IMHO

@crossy, i got you. I sure will measure.

About panasonic batteries.

For the price of this i can buy here panasonic 12v 7Ah vrla ???

But ofcourse for quality you must pay

VRLA batteries have terrible cyclic life though - even at just 50% depth of discharge, you're only going to get 400-450 cycles out them at 25c, or about 200 cycles at 33c.

This is why we tend to keep maximum discharge to 20%. The economics just don't stand close scrutiny with lead acid batteries because if they are discharged to 50% or 60% then they will need replacing sooner. If they are discharged to 20% then the number of batteries needs to be increased to achieve the same capacity. Meanwhile and especially with solar charging, the capacity of lead acid batteries will be reduced due to sulfation so the additional cost of the desulfation cycle charger needs to be added.

Uh huh, but also don't confuse VRLA with good old regular flooded lead acid - the latter is capable of up to 10x the cyclic life of VRLA.

@crossy, i got you. I sure will measure.

About panasonic batteries.

For the price of this i can buy here panasonic 12v 7Ah vrla ???

But ofcourse for quality you must pay

VRLA batteries have terrible cyclic life though - even at just 50% depth of discharge, you're only going to get 400-450 cycles out them at 25c, or about 200 cycles at 33c.

With 4 of these rechargeable batteries i get about 4000mAh (1.2v)

If you want quality AA/AAA 1.2V batteries, there is only one brand to buy:

http://www.panasonic.com/global/consumer/battery/eneloop/lineup.html

In fact so good, Panasonic bought them from Sanyo

I have never yet purchased a single Ni-Mh or Li-ion cell from China that achieved anything near it's rated capacity and/or cycles.

IMHO I agree with your comment "Given the seemingly short lifespan of tech gadgets and people's hunger to upgrade them- often for little to no benefit - it probably won't be that much of an issue " I also had in mind larger products like car batteries, PV storage, electric automobiles and grid storage to say nothing of the millions of warehouse forklift trucks. All these applications regularly replace their batteries and keep the battery manufacturers and distributors busy. What would be the scenario if the batteries all came with a 200,000 cycle life expectancy?

Probably the same solution tech gadgets employ: planned obsolescence

Jokes aside, the increasing number of devices powered with the help of batteries probably goes a long way to offsetting lower frequency of replacement?

Not my industry, just guessing

You guys should take a look at what's happening in the world of batteries. Even Georges water cells get a mention.......http://www.pocket-lint.com/news/130380-future-batteries-coming-soon-charge-in-seconds-last-months-and-power-over-the-air

Oh great, so now the energy companies are going to destroy the world's forests by making them into grid storage?

Bioo offers two to three charges per day at 3.5V and 0.5A via a USB port that's cleverly disguised as a rock. The pot uses organic materials that react with the water and organic matter from the plant's photosynthesising. This creates a reaction that generates enough power to charge gadgets.

This is just the start, imagine entire forests harnessed in this way. Not only could cities be powered with 100 per cent green energy but there could be yet another reason to protect plants and trees.

Hang on a minute. I'm just going to pop into the jungle to recharge my tablet.

Of greater concern is the trend towards batteries that outlast the gadget which they are powering. Nothing wrong with that except that the commercial aspect of this is quite likely going to be scary because although the batteries will be cheap enough to manufacture, the markup on them will need to be sufficient to keep the battery company in business. There will be little if any replacement of worn out batteries.

Given the seemingly short lifespan of tech gadgets and people's hunger to upgrade them- often for little to no benefit - it probably won't be that much of an issue

You guys should take a look at what's happening in the world of batteries. Even Georges water cells get a mention.......http://www.pocket-lint.com/news/130380-future-batteries-coming-soon-charge-in-seconds-last-months-and-power-over-the-air

Oh great, so now the energy companies are going to destroy the world's forests by making them into grid storage?

Bioo offers two to three charges per day at 3.5V and 0.5A via a USB port that's cleverly disguised as a rock. The pot uses organic materials that react with the water and organic matter from the plant's photosynthesising. This creates a reaction that generates enough power to charge gadgets.

This is just the start, imagine entire forests harnessed in this way. Not only could cities be powered with 100 per cent green energy but there could be yet another reason to protect plants and trees.

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.

@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:

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

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.

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

Volts? Amps?

Is that one cell driving a white LED directly without a joule-thief?

Electrodes? Electrolyte?

Its driving that tiny dc motor you see on the pict. Ive ordered the components for making joule thief. Hope to receive it today. Just doing some experiments myself for learning. I later ofcourse try to make some lamps myself with serial and/or paralell connected saltwater cells.

