Lead Acid Storage Batteries

Extra electrolyte will not help. In addition any common tank for the electr0lyte will short out the cells, it is a conductor.

Keeping them fully charged makes them live longer, where you can

They can tolerate the cold, but are more lossy at low temps and capacity is redued, so keep them in the war insulated part. Use battery caps with catalytic recombiners in them in case you over charge, no hydrogen will be vented.

The electrolyte is not a liquid fuel in the sense that gas-oil is a fuel. It is simply there to provide a medium within which the electrochemical reactions at the plates of the batteries can take place. So, no, the capacity of the battery will not be increased by supplying an excess of electrolyte. The capacity of a battery bank is related to the surface area of the electrodes, which generally means for more storage, use more batteries.

Consider using deep-cycle marine-type 'domestic' batteries for this sort of application rather than 'engine start' batteries. The latter are designed to be able give a lot of current for a short time. The former are designed to give a steady current for a long time and will recover better and more frequently from the effects of deep discharge. They are therefore more suited to off-grid energy storage applications.

Other comments are correct.

In addition: store and use the power at the highest practical voltage, and, use heavy duty cabling, so that you do not waste too much power in the wiring.

I agree with most comments already made except that SLAs (sealed Lead Acid) are often more expensive....and not needed, provided you do not overcharge. You should never overcharge anyway.....even SLAs.....

Having access to the electrolyte, will allow you later to know the "health" of each cell better as you become accustomed to using them....

The best bet is always slightly more battery capacity than you calculate you need as over some years, batteries can lose capacity and you might get a few days low on sun too....

Make sure that your charge controller has an adjustable point at which it stops charging and set this no higher than 14.2 (assuming a nominal 12v Battery) or even slightly less volts, which is before gassing even starts. Temperature plays a significant role too, read about this in the URL I have posted below.

Make sure that you do not deep discharge your batteries, even though "Leisure" batteries are made to handle this, it is not good practise.

Make sure that you have some method of removing a battery from use when its capacity is used up...never deep discharge (as I just mentioned before!)

I would recommend only Leisure batteries, they can handle more abuse than others....not so good for starting car engines though as max instantaneous current is limited, unless you have one with aproximately twice the capacity of the original car battery.....

It is usually better to have at least two systems, you can fix one while the other is still be used for example. When will a system fail? In the middle of the night of course!!

A good start is to read from this web site:-

http://www.batteryuniversity.com/partone-13.htm

Make sure that you always have fresh water and a neutraliser handy for acid spills. Your eyes will thank you.

Always use full safety equipment for your face and body. Old clothes are a must as unnoticed acid spills burn nice holes at the next wash (unless the clothes are washed immediately...)

Good ventilation to get rid of any charging gas as it is highly explosive.

Keep the batteries relatively warm in winter and cool in the summer....good insulation is a must. Too hot and too cold are bad for such batteries.

Never smoke or bring naked flames or open and close circuits (with possible sparks) near to the batteries. The batteries should be in one area and your switchgear and controllers in another. Either side of a dividing wall is best. Ventilate both areas before working.

Fuse everything correctly with sealed fuses, next to each battery, as a last resort fuse. Normal fusing with the controllers.

Read all the manuals you can obtain, talk to people who have done this learn, learn learn. BEFORE YOU INVEST MONEY.

Maybe start with a small system and learn there before putting out big money, maybe secondhand stuff from someone upgrading....start cheap unless you are a multimillionaire!!

Replace all your lighting with Fluorescent, or CFLs or LEDs, so as to reduce current usage, incandescent and Halogen are current eaters.....you (I do it already)should be doing this anyway.....

Switch off lights when not needed.

Reducing your usage of electricity today can make a Battery Solar system less effective financially as the costs are high with Batteries in the beginning....it could takes years to get a payback.....sit down and do the Math!!

All good stuff. Would add a weird one that I have seen proved over the years; don't sit the batteries on a concrete floor. For some reason it seems to allow them to discharge more quickly.

Thats been mentioned in other Blogs too, strange one....maybe they don't like having a cold bottom, my Missus hates it!!!

She gets pretty "discharged" over it too......I find it re"volt"ing......

Trouble at 'ohm' can be most distressing.

Oldie but still goodie!!

You are attempting to built a flow battery you must have visited this site but i think worth noting www.en.wikipedia.org/wiki/Redox_battery , well charged battery minimises sulphation , you will have to increase plate size with volumetric increase in electrolyte for coverage of electrolyte for efficient charging but that is not practical ,it will increase the weight ,and battery resistance will also increase , also increasing electrolyte won`t help , inducing charges nearby plates to far away is different thing , it is highly inefficient , you will probably keep on charging and start chemical reaction that was not intended to

You should see a small gain in capacity by circulating extra electroliye through the cell.

