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Author Topic: Blasphemy..... Solar power.  (Read 148413 times)

BruceM

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Re: Blasphemy..... Solar power.
« Reply #165 on: October 27, 2017, 06:29:50 PM »
Thanks Mike. Your report is most interesting.  The water use is a real eye opener.  Adding 5-6 gallons of distilled water to all the cells every 2 weeks is a show stopper for me.  Is this due to overcharging and thus avoidable with a NiFE smart controller? What does bubble production vs voltage and charge current over time look like?  If they only start really bubbling when fully charged-  charge detection seems the answer.   

Or perhaps there is an automatic waterer available?




LowGear

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Re: Blasphemy..... Solar power.
« Reply #166 on: October 27, 2017, 06:46:00 PM »
Quote
Adding 5-6 gallons of distilled water to all the cells every 2 weeks is a show stopper for me.
  Me too.
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Tom

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Re: Blasphemy..... Solar power.
« Reply #167 on: October 27, 2017, 07:37:47 PM »
My FLA bats, now 10 years old, regularly use 5-6 gal per month. This is a 48v 1055 ah bank of 4 Hawker PV1 batteries. So Mikes water usage is not to far out of line. I made a setup with a 5 gal cooler bottle and 5/16 vinyl hose to water the batts that works very well.
Tom
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BruceM

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Re: Blasphemy..... Solar power.
« Reply #168 on: October 27, 2017, 08:25:49 PM »
I'm feeling better and better about my own small scale DIY 120V system.  I check water in a few batteries annually, add about 1 gallon every other year.  I started with every couple months and just kept extending the period. My neighbor has an improved version of my individual battery regulators and we've gradually increased his temperature compensated float voltage slightly per battery over the last year to reduce variation in specific density between cells.  His (10) battery shunt regulators allow trim pot adjustment of temp compensated battery float, bulk, and equalization voltage levels.  He has even less need for mini-equalization charging now and is down to once a month, and still dropping, no noticeable water use.  He's also using 10 group 29 marine batteries from Johnson Controls (Walmart), at $89 each.  I will be updating my hardware to the new version this winter, knock on wood. 

For wet lead acid some of that water adding is the fault of bad charge/charge controller design,  because of the lack of individual cell (or smaller groups of cells) management.  I designed for AGM, for which you have to be much more careful, as water can't be added(!), so overcharging is not operationally acceptable.

The larger capacity deep cycle wet lead batteries may also NEED high charge rates and some bubbling according to some of the literature I've read on forklift type batteries.





BruceM

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Re: Blasphemy..... Solar power.
« Reply #169 on: October 27, 2017, 10:51:39 PM »
I did find lots of nice battery watering systems that could be fully automated.  Fillwatch seems like a nice one, though spendy.  Trojan makes them also.  Freezing of residual water in the tubes above the battery is something that they did not seem to address at all; and would be problematic for me. I don't heat my outdoor vented battery cabinet.

Back to holding my breath for that big battery breakthrough.  If I was a serious survivalist,  NiFe would be more interesting due to extremely long life.

BruceM

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Re: Blasphemy..... Solar power.
« Reply #170 on: October 28, 2017, 12:44:24 AM »
Not water vapor; it's hydrogen and oxygen from electrolysis.  The battery boxes must be vented to minimize explosion risk.


mikenash

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Re: Blasphemy..... Solar power.
« Reply #171 on: October 28, 2017, 01:46:44 AM »
Hi Bruce

I'm interested in your thinking on this

My last solar setup I basically had panels, fairly cheap deep-cycle batteries, a controller, an inverter and a voltmeter as a "fuel gauge"

I need to build another in a few years when I "retire", and my thinking was that panels, AGMs and one of the smart inverter/controllers that will accept DC and AC inputs, would be a good balance between not too high-tech and not too basic.  It would allow me to use the Lister with the ST head and the DC alternators to contribute 230VAC when I had a "big load" day, or 24VDC to charge batteries when there had been a few low-sunlight days.

Although the beautiful, industrial, heavy-duty batteries such as the Telecon 2V units appeal, I thought the low-maintenance AGMs might be an OK compromise . . . .

Has it been your experience that the extra work of hygrometers, electrolyte, top-ups etc etc is justified?

