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Living offgrid with small solar system(s)


George Harmony

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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.

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@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

post-177483-0-61140700-1467882774_thumb.

Edited by George Harmony
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@crossy wrote b4:

Your CL0117 based joule-thief is going to be hard to beat.

For some leds only for sure. For 5v 7watt bulbs i think i have to find other ways like that stepup module or make some adjustments to this joule thief.

I have also a 5v 3watt led(s) and with this weak battery it burns but very weak unlike using the stepup module.

Only 4-5 leds like the pict the joule thief is perfect for using it with 1.2v battery. I shall make a sleeping/night lamp with this joule thief ??

post-177483-0-85109500-1467911392_thumb.

Edited by George Harmony
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@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.

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@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.

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@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.

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IMHO FLA's will last approximately 2 times longer than FLA's under the same conditions and with regular maintenance. Please let me know what make of FLA batteries last 10 times longer than VRLA's. I will go out and buy a load tomorrow. thumbsup.gif

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Is it possible to service/maintain a vrla battery? Mine is sealed or are there also unsealed vrla??

Unlike other sealed lead accid batteries its i think hard to open a sealed vrla and try to add (dist)water or restore otherwise.

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VRLA, (valve regulated lead acid) batteries and sealed maintenance free batteries are both sealed for life. they are capable of withstanding up to a point, the internal pressures created by gassing. Gassing being the breakdown of distilled water into hydrogen and oxygen which happens when you charge a battery. The gasses are recombined into the electrolyte which is why topping up is neither required nor possible without damaging the battery. It is because of the gas pressure that the VRLA and sealed for life batteries need a more carefully controlled charging regime. Unlike the FLA battery, they are not tolerant of overcharge and can quite easily be wrecked by such treatment. They do suffer from sulfation, as do all lead acid batteries, but to a lesser degree. The usefulness of the VRLA battery is that they can be used in an unventilated environment. From this it should be clear that there is no such thing as an unsealed VRLA battery. If you are brave/stupid then you can do what a few utube people have done and unseal the battery to clean the sulphate from the plates. The battery, which is quite likely already dead, then becomes an FLA without the screw caps. For all of that effort you may only get a few months additional life (if you're lucky) out of the battery. Battery manufacturers go to some lengths to ensure that the batteries are not contaminated during manufacture. Utube people don't.

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I have two battery banks. The set at the house are AGM sealed batteries. I bought these because they are in the house and I didn't want to worry about gases. The other set at the farm are regular deep cycle flooded lead acid. It's kind of a pain checking the acid levels but at half the price of the sealed batteries, they are by far the cheapest way to go. Both sets are over three years old with no signs of weakening. When/if I replace the sealed batteries, I will build a battery box for outside and buy regular deep cycle flooded batteries. Since I don't discharge my batteries more than 50 percent, I expect both sets to last for a long time.

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Someone gave me an old ups (sealed) lead accid battery, not a vrla.

Very easy to clip it open and the rubber on top of each cell is also easy to open, not glued.

I am wondering if i now have a fla???? Other assumption: If i buy a new one and clip it open do i have a fla???

I was not able to do this with a vrla.

Added:vrla is usually much more expensive

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Edited by George Harmony
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George. The battery in your picture is not sealed (as in sealed for life) and neither is it VRLA. It is simply some manufacturers idea of making an FLA less prone to spillage.

Gary A. I agree with your comment about the pain of electrolyte level checking. I reduced my dislike considerably by investing in a central watering system from a company in Germany called Aquapro. I have added some simple electronic control, a small submersible aquarium pump and a flow meter to make the filling semi automatic. I still have to go into the battery room to see if any top up action is required by looking at an indicator on each battery filler cap and if it is I simply push a button and let it run. My system automatically stops when the electrolyte reaches the required level. I also have to maintain the level of distilled water in the reservoir but it is far simpler than crawling around checking 96 filler caps individually. I have a total battery capacity of 16 x 200Ah. That's 3200 Ah for those that didn't pay attention at school. I limit the discharge to 20% so available capacity is 640 Ah.