As Aurizon pointed out: each cell must be separated! i.e. a separate resevoir+pump/cell.

This will also take each plate set further down the discharge curve, reducing life time.

Probably not worth the effort.

Thanks for all the feedback on this question. I have decided to purchase a set of surplus nuclear submarine batteries instead of conventional deep cycle batteries. They are more expensive to be sure, but they have immense storage capacity, and very little maintenance is required. I'll never have to worry about overcharging with those babies, and I should be able to rely on them well after I've retired. The disadvantage that bothers me most is that I'll have to use a 12 volt setup because of cost, but I can live with a 12 volt system that has 92,000+ watt hours of storage capacity. The six cells will take up less than 12 square feet of floor space, and weigh over 6400 lbs. Is it possible to generate @ 48 volts and step down to 12 volts for charging economically?

Fantastic....

I guess you are going to buy 6 cells and link for 12 volts.

With such big cells, as you put it yourself, you will never overcharge!!

It sounds terrible to do, but you could put your 48 volts directly on the battery!! The battery will drop the voltage down to its voltage and maximum current will be drawn, no losses from other equipment.....that is assuming that your solar source will a) not be damaged by such usage b) that the solar source is not so huge on current that it drags the cells up to 48volts!!!

My biggest worry is the efficiency of Lead acid batteries is only about 75%-80% or so (from memory) and if you don`t have enough current/voltage, it will just sit there doing nothing, the losses will be greater than the input!!!

Checkout the following website:-

http://xtronics.com/reference/batterap.htm

You will need quite a large array of solar collectors to get these babies even to start charging!!!

These batteries are "repairable" and fully maintainable, some Telephone exchanges have batteries in the UK that are 60 years old or more....they will live longer than you!!

Yeah, you could just let the batteries drag your solar module voltage down, but is you look at the current versus voltage graph for a PV cell you'll see that there is a point at which the product of V and A maxes out, and either side of that point you're not getting so much power. Its the MPP. It looks like the knee voltage on a diode curve. And frankly, if you ran a 48V panel/array at 12V I guarantee you you are a long way from the Maximum Power Point. Its just a waste of solar capacity.

There is at least one good answer for this application: The Plasmatronics PL series of solar regulators can charge a 12v pack from a 48V input, and is fully programmable in the bargain. It will also start your generator automatically, record everything about your system. You set the float, it'll do different battery chemistry types.

As you may guess, they aren't very cheap, Australians earn 20 bucks an hour, not 2 bucks a day like the Chinese, but they are very good kit.

Ebay has the PL20 (20A) for about 400 AUD i think, you should be able to get PL40 and PL60 as well for a little more. No, I dont work for them, but I would always feel happy to fit one.

All the best,

Brett

Nuke sub cells??? You do realize, these will shipped minus the electrolyte....well, I guess they would be. These suckers take a lot of that stuff AND as I recall, they aren't lead-acid batteries. You are talking a bunch of gallons....a couple of dollars for sure. Wowza!!

Each cell needs 22 gallons of regular auto electrolyte, quite a bit too be sure. But I should only ned to add water every couple years. I was planning on charging them initially with a 7000 watt Honda generator, over the course of many days I'm sure. Then I will be attempting to keep them charged with a 3kw turbine, and a 480 watt PV array. The nice thing is that I can add generating capacity whenever needed without having to modify the battery bank at all. A friend gave me a true sine wave 3000 watt inverter, 12 volt thankfully. I should be set. I'd rather worry about adding charging capacity than adding storage. I'm buying the batteries now, about a year in advance, but they should only go up in value, so I'm kind of hedging against inflation.

Man, I have to ask. Where do you buy old storage batteries from nuke subs? I know the USN is recycling nukes at PNSY (has been for years), but how did you come across something like this. BTW, I guess Parche's batteries will be available soon.

What are Parche's batteries?

I am no expert, but why would a Nuke have batteries????

Usually only conventional diesel subs need batteries when underwater.....!Or is Nuclear power so unreliable?

Thank you Andy!!!! I was about to ask the same question!! Nuke subs have so much power, they have no need for batteries. I have a hunch that someone is yanking this guys chain a whole lot. The last diesel/electric (hence the need for batteries) got decommisioned many years ago... at least in the US navy... and I am willing to bet the same for the Brits.

The Russians (***_possibly***) still have a few diesel subs afloat (I guess).

