Alum Pb batteries

robintrobint Registered Users Posts: 10
Hi y'all

I'm hoping that this site has many sensible contributors who have at least some formal technical education. I am so weary of reading specious rubbish on the subject of batteries written by people who have no formal education at all. I've spent a long time searching into Pb acid batteries and how to recover them. Its open season for snake-oil salesmen. Yet the LAB is fundamental to off grid storage - indeed it is the Achilles heel of the system, I'm sure you'd all agree.

Does anyone give any credibil;ity to replacing h2so4 acid with saturated alum/water paste (various types are used Potassium/sodium/ammonium aluminium sulfate)

I dont understand how it is supposed to work - though it appears to need to start with fully conditioned plates (PbO and Pb)

It has an oc of 11.6v and can be taken down to 6v in a 12v stack without damage? allegedly

Its Ah capacity is supposed to be simillar

My immediate thought was that if they are so darned good why arent lots of people using them?

I cant find any drawbacks cited

So if its too good to be true then it cant be.

Anyone any honest experience/links etc

Cheers

Robin
«1

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    In general, almost any mineral contamination is bad news for Lead Acid batteries:

    http://www.trojanbattery.com/pdf/WP_EffectOfImpurities_0612.pdf

    Obviously I am not a chemist... I was typing about Aluminum--Not Alum... Remove post.

    -Bill "not a chemist" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Alum Pb batteries

    "Alum" is a specific chemical compound (or family of compounds), specifically hydrated potassium aluminium sulfate (potassium alum) with the formula KAl(SO
    4)2·12H2O.
    Let me try to clean that up: KAl(SO4)2·12H2O

    That is water soluble. In fact, being a hydrate it carries a certain amount of water with it at all times. :)
    SMA SB 3000, old BP panels.
  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    Sorry, yes it was Alum not Aluminum....

    This forum seems to have a lot of people actively experimenting over the years:

    http://blog.hasslberger.com/2007/01/how_to_convert_a_lead_acid_bat.html

    I did not see any actual numbers on battery capacity after conversion (i.e., if started out at 6 volts 220 AH ended up at xyz AH at 20 hour rate).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Alum Pb batteries

    Welcome to the forum Robin.

    I think you answered your own question:
    robint wrote: »
    My immediate thought was that if they are so darned good why arent lots of people using them?

    Any solution that is either acidic or alkaline can be used as an electrolyte. How effective it is, both in terms of action and economics, is another matter.

    For example there are such things as aluminium-air batteries, but most people would not pony up the money or deal with the issues. Lithium batteries have had the same issues, but are getting better. Sometimes it isn't the science at fault but the economics.
  • robintrobint Registered Users Posts: 10
    Re: Alum Pb batteries
    Welcome to the forum Robin.

    I think you answered your own question:



    Any solution that is either acidic or alkaline can be used as an electrolyte. How effective it is, both in terms of action and economics, is another matter.

    For example there are such things as aluminium-air batteries, but most people would not pony up the money or deal with the issues. Lithium batteries have had the same issues, but are getting better. Sometimes it isn't the science at fault but the economics.

    Almost all of the sites I visited including Hasselberg, are of a speculative nature and technically illiterate - to be blunt. All shy away from quoting real facts and comparative test results. Many are trying to sell fancy chargers called Tesla or Radiant or Pulse at inflated prices or some snake-oil additive that miraculously cures your dead battery battery.

    We all know that any two dissimilar metals/compounds will produce a voltage when immersed in a conducting fluid eg CU and ZN in a glass of tap water (with a tiny pinch of salt to improve conductivity - which is why your food tastes better btw). How well this will function as a battery depends many factors and the chemistry begins to lose me.

    Back to our deep cycle Lead acid battery (LAB). Clearly for starters there is a conflict of interest between manufacturer and customer Specific life (No of Cycles) and longest usable life. For example cheap batteries are made from very thin plates and these are crammed into the very bottom of the battery compartment. This leaves no room for the inevitable accumulation of shedded plate material and this soon shorts out the cell so its useless. Early Plante cells seen in glass jars alway had plenty of draft at the bottom of the jar. Also they were designed so you could easily pull the plate pack out for cleaning and reconditioning. Many of these cells have lasted 50-70 years - wouldnt the PV man be delighted with this kind of service. If plate shedding is one of the failure mechanisms, then why not arrange the plates horizontally? Is this just too obvious?