What i just did is half burned pencil touching a copper wire and as cathode alumium foil. Works also. So you dont have to take out all the graphite from the pencil

Will keep you updated.

That tiny little motor could probably be powered by a lemon or potato battery - can't get more eco than than that

This hotplate with watercooler consists of some peltiers and can generate up to 100watts. The hotter the better. Im wondering if i can put such a device in a diy solar oven??

Two things on this idea:

1. If you have solar energy, PV @ ~16-18% efficiency is the smartest way to create electricity from it.

2. Peltiers are a 'heat pump', so when you place them on your solar oven, they're going to cool it down.

Peak output, possibly https://en.wikipedia.org/wiki/Supercapacitor

If you mean running multiple inverters in parallel, yes, provided the inverters are designed to work that way.

It's also possible to use a small pure-sine inverter to trick a grid-tie inverter into starting up and supplying power (Google AC-coupled solar), handy to get things going if the grid is off and the sun is shining.

I'm guessing all a grid-tie inverter needs to see is an AC waveform within it's own operating frequency range? I can't imagine anti-islanding works by looking at voltage, otherwise you'd never be able to have parallel grid-tie inverters.

Let me put it this way:

If i dont sprinkle it will be hotter inside.....right or not??

It should cool down your attic, yes. How much effect it has on the rooms below solely depends on how good your insulation is.

I can say that in my houses, it wouldn't do much - we get maybe only 2-3c of heat gain through the ceilings each day, and that's all happened by mid-afternoon anyway. We use ventilated soffits all the way around our house though, so as soon as there's any breeze, the attic is getting cooled naturally, and completely free.

Again stubborn George. In my case water is no problem at all. Also groundwater. Sprinkling a roof for couple of hours thus no problem with my tiny pumps hehehe....see the thai vid posted by me for @gary before, page 28.

If its working for a chicken shed why not for my tiny house?? Give me a good reason. Ofcourse it wont work like an aircon but if inside it will be cooler, why not give it a try.

Attached pict screenprint sprinkler system thai vid page 28.

If using ground water, just bear in mind that your roof might not look very pretty for long

^but what about hamsters in wheels?

I reckon 25 hamsters on separate wheels should generate enough power to run the pump that will feed the sprinklers to cool the roof.

imagine what an army of hamster could do.

Take over the world.same as we do every night PInky.

I still think a solar heat powered stirling engine make more sense

One poster said: "Dehumidification alone makes a room feel cooler".

I already run (exhaust) fans and other fans. Incoming air seems also not dry. So im trying to find a way to dehumidify my living room.

Read about salt and other products who can absorb. @jingjoe gave outdoor protection tips.

If i must run an electric dehumidifier i can better run that 260w aircon (50%). So what are the alternatives..???

I did say that, but also said the best way to do it is still a proper AC

If you cool water to say, 20c and put in through one of these in a 35c room, it's not going to have anywhere near the efficacy of the heater style.

Thats im wondering in the first place. How cold can be the outcoming water after circulating for for example 1 hour as per above setup. If its constant under the 10c it can perhaps be interesting.

I just try to find a way too cool down 3-5c more. On a very hot day my room temp is 28-30. With fans its "feels" cool although the room temp is/remains high.

Ofcourse an aircon is the most efficient way to cool a room. If there's no other way i must plan for that 260watt lg hercules aircon later or a dc aircon.

There's another thing that an AC will do that your proposed system will not - dehumidify the air. Dehumidification alone makes a room feel cooler.

Again, the correct solution is still an airconditioner.

Can i conclude:

Circulating hot water through a radiator like this will certainly warm up a space/room but with cool/cold water will not cool the room or lower the temp of the room.

I maybe ask and react silly and stubborn but i wont even test it if 100% of the reactions find it not a good idea.

There's no reason it wouldn't cool the room - so long as you can achieve the same delta's as what a heater of this style does. e.g. these heaters work great in a ambient temp of 0c (or less) and a heater temp of 35c. If you cool water to say, 20c and put in through one of these in a 35c room, it's not going to have anywhere near the efficacy of the heater style.

I still contend that it's a very inefficient way to cool though. Nothing beats the efficiency of an actual refrigerant, a compressor and separate indoor/outdoor heat exchangers with fans. i.e. a split system AC.

The Right Honourable Sir Overunity Hopeful talks about a 40L mini-freezer which has a cooling capacity of approximately 500-700 btu/h

Didn't catch that part, was assuming a normal sized one

500 BTU is about the amount of heat a human emits. Forget about it cooling 1 sqm if you're in it

Cause when in theory after circulating the water the water is really cold, for example cool or cold 5-6c, i then can circulate continious cool water to a radiator instead of having a cold shower.