I'd be interested in your thoughts

Thanks, Mike

Samo

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Re: Blasphemy..... Solar power.
« Reply #172 on: October 28, 2017, 03:32:51 AM »
Quote
NiFe info
my install:
https://www.facebook.com/media/set/?set=a.209715335768594.51674.120212794718849&type=1&l=9747e4dde6

> Maintenance
  lots, every 2 weeks, I add 5 or 6 gallons distilled, 20 gall was too much to do at a time, so I'd shifted the cycles around so I'm only doing a quarter of the bank at any 1 time.

> Charge/Use cycles
 ?? I charge and use them

> Efficiency
  about 60%, that's why they use so much water.

> DOD - how far down do you run them?
 the bank is 40,800 watt hours, (51v [42 cells] * 800Ah). My running voltage at sunrise is about 52v in summer, and 49v winter (longer nights) I figure my nightime consumption runs about 5Kwh. I sized to properly allow for their high internal resistance, and to supply starting surge for deep well pump, so I generally have low voltage droop.  I charge below recommended voltage, because that would fry my inverter.

Thanks for that detail Mike. Like others I was surprised at the water use. I've read they use some but that puts it into perspective. I read about them a bit and it's hard sorting out the truth from the various claims.

cheers,
Samo
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BruceM

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Re: Blasphemy..... Solar power.
« Reply #173 on: October 28, 2017, 04:16:31 AM »
Mikenash-
I do use a single 12V AGM battery for my home/shop 12V power; it runs my circ pumps, and is used for control for computers, power, Controllers and such.  For that it makes sense because it allowed me to eliminate a vented battery box in the shop an the winter thermal cost of doing one as well.  The higher charge efficiency and relatively long life for this application (8 years+) make it worthwhile.  I much prefer AGM batteries; I just don't want to pay the premium extra $/month replacement cost.  If they were 1.5 times the cost wet marine batteries, I'd already be using them.

I'd wait to make a decision until you are closer to the time...see what makes sen$e then. For anyone with any family members with neurological, autoimmune or endocrine problems at all, I would suggest reading up about what is being called "dirty power" (the terminology and much of what is written makes me shudder at the technical inaccuracies) and realize that a typical inverter system today has absolutely horrible high frequency emissions radiating from all the connected wiring. This is easily confirmed via AM radio with a non-noise suppression tuner like the old Radio Shack 12-467.

A better plan, health and cost wise, is to get the inverter, panels, and batteries out of the home in an outbuilding, and filter the heck out of the AC power going to the home, which should be in metal conduit after the filter. This saves a great deal of expensive additional expensive shielding of the inverter, filtering the DC from the PV system, etc. and if planned into a multi-use outbuilding, adds no cost.  The trick is to avoid filters that are a high reactive load due to capacitance, either line to line or line to ground, as reactive loads are the same as real loads to most inverter designs; they eat your battery power 24/7. If nothing else, at least use one of the commercial two stage common mode filters by Schaefer or others. (Very low capacitance.)  Who knows, by then, some of the companies my offer a low EMI choice as an option.

Designing in low emissions by the original designer is the way to get the best possible performance at the lowest cost. Today, the public and marketing dweebs only know cost and capacity or some other fancy features; EMI isn't part of public awareness.  When I talked to Magnum power about filtering their product, their engineers knew just where the emissions where in frequency, and how to best tackle it.  Alas, for cost/marketing competitiveness reasons they can't design it in to the design, or even as an add on.  Admitting that these products might be a health risk is something none of them want to go anywhere near.

Generally my thoughts are that parallel batteries are a big mistake, that individual battery regulators ala AGM car battery designs (see manzanitamicro.com - one of the early AGM electric car supporters) are the best way to allow longer serial strings without problems or endless watering issues. I much prefer higher voltages, and find 120VDC very, very handy.  In commercial gear I would avoid less than 48V unless it was for a bargain cabin of very, very low power use.  The lower voltage systems lose a lot of power in voltage drop to the inverter inputs, and in PV wiring, etc.  This is why virtually all new systems have gone to high voltage PV arrays (many greater than 120VDC).  They are still shackled by 48V on the battery side because of the industry influenced decision to allow non-electricians (certified PV installers) to wire up lower voltages.  A technical blunder which will be overtaken, eventually. 

But then some amazing blunders made in around 1920, like the non-transformer isolated  grounding practice of the Wye
power distribution system have continued for nearly 100 years.  Humans tend to cling to our well established blunders.