    ALUM there are several different types available which have been tried - Potassium Alum, Sodium Alum, Ammonium Alum. No one quotes any comparative figures but they all work (allegedly) with Ammonium being the favourite. They are all cheap. Epsom salts mg sulphate is used to reduce the electrolyte conductivity but its only a short lived fix as the ions get taken up on the plates. So the experimenters claim that a badly sulphated battery can be recovered by swapping the acid electrolyte for saturated alum solution (almost a paste in one video. They then go on to claim that the battery runs good as new (but for how long?) and doesnt suffer sulphation and can be deep discharged down 80% without damage Some claim years of extra life, but nothing is backed up by any credible figures. All too good to be true? Why arent we all doing it?

    I was hoping that maybe some PV guy had tried this on his old battery bank

    I havent found any credible scientific discussion on this

    As a last resort I will go back to basics and start with some 4" squares of lead sheet in a jar and make some comparative measurements, try creating the sulphation problem and see what alum does

    BTW all the youtube vids on the subject are presented by delusional charlatans. None of them makes any attempt to measure battery Ah capacity (ie measuring current vs time rather than voltage) fundamental error from the mentality of 5 year olds IMHO.

    So Im hoping someone in the PV community can enlighten me

    Robin
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Alum Pb batteries

    Trying to rejuvenate an old battery by any method is a crap shoot. Plates become permanently coated with sulphur, plates erode, plates oxidize. How reversable are any of those factors? Not very. So you have just as much chance bringing one back to life by draining it, rinsing it, and refilling with sulphuric acid solution as alum solution.

    There are no miracle cures for dead batteries. I've seen this sort of thing promoted for half a century now and the 'proof' has always been anecdotal, not scientific.
  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    Yep--More or less, almost all I have visited are thrilled that the battery "accepts" charging current and is not "dead" 24 hours later. Virtually none go on to measure anywhere near standard battery performance tests (connect an AC inverter to an electric heater or bank of lights, and run the battery for 10 or 20 hours and see if the battery has 5%/50%/100% of original AH capacity. Only a very few even say that the battery is still being used 1 year later.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Alum Pb batteries
    robint wrote: »
    If plate shedding is one of the failure mechanisms, then why not arrange the plates horizontally? Is this just too obvious?

    Already done by tightly wrapping tppl into spirals, or high compression of flat-plates. Enersys, Hawker, and even Optima can tell you all about it. 1985 time frame.
    They then go on to claim that the battery runs good as new (but for how long?) and doesnt suffer sulphation and can be deep discharged down 80% without damage Some claim years of extra life, but nothing is backed up by any credible figures. All too good to be true? Why arent we all doing it?

    yep - back to 1998 or so when LAB (agm specifically) for EV was vying as a competitor to nimh. Required an IUI charge profile for 80-100% DOD, which no consumer had on hand, nor was available for purchase in decent numbers.
    As a last resort I will go back to basics and start with some 4" squares of lead sheet in a jar and make some comparative measurements, try creating the sulphation problem and see what alum does

    Why waste your time? You can avoid sulfation in it's entirety by going Li-ion. Choose your sub-chemistry for safety, which is currently LiFepo4. One reason you can have it under your motorcycle seat. Hobbiests may use the wrong chemistry and give li-ion a bad name because they are taking risks with anything more energy-dense and unstable than lifepo4. (Like Lico02 chemistry).

    Experimentation is good, even for 'ol lead-acid. But if there is nothing but talk, and nothing brought to market, it doesn't matter. Most of the talk is usually an endless thread of opinions, or weak attempts to disguise themselves as seed for investor pitches.