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Wow @muhendis

What a great setup. Although you maintain it (semi)automaticly you only discharge 20% ?? How do you limit the discharge? Can you regulate this with your chargecontroller?

Edited by George Harmony
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Wow @muhendis

What a great setup. Although you maintain it (semi)automaticly you only discharge 20% ?? How do you limit the discharge? Can you regulate this with your chargecontroller?

The charge controller is fully programmable although the discharge level is monitored by voltage so the accuracy of 20% is not going to be so good. This is useful for when I change battery chemistry.

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That Aquapro setup is a neat system. The price of $79 plus shipping for a single battery seems pretty high. That makes checking the batteries manually more palatable.

I too use the voltage to monitor depth of discharge. On days with at least a little sun, the voltage seldom goes below 12.3 volts. Since my system is totally off the grid, I have an automatic charger that I can plug into the grid so that I don't go below 12.2 volts. Simple system but it works for me.

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That Aquapro setup is a neat system. The price of $79 plus shipping for a single battery seems pretty high. That makes checking the batteries manually more palatable.

I too use the voltage to monitor depth of discharge. On days with at least a little sun, the voltage seldom goes below 12.3 volts. Since my system is totally off the grid, I have an automatic charger that I can plug into the grid so that I don't go below 12.2 volts. Simple system but it works for me.

OUCH! That is so expensive. I can empathise with your reluctance to spend that sort of money. If you are talking Australian dollars that works out at just over 2,000 Baht per battery. Mine worked out to 850 Baht per battery direct from Rover & Rover GmbH. I did get a quote from a couple of companies, one in Australia and one in India but they were very expensive since they were the "local" franchise outlets. There isn't one in Thailand so I had no problem buying from the source in Germany at factory price.

These battery watering kits are mostly sold to companies with fleets of fork lift trucks for whom the costs are quickly recoverable unlike the home solar application. This is reflected in the local price.

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@muendis,

Is the lithium iron phosphate (LiFePO 4) battery MUCH more expensive than your above setup?? Considering this according to wikipedia:

◾100% DOD cycle life (number of cycles to 80% of original capacity) = 2,000-7,000

◾10% DOD cycle life (number of cycles to 80% of original capacity) > 10,000

Edited by George Harmony
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George. The economics of different technologies for storage batteries has been covered by many sources on the on the internet. Most of them have vested interests but all come to the conclusion that LiFePO4 batteries work out cheaper long term. The initial costs are extremely high (my personal opinion) but if the capital outlay is within your budget then they are a far better choice than lead acid. There are a few extra problems running LiFePO4's that need to be bourn in mind but the additional costs are comparable with maintenance costs for a lead acid. So on the whole, I would say that starting from scratch LiFePO4 is the best option for solar energy storage AT THE MOMENT. I would like to encourage you to look at two new technologies.

Sodium Ion and nano wire.

  1. The Sodium ion batteries are in production but very new. These are very similar to LiFePO4's but use much cheaper (due to availability) sodium. Apparently they are 20% cheaper than LiFePO4 and just as powerful but this is early days yet.
  2. The nano wire lithium ion technology is probably going to be far more expensive because it can allegedly manage 200,000 or more cycles.

I have no information yet about the charging characteristics for this nano wire battery but it is a chance discovery, based on known nano wire technology, which improves the strength of the nano wires to near invincibility (my interpretation). Until recently the technology has not made much progress because the nano wires which form the electrodes have not been able to withstand more than a few cycles before fracturing. A scientist in UC Irvine in America had a flash of inspiration (I expect George is familiar with those) and tried coating the nano wires with some sort of plexiglass gel and BINGO. A new battery was borne. It is estimated that it will be something like ten years before mass production.