« Last Edit: October 28, 2017, 04:24:41 AM by BruceM »

mike90045

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Re: Blasphemy..... Solar power.
« Reply #174 on: October 28, 2017, 05:56:53 AM »
bear with my crippled left hand hunt & peck, just got a new shoulder on right side last week
https://www.ucsfhealth.org/treatments/shoulder_replacement/

 water usage in 5-6 gal, every 2 weeks, in about 10 cells.  If i'd waited till they all needed water, it'd take close to 20 gal at a time.   E to F is about half a gallon in a cell

mikenash

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Re: Blasphemy..... Solar power.
« Reply #175 on: October 28, 2017, 06:55:52 AM »
Fascinating thoughts Bruce.  Thanks for taking the time to put all that down "on paper"

I hadn't considered emissions/health - something to think about

Cheers

dieselspanner

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Re: Blasphemy..... Solar power.
« Reply #176 on: October 28, 2017, 07:16:29 AM »
Hi Mike
Just out of interest, where do you get the distilled water from, and a what cost?

Cheers Stef
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starfire

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Re: Blasphemy..... Solar power.
« Reply #177 on: October 28, 2017, 08:24:20 AM »
One of my many income streams is the repair of radio and electronic equipment, and any interferrence from my mains supply would render my workshop useless.. To get an "RF quiet" inverter is difficult, as the EMI filtering is the very first thing left out as a design cost cutting measure. It cannot be added retrospectively.
Most inverters use the "high frequency" approach, where the low voltage DC is chopped at a high frequency to AC, rectified to high voltage DC, then chopped again at 50/60 cycles into  some pretence of an AC  sine wave.
These are cheaper to manufacture and have a fairly small footprint, the high frequencies mean smaller transformers.
The better type are called "low frequency "inverters, where the initial voltage step up is done at the same frequency as the mains output. These are very much quieter, and use less components as everything is done in one conversion stage, but these require large transformers, lots of copper, lots of iron, therefore more expensive..... but very reliable,  the low frequencies minimise commutating losses , less stress in the semiconductors. These are the RFI friendly ones.
Chopping DC using square waves  to do a voltage conversion  creates harmonics.
50/60 Hz harmonics are unlikely to cause issues above the 4th/5th, or a few hundred Hz at low to medium power levels.
High Frequency chopper harmonics extend well into the HF bands, and the house wiring acts as a very efficient radiator/aerial/antenna, transmitting RFI and hash.for many hundreds of meters. 
i have had a good run  with  the Australian SELECTRONIC brand, my two are  low frequency types . are over 20 years old and have  never failed despite running 24/7.  This company still appears to be  in business, but unsure of what design the later offerings use, but there is bound to be other manufacturers using this approach.
To increase reliability with the generic Chinese cheapies, my advice is to divide the building into many self contained circuits, and use a multitude of smaller inverters to run each section independently. Small inverters are cheaper to buy, they tend to die with dignity, generally they just stop working , rather than dramatically catching fire as the bigger ones do, and they will never all fail at once.
But, your gunna be stuck with the RFI problem using these..
Buying expensive inverter equipment is rather like buying expensive power tools, its a great thing at the time, but years down the track, they have become a discontinued model, and either parts are unavailable, Hitachi are very good at this, or the manufacturer has gone out of business.
The smaller Chinese inverters, 300 watts or so will run lights and small appliances well, and will generally last 2/3 years. They hate inductive loads, this is what kills them, voltage spikes caused by poor regulation. The lF types with their big transformers soak up these spikes by virtue of the high inductance between the load and the semiconductors.
Of course, large professional stuff costing megabucks and needing its own building and full time maintenance team is another story entirely.
Im just a little fish.
Our engines may last 100 years, but sadly nothing else we can afford / need will.

starfire

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Re: Blasphemy..... Solar power.
« Reply #178 on: October 28, 2017, 12:03:29 PM »
And another idea. With the vast amounts of Oxygen and Hydrogen  generated by these NiFe batteries,
I have it on good authority that this is whats uniquely known as Browns gas, after he invented it just a few years ago, and can be burned in engines and requiring no other fuel. It makes sense then to run gas lines from the top of each battery into the engine air intake and utilise it as fuel.  The faster the charge rate, the more gas will be needed, and the more gas will be produced, an automatic process.... very neat I thought. The condensed steam from the exhaust will be pure distilled water, and could be returned to the batteries after cooling to  create a closed loop cycle, needing no user input.
Why has no-one thought of doing this?
« Last Edit: October 28, 2017, 12:15:05 PM by starfire »

AdeV

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Re: Blasphemy..... Solar power.
« Reply #179 on: October 28, 2017, 12:32:51 PM »
I await Glort's rant on perpetual motion machines with some interest  :laugh:
Cheers!
Ade.
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