    Many so called new battery discoveries, are merely a way to stuff a patent-portfolio warchest, with no real intent on producing the product brought to life in the lab.
  • robintrobint Registered Users Posts: 10
    Re: Alum Pb batteries
    BB. wrote: »
    Yep--More or less, almost all I have visited are thrilled that the battery "accepts" charging current and is not "dead" 24 hours later. Virtually none go on to measure anywhere near standard battery performance tests (connect an AC inverter to an electric heater or bank of lights, and run the battery for 10 or 20 hours and see if the battery has 5%/50%/100% of original AH capacity. Only a very few even say that the battery is still being used 1 year later.

    -Bill

    A healthy dose of scepticism is ok with me. I am a retired professional engineer and I wish to see if there is a trace of useful practice that can be gleaned from all the hokum. I will offer to publish my test results in a scientifically accepted manner (no BS). I have an interest in recycling deep cycle batteries used in mobility scooters.

    You PV guys have a particular problem cos of the nature of your solar availability. You will be aware that LABs hate being half discharged and partially recharged for long periods. Its a recipe for early hard sulphation. How do you guys deal with this problem if you dont have grid. Firing up an expensive diesel alternator to fully recharge your batteries for say 10 hrs cant be the answer. It must be one big headache?

    Most of the work done on LABs never seems to involve dismantling the battery, so what ever they think they are doing is highly speculative. Agreed this wont work for automotive batteries cos of their flimsy construction, but stationary batteries that havent been abused? Forklift batteries are frequently dismantled and reconditioned. Of course how they actually do it is a closely guarded secret, but not too difficult to guess.

    One of the big cons in the EV market is the use of gel cells or AGM cells with VLRA valve release. Supposedly the gases recombine to make water. Well I have just resurrected a 40Ah gel cell which had gone dry. I topped it up with rain water + small qty epsom and its on its third charge discharge cycle and I get ca 30Ah on C20 rate. This is supposed to improved with cycling. Prior to this the cell was dead and wouldnt accept a conventional dc charge. I zapped it with a square wave pinger up to 60v for half a day. With the added water it suddenly seemed to come back to life. I will publish the graph 15.5 hrs @2A down from 12.5 to 10.5Vdc

    If this really works, there has to be something in it of use cos Ive just saved myself £100 for two batteries (the other one wasnt so bad.

    So guys, be sceptical, find fault with my methods - most welcome and I am not selling anything BTW

    BTW I hope you all know that distilled water has a very high resistance ca 20Mohm-cms
    http://forum.allaboutcircuits.com/showthread.php?t=18893
    but this fall rapidly with the minutest amount of impurities added such as common salt

    He might be right about electrocution greater in pure water, but in practice you never get really pure water for very long (it wont boil for a start)

    You can get an electric shock from a 12v battery in a marine wet environment - try it - wet you hands with very salty water and swipe your knuckles across the terminals

    Cheers

    Robin
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Alum Pb batteries

    Many of us off-grid aren't in a marine environment. Instead of powering up a big gen when the sun doesn't shine we fire up a small one - as small as we can get away with - and only charge to where it's practical. Basically anything over 75% SOC will keep sulphation at bay. Even so you have to do a full charge now and again. But yes, these partial cycles count as cycles and eat in to battery life.

    GEL's aren't really suited to RE use because they are so picky. AGM's can be much better because they are so current tolerant, but they lack the ability to check SG and cost quite a bit per Watt hour. FLA's are still the ol' standby and make things easy and cheap for most people. Other battery technologies are for the most part only for experimenters; you'd better know what you're doing if you're going to use lithium or NiFe.

    Yes, distilled water is practically a non-conductor. Tastes horrible too. :D
  • robintrobint Registered Users Posts: 10
    Re: Alum Pb batteries
    PNjunction wrote: »
    Already done by tightly wrapping tppl into spirals, or high compression of flat-plates. Enersys, Hawker, and even Optima can tell you all about it. 1985 time frame.



    yep - back to 1998 or so when LAB (agm specifically) for EV was vying as a competitor to nimh. Required an IUI charge profile for 80-100% DOD, which no consumer had on hand, nor was available for purchase in decent numbers.



    Why waste your time? You can avoid sulfation in it's entirety by going Li-ion. Choose your sub-chemistry for safety, which is currently LiFepo4. One reason you can have it under your motorcycle seat. Hobbiests may use the wrong chemistry and give li-ion a bad name because they are taking risks with anything more energy-dense and unstable than lifepo4. (Like Lico02 chemistry).