For further reading you might like to look at this http://www.computerworld.com/article/3060005/mobile-wireless/scientists-can-now-make-lithium-ion-batteries-last-a-lifetime.html

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Gary A. I agree with your comment about the pain of electrolyte level checking. I reduced my dislike considerably by investing in a central watering system from a company in Germany called Aquapro. I have added some simple electronic control, a small submersible aquarium pump and a flow meter to make the filling semi automatic. I still have to go into the battery room to see if any top up action is required by looking at an indicator on each battery filler cap and if it is I simply push a button and let it run. My system automatically stops when the electrolyte reaches the required level. I also have to maintain the level of distilled water in the reservoir but it is far simpler than crawling around checking 96 filler caps individually.

Additional thoughts about my previous post. If the reservoir of distilled water is 1 Metre higher than the highest battery, the Aquapro system does not need a pump or electronic control system. Gravity, which surprisingly is cheaper than electronics, will do the work of pushing the distilled water into the batteries. The automatic cutoff is a function of the battery filler caps. So if the battery electrolyte level is lower than the nominal filler cap float level, the valve in the filler cap will open and allow water into the battery. When the battery is full then the valve closes. There is only one problem with this system and that is temperature. At the point when the batteries are fully charged the temperature of the battery is going to be at its maximum and the electrolyte will have expanded to it's full volume. Now is the best time to top up your batteries so a temperature controlled valve might be a good idea. With my system I simply do the top up at some time around mid day just after full charge has been achieved.

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And @naam, my shed nearly finished and roof will be covered totally later with solar panels. Just a village style humble shed but its more cheaper if i did finish it totally with bricks only. BUT, forbidden to build such in your moo-bahn??

Hi Guys. haven't been following the latest here for many days and smiled at the friendly banter happening. Means you are all well. smile.png

Also smiled at the tricks that cameras can do. e.g. just look at the leaning walls in George's new extensions. What kind of liquid lunches do you give them George. rolleyes.gif

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And @naam, my shed nearly finished and roof will be covered totally later with solar panels. Just a village style humble shed but its more cheaper if i did finish it totally with bricks only. BUT, forbidden to build such in your moo-bahn??

Hi Guys. haven't been following the latest here for many days and smiled at the friendly banter happening. Means you are all well. smile.png

Also smiled at the tricks that cameras can do. e.g. just look at the leaning walls in George's new extensions. What kind of liquid lunches do you give them George. rolleyes.gif

looking at the "more cheaper" workmanship i think George serves his labourers a mixture of battery acid adulterated with denaturated spirit. laugh.png

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Also smiled at the tricks that cameras can do. e.g. just look at the leaning walls in George's new extensions. What kind of liquid lunches do you give them George.

Sorry, dont know what you mean. Can you paste a part of the pict like @naam did before?

And @naam, yes you r right. Labor here is very cheap. About 11usd per day per worker.

Cheap labor or not, im satisfied ? and already had few storms and its still standing and the roofs not blown off ???

Roof of a carport of one of my nabor did fly about 30meters (3m high) and luckily it hit electric cables otherwise it flew into the big office behind our complex ???

On topic now. Been rather bussy with other things so still not finish the def setup of my waterbattery. Keep you informed.

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According to someone who reacted on this vid its fake. A diy saltwater lamp. Im not sure wether its fake or not.

It's not fake George. Salt water is a sodium solution which has plenty of ions for transporting electrons from one electrode to the other.

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having trouble loading the quote function ..

I saw the salt lantern vid.

If You google it..salt water lantern, it comes up to buy? I think..I dont have sun in my cloud forest , so it would really help at night around here.

Thanks again..

Aloha

ps. Wonder how @ naam is doing with ice trays..

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i dropped the ice tray idea but today i have a question for all the learned electrolytes posting in this thread:

on october 4, last year i acquired a battery powered gadget for which i paid 32,628 US-Dollars. i was told the battery will last approximately 8 years, cannot be recharged or replaced but the whole gadget needs replacement. by then the price will be most probably 40,000 US-Dollars unsure.png

whatr kind of electrical gadget am i talking about? it's size is 8x6x0.8cm (height / width / depth) and it looks like this:

Inliven.jpg?itok=QfNsSekQ

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