Thus the lead plates from these batteries are probably heavilly oxidized... or sulphated (assuming they were taken from working subs in the 1960's).

I can guess that he might be getting Russian batteries new, but I am willing to bet that he is being led down the garden path by someone who has no more knowlege of what he is doing than a pissant and his customers have the same or worse.

Bill

Diesel/Electric subs are still in use and being built for many Navies around the world surprisingly enough, Germany is a leading builder of such items.....

But of course, there are nowhere near so many as say 40 years ago.....

The good point for the batteries is that they are "repairable" as a word to use and can be kept fit for many, many years.....they can be disassembled and cleaned out etc etc

Nice to have the contact with you!

Nukes still have a need for battery power. If the reactor scrams while underway, a lot of energy is required for a restart; to heat the pressurizer if I remember my reading correctly. The emergency diesel does not have the ampacity for that. Also, the diesel can't be run if they are submerged at depth and need power to drive to the surface using the emergency electric drive. They would be royally screwed if it were not for a high ampere storage battery.

WOW! That has been a secret for a long time........! Until today anyway......

The batteries are manufactured by EXIDE corporation, they are mil-spec, 2.2 volt batteries. They are being phased out, replaced by more efficient batteries from Enersys. I decided to purchase them because they are readily available, and have a proven track record of bullet proof reliability. Here is just one source of the batteries. http://www.relocationspecialists.org/bat/cell.html

Thank you for the site..........

No, Kockums stealth subs use batteries charged by diesel or stirling engines.

They're quiet. There are times that you don't want a steam turbine whizzing around, shedding an identifiable vibration into the water, even on a nuclear sub. Think about it.

Industrial fork lift batteries come in 48 volts. They may be approximately the same as as the sub battery.

Not even in the same country, you are WAYYYY off.......!!!

I forgot to mention, a single cell (2.2volts) would probably weigh 500-700KG or more EMPTY!!!! More than a forklift truck complete!!!

A industrial forklift battery 48 volts at 1020 amp hour will weigh 3864 lbs.(1752KG)

Thats 48+ KWH.

Not as big as the battery he is listing. Then again demand for them is more I would think so than submarine batteries. So they may not be as pricey per KWH of storage.

Most lift trucks I have had to work on the little ones will pick up 2500KG.

That is a far bigger battery than I imagined.

The sub batteries are usually one cell, not a complete battery, he only has I believe 6 cells and 12 volts nominal....they are big and very heavy....

I don't understand your concern about 12 volts. I've been off grid for over seven years now and am using 24 volts without a problem. Most deep cycle batteries that are used for off grid systems are of the 6 volt type and are connected in both series and parallel to get the desired voltage. The higher the voltage the less line drop and the smaller the wire size required which quickly balances any cost problem of 12 volt equipment. I use a center tap on my battery bank to get the little 12 volts I need and an equalizer to keep the batteries balanced. Perhaps there are other considerations that you have that we are not aware of that makes a 12 volt system better for your application.

I'm starting to lean towards the Forklift set of batteries now due to the fact that Forklifts are more common than submarines in my world.

Otherwise I went through some of the same thinking as far as the electrolyte was concerned, and was embarrassed about that.

Turns out that that misconception applies to fuel cells.

I'm still doing parrallel research as far a batteries and fuel cells are concerned.

I took great notice of the fuel cells run off a genetically engineered bacteria that turned sewage into the fuel for the cell, just announced on Globalspec.com.

The little nation of Denmark and Greenland their Protectorate is a "hotbed" of practical applications of the techologies from what I can tell so far.

I'd be inclined to do whatever they do, though you can't really go wrong with submarine batteries if you can get them and move them since they are heavy and have been around for a good while now.

I guess the detraction is that submarines are not as common as forklifts.

Thanks for the discussion. I've been drawn into globalspec & CR4 because of my interest in batteries.

There is a web site concerning the charging of lead acid batteries, using an imposed high frequency on the charge voltage. This is claimed to break down sulphation on the plates, there are now lots of "battery minders" coming on the market using this principle. I have tried one of these quite successfully on a pack of sealed batteries on a wheel chair. it is also claimed old batteries can be rejuvenated.

I read somewhere that "NIFE" batteries are better than lead acid types. lasting 50 years or more with proper maintenance.

GF

This is very interesting as it was one of the key questions we worked on in the multipole battery. Due to the simultanous charge and discharge function in the battery, there was no sulfation of the plates. We were trying to draw the same application parrallel for off-grid solutions in rural african villages.

Simultaneous charge and discharge? What are you on about? If you have the energy to do so, bypass the battery altogether and leave it full. This will also avoid sulphation. And cycling, for that matter.