    Experimentation is good, even for 'ol lead-acid. But if there is nothing but talk, and nothing brought to market, it doesn't matter. Most of the talk is usually an endless thread of opinions, or weak attempts to disguise themselves as seed for investor pitches.

    Many so called new battery discoveries, are merely a way to stuff a patent-portfolio warchest, with no real intent on producing the product brought to life in the lab.

    I cant fault your logic sir, but for one issue - the environment.

    Having these LABs deliberately engineered to fail and end up as scrap is surely unacceptable. The LAB is likely to remain by far the cheapest form of electrical storage. Lion is 10x cost so far
    If it is possible to recondition stationary labs particulary for PV use then there has got to be value in pursuing this line - given so much BS to clear out of the way once and for all.
    For my use the wet cell is half the price of a gel cell and much better suited, but try and buy a deep wet cell for EV use? I am working on it. Just because I believe there's a conspiracy, doesnt make me wrong.

    I'll bet there are many PV guys out there who would love to hear a proven method to recondition their failing battery banks. Think - the Pb doesnt go anywhere or evaporate. Its still there to be re-used
    I remind you all, I am not selling anything. In my area of mobility scooters, the market is chock full of cowboys charging 5x the true price on naive seniors (same applies to golf carts)

    For example my electric bike's lion cells and showing age after 4 years, maybe down to 60% but still useable for my short journeys. A new battery pack costs nearly £500 which is half the cost of a new bike. I can re-cell the battery pack myself with AA cells from ebay for ca £100 so you see the gross markup (rip off) involved

    BTW, often misquoted, but Pbsulphate is poorly soluble in water but interestingly it is soluble in caustic soda? and of course EDTA

    The conspiracy thickens

    Robin
  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    We do have some threads on reconditioning AGM batteries:
    BB. wrote: »
    Here is a thread how one company (Concorde) recommends to "recover" their AGMs... Not supposed to apply to any other brands of AGMs:

    Sulfated Lifeline Concorde AGM Batteries

    And here is a great thread from DapDan with information on how one place recommends to restore AGM batteries (new catalyst caps, adding water to cell, etc.):

    Low rest voltage on GNB absolyte IIP cells

    In the end, trying to do "extreme" things to batteries should be done in a safe area and always under some sort of supervision/monitoring (don't want to overheat the cells and blow acid around) and performed while wearing appropriate safety gear/gloves/face shield/water/hose/baking soda nearby/etc.).

    And--if the cells are otherwise scrap--if you can try some of the above things (if done safely)--you are not loosing much anyway.

    -Bill

    And find the threads started by user "Adas" from Hawaii--We have not heard from him for a while, but he went off grid with a fabrication business using reclaimed fork lift batteries... For example, getting 36 volt batteries, wiring around "truly dead" cells, then having 24 volts left for his 24/48 volt AC inverters+solar charge controllers... He was very happy with his results:

    http://forum.solar-electric.com/search.php?do=finduser&userid=1074&starteronly=1&contenttype=vBForum_Thread

    I don't think it is necessarly true that battery mfg. are so much making cells designed to die early--Perhaps it is, at least as much, consumers that want to buy their golf cart batteries at $88 each--And not by the same battery for $200 that may last 5x longer (whether high quality Lead Acid or Lithium based cells).

    One of the problems with battery banks is that they can be "killed" pretty easily (over discharging, not watering, watering with contaminated water, over charging, early cell failure takes out rest of bank, etc.). If you are going to kill a bank in three years "accidentally"--Then it may as well be a cheap bank.

    Regarding sulfation--It appears that many of the sulfation issues revolve around a battery unused at less than ~75% State of Charge... So, the idea has been to recharge the battery back over 90% every few days and avoid going below ~50% state of charge (with "typical" flooded cell LA batteries).

    However, there is another operating cycle/method. Basically cycle the battery between ~50% to 80% state of charge, and bring >90% at lease once every 10 days (one vendor engineer suggested every 28 days maximum--But I am not sure anyone is eager to test that on their battery bank just yet).