My first question: Will the outcoming water be much cooler. By heating with the sun it will be much hotter and @naam and others warm up their pool with such a system.

How is it with copper sipral in een freezer. As muhendis said freezer must be full. Ok, i make ice first in a plastic bag 1 inch thick and as wide as the freezer and put it on the bottom. Then put the copper spiral above. Above the spiral again ice. And on top food and other stuffs u usually put in a freezer. There are as said above only two holes, insulated, and outside pipe connected ofcourse to the spiral copper inside.

Another thing is: If the water coming in the copper pipe is already cool 5-6c, will it remain steady cool when the outside ambient temp is e.g. 27-28c.

Just an idea.

You still need to bear in mind that this freezer has a finite cooling capacity. Probably around 2000 BTU/hr.

You also need to bear in mind that it's incredibly lossy - no matter how well it's insulated - that's why it doesn't stay cold without continual energy consumption, even when all the contents have reached target temperature.

There's just no efficient way to store 'cold' - it's more efficient to just make it on the fly as you need it.

Actually, an SEER (Seasonal Energy Efficiency Ratio) of 10 is pretty low guys - SEER ratings appear to be easily manipulated to achieve very high numbers too.

IMHO, EER is the rating that matters if you want to understand actual energy efficiency. EER is pure BTU / Watts, with no funky adjustments or algorithms for seasonal energy usage.

As an example, on of my newer big Daikins can do 29,000 BTU with a max. power consumption of 2390 Watts. That's an EER of 12.13. The SEER rating of that same AC is 18.63.

The smallest in that range does 8,700 BTU with 490 watts = an EER of 17.76. The SEER rating on that one is 23.76.

Of course it is, but we're in the market for crazy ideas here

OK, here's mine then:

Cool your house using the Troposphere!

It's only ~2KM away from where we are, and down to ~17c at that point, and surely thermal buoyancy will help lower the total energy cost of the complete round-trip, no?

Not enough cooling? just send your heat exchanger closer to the Tropopause (~20KM) where the air is now down to around -50c!

Here's the basic concept behind this idea:

1. Balloon - to provide the system with enough lift to get it all up to the Troposphere and keep it all up there. Of course, an anchor will be needed, but we can use our piping for that (more on that later)

2. Small PV panel - atop of the balloon to provide power for a small fan to promote airflow through the heat exchanger located in the Troposphere. The low temps and higher radiation levels should substantially improve upon the STC reference harvest.

3. Heat exchanger with fan - to improve overall system efficiency up in the Troposphere.

4. Insulated supply and return pipes. We'll use water as the medium because it's cheap, easily replenished, doesn't require high pressure, and crucially, can take full advantage of the thermosiphon principle. We'll use anti-freeze additives as required, of course.

5. Small PV panel at ground level, powering:

6. A heat exchanger and fan in the target room to be cooled.

End result: a 100% free energy cooling system with variable cooling capacity (altitude).

7. Red flashing hazard warning lights for aircraft appropriately spaced on the downfeed.

8. Local air traffic control regulatory approval for parking your balloon in their sky.

9. Balloon to be radar visible.

10. Planning permission for a structure to tether the balloon.

11. All fixtures and fittings to be in conformance with aeronautical regulations and to be failsafe.

Go for it IMHO.

All doable

Of course it is, but we're in the market for crazy ideas here

OK, here's mine then:

Cool your house using the Troposphere!

It's only ~2KM away from where we are, and down to ~17c at that point, and surely thermal buoyancy will help lower the total energy cost of the complete round-trip, no?

Not enough cooling? just send your heat exchanger closer to the Tropopause (~20KM) where the air is now down to around -50c!

Here's the basic concept behind this idea:

1. Balloon - to provide the system with enough lift to get it all up to the Troposphere and keep it all up there. Of course, an anchor will be needed, but we can use our piping for that (more on that later)

2. Small PV panel - atop of the balloon to provide power for a small fan to promote airflow through the heat exchanger located in the Troposphere. The low temps and higher radiation levels should substantially improve upon the STC reference harvest.

3. Heat exchanger with fan - to improve overall system efficiency up in the Troposphere.

4. Insulated supply and return pipes. We'll use water as the medium because it's cheap, easily replenished, doesn't require high pressure, and crucially, can take full advantage of the thermosiphon principle. We'll use anti-freeze additives as required, of course.

5. Small PV panel at ground level, powering:

6. A heat exchanger and fan in the target room to be cooled.

End result: a 100% free energy cooling system with variable cooling capacity (altitude).