmony

[IMHO]

1.5v doesn't mean much without understanding some Ah readings.

Something like this might produce 50mAh I guess, which is 0.075 Wh. An 18650 li-ion cell is about half the size, and can produce over 10Wh. So you're going to need an awful lot of magnesium, and an awful lot of space to make something useful out of this design.

[Muhendis]

1.5v doesn't mean much without understanding some Ah readings.

Something like this might produce 50mAh I guess, which is 0.075 Wh. An 18650 li-ion cell is about half the size, and can produce over 10Wh. So you're going to need an awful lot of magnesium, and an awful lot of space to make something useful out of this design.

There's just too much guess work going on here. George hurry up and give us some figures so we can enjoy your success.