    As long as the battery is cycling through that 50-80% state of charge, sulfation is not a major concern (sulfation, corrosion, etc. are always concerns--Just not a major factor in early life death--In this example).

    You may even gain battery life... Battery is more efficient charging during the less than ~80% state of charge, less electrolysis--So less oxygen corrosion on the positive plate, batteries should run cooler, etc... However, you are still looking at sizing your battery bank 4x your daily load--Not saving money on batteries used vs rated capacity.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Alum Pb batteries

    No conspiracies, just science - and economics.

    Back in the dawn of time when I were a lad FLA's could be taken apart, rebuilt, and put back together. This made for an environmentally-friendly battery, even though we didn't have that term then. Mostly it made for an economically-friendly battery: as with so many things in that era the attitude was "fix first, replace if needed". But that attitude changed, along with battery design. You can debate forever which is the chicken and which the egg, but the result was cheaper mass-produced batteries that could be replaced for far less than they could be rebuilt.

    Now that the environment has entered the picture and people are waking up to the very real cost of turning vast areas of the planet into uninhabitable toxic waste heaps the attitude should be reversing. But sometimes it takes a lot of effort to get people to change. Perhaps we will get back to making serviceable batteries rather than disposable ones. At least they are recyclable.

    Edison's NiFe cells have been around about as long as lead-acid but are not much in favour due to practical issues: they take up more space for the power delivered and require periodic electrolyte changes (neither simple nor neat to do). They too can be recycled.

    Lithium batteries offer great promise in performance, but still have usage issues (you must keep cells balanced for example) as well as not being able to be rebuilt. They too are recyclable despite being arguably more toxic than lead-acid.

    But the notion of simply rejuvenating a battery by pouring some magic solution in it is snake oil and always has been. The reasons being as I stated: you never know what is wrong inside the battery. So it is a gamble that emptying, flushing, and refilling with anything will bring it back to life. And if it does so, how much life? Another gamble. You can apply a hard charge to a dead battery and it will appear to be back to normal based on Voltage alone, but when you connect up your load you may find your 200 Amp hour battery now has a real capacity of 2 Amp hours.

    I sure wouldn't want to rely on any such 'miracle cure'.

    Still waiting to see one of these salesmen explain the chemistry behind how any of this stuff removes hardened sulphur, restores corroded and eroded plates, and truly brings the battery back to life.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Alum Pb batteries

    Thousands of people have been beating this dead horse for a hundred years, and still the poor thing refuses to pull a plough across the field.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Alum Pb batteries
    robint wrote: »
    Having these LABs deliberately engineered to fail and end up as scrap is surely unacceptable. The LAB is likely to remain by far the cheapest form of electrical storage. Lion is 10x cost so far

    Actually, the world is pretty set up for Pb recycling, whereas they aren't for Li-ion. Although a Li-ion (specifically lifepo4) contains a minimum amount of toxic materials, recycling centers to garner up the plastic and copper from the cases may get rejected. Thus, touting low toxicity, many users both residential and commercial will just toss them in the trash ending up alongside the plastic bottles in the landfill.

    The 10x price is coming down, and in fact when compared to a quality agm, is nearing parity for *low rate* cells that most solar users with a house-bank would use. GBS LiFeMnPo4 cells are one example. Still up there, but the li-ion topic is discussed elsewhere.
    For my use the wet cell is half the price of a gel cell and much better suited, but try and buy a deep wet cell for EV use?
    Nobody in their right mind would use a wet cell for EV use these days, much less an e-bike - just for the low energy-density issues alone along with overall weight.
    I'll bet there are many PV guys out there who would love to hear a proven method to recondition their failing battery banks.
    Not really. Batteries age, and even if you can recondition them to hold a voltage, due to age they just won't hold a load for very long. Time for new ones. Plus load requirements change over time. A 50-year battery may be great, but it may not have enough capacity for your new loads 10 years down the road and you end up replacing them anyway.
    In my area of mobility scooters, the market is chock full of cowboys charging 5x the true price on naive seniors (same applies to golf carts)

    Then you'll love this non-commercial site - although not ebike, you'll get some related info, especially on batteries both LAB and LiFePo4. From people who live ON them every day:

    http://www.wheelchairdriver.com/
    and the forum:
    http://www.wheelchairdriver.com/board/
  • robintrobint Registered Users Posts: 10
    Re: Alum Pb batteries
    BB. wrote: »
    We do have some threads on reconditioning AGM batteries:



    And find the threads started by user "Adas" from Hawaii--We have not heard from him for a while, but he went off grid with a fabrication business using reclaimed fork lift batteries... For example, getting 36 volt batteries, wiring around "truly dead" cells, then having 24 volts left for his 24/48 volt AC inverters+solar charge controllers... He was very happy with his results:

    http://forum.solar-electric.com/search.php?do=finduser&userid=1074&starteronly=1&contenttype=vBForum_Thread

    I don't think it is necessarly true that battery mfg. are so much making cells designed to die early--Perhaps it is, at least as much, consumers that want to buy their golf cart batteries at $88 each--And not by the same battery for $200 that may last 5x longer (whether high quality Lead Acid or Lithium based cells).

    One of the problems with battery banks is that they can be "killed" pretty easily (over discharging, not watering, watering with contaminated water, over charging, early cell failure takes out rest of bank, etc.). If you are going to kill a bank in three years "accidentally"--Then it may as well be a cheap bank.

    Regarding sulfation--It appears that many of the sulfation issues revolve around a battery unused at less than ~75% State of Charge... So, the idea has been to recharge the battery back over 90% every few days and avoid going below ~50% state of charge (with "typical" flooded cell LA batteries).

    However, there is another operating cycle/method. Basically cycle the battery between ~50% to 80% state of charge, and bring >90% at lease once every 10 days (one vendor engineer suggested every 28 days maximum--But I am not sure anyone is eager to test that on their battery bank just yet).

    As long as the battery is cycling through that 50-80% state of charge, sulfation is not a major concern (sulfation, corrosion, etc. are always concerns--Just not a major factor in early life death--In this example).

    You may even gain battery life... Battery is more efficient charging during the less than ~80% state of charge, less electrolysis--So less oxygen corrosion on the positive plate, batteries should run cooler, etc... However, you are still looking at sizing your battery bank 4x your daily load--Not saving money on batteries used vs rated capacity.

    -Bill
    Many thanx for the links, It took me some time to read thru and absorb

    The pros and cons of AGM vs conventional flooded will roll on, its horse for courses. I think if I were a PV guy in the outback, I would want the simplest solution which can be maintained. I want to be able to take hydrometer readings, I dont mind topping with rainwater. I want to be able to withdraw the plates and dissemble for cleaning. I want the plate mounted horizontally (I think) with room for plenty electrolyte

    Yes I wont have the same power density but Ive plenty of space and my batteries may last 20+ years who knows?

    The bottom line here is that no one has seriously tried an Alum electrolyte. It may be snake-oil but there's just too much anecdotal evidence to show it working (but how well?)

    BTW can anyone explain to me why a battery oc voltage straight off full charge will be somewhat higher than the theoretical 2.1 vpc. Why does it take several hours to settle down?
    Whats really going on with the chemistry, is it polarisation from minute gas bubbles for example?

    Cheers

    Robin
  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    More or less, the resting voltage of a Lead Acid battery is related to Specific Gravity--It takes time for the high SG electrolyte next to the plates to diffuse throughout the battery structure (at least as I understand):

    http://forum.solar-electric.com//showthread.php?17895-Battery-Voltage-and-Specific-Gravity-Question
    SG factory levels are "variable":
    BB. wrote: »
    Here is a thread on Hydrometers and how best to use them.

    I understand that some tropical locations will use a bit weaker electrolyte (batteries will have a longer service life?).

    From this thread, the range of Electrolyte Specific Gravity seems to be:
    Specific Gravity vs Applications
    1.285 Heavily cycled batteries such as for forklifts (traction).
    1.260 Automotive (SLI)
    1.250 UPS – Standby with high momentary discharge current requirement.
    1.215 General applications such as power utility and telephone.

    As mentioned earlier, the specific gravity (spgr.) of a fully charged industrial battery, or traction battery, is generally 1.285, depending on the manufacturer and type. Some manufacturers use specific gravities as high as 1.320 in an attempt to gain additional Ah capacity, but at the cost of a shorter cycle life.

    ...

    Higher Gravity = vs Lower Gravity =
    More capacity / Less capacity
    Shorter life / Longer life
    Higher momentary discharge rates / Lower momentary discharge rates
    Less adaptable to "floating: operation / More adaptable to "floating" operation
    More standing loss / Less standing loss
    So, where do your readings fall in the above scale... And I would guess that a difference of 0.030 SG or less is nothing to panic over.

    And while there is a formula for converting from SG to Cell voltage:
    Specific gravity = single-cell open-circuit voltage - 0.845 (example: 2.13v – 0.845 = 1.285)
    Or
    Single-cell open circuit voltage = specific gravity + 0.845.

    Battery temperature, additives to battery plates, voltage measured when battery has not "rested" for 3 or more hour, etc. can all affect the readings.

    New poster "leaf" has a really nice set of charts that compare battery voltage against different rates of discharging and charging (as well as resting voltage readings). From here:
    vtmaps wrote: »
    I believe those charts are from Home Power #36, August- September 1993. Lead-Acid Battery State of Charge vs. Voltage ©1993 Richard Perez.
    Here is a link: http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf

    vtMaps
    leaf wrote: »
    Am trying to upload the charts I am using...

    Attachment not found.Attachment not found.

    attachment.php?attachmentid=3655

    attachment.php?attachmentid=3654

    I don't quite a agree with the resting voltage line (I think the voltage is a bit low)--But it shows how to estimate a battery's state of charge while operating.

    Note, where the charts "flatten out"--the room for error estimating state of charge is pretty high.

    -Bill

    So--You have the equation for SG vs resting voltage... And it has been said you can take the SG reading of an AGM/Gel battery by using a properly calibrated optical refactometer to measure SG. Only a small drop is needed--Not something I would recommend to do on a monthly basis.

    Here is a very old battery manual/rebuilding guide:
    BB. wrote: »
    Eric/Westbranch posted a link to a 1922 battery repair manual. A very interesting read and look back almost 90 years at technology and mass production (near the end are some factory photographs).

    Antique battery info (1922) (thread)

    And here is the direct link to the table of contents:

    THE AUTOMOBILE STORAGE BATTERY ITS CARE AND REPAIR

    Despite the title, also includes information on storage batteries too (Farm Lighting Batteries).

    -Bill

    Gives you appreciation for our use and recycle life style of today.

    I am not sure what advantage there would be to having plates "on their side"... They build batteries with different aspect rations (tall case, squat case). And some of the "tall cased" AGMs are specifically mounted on their sides (to keep the electrolyte a bit better distributed?).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    This appears to be the website for a Chinese caustic lead acid battery:

    http://www.guineng.com/index0.htm

    Their largest battery appears to be 12 volt @ 33 AH.

    And here is a Canadian company/website for "Silicone" batteries:

    http://www.siliconebatteries.ca/

    I think they are lead/silicate batteries--But it is not clear... An Asian mfg. translating to English (perhaps even Guineng?)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Alum Pb batteries
    BB. wrote: »
    And here is a Canadian company/website for "Silicone" batteries:

    http://www.siliconebatteries.ca/

    I think they are lead/silicate batteries--But it is not clear... An Asian mfg. translating to English (perhaps even Guineng?)?

    -Bill

    Yep.
    Ran across an 'announcement' for lead-silicate batteries in an old magazine last week. About 50 years ago. Wondered if anything ever became of them. I guess not since that's the only outlet reference I've seen in the time frame.

    There's no advantage to running batteries on their (either) side. You can do it with AGM/GEL if it facilitates mounting because there's no acid to spill. But they don't work any better. Don't do it with a sealed flooded cell either; not only could the valve be compromised but structurally they are not designed to be mounted this way (caveat: as always unless the maker says otherwise).

    Still waiting for some explanation as to why the alum mixture would rebuild the insides of a dead FLA. No science I know of can do this. Have nanobots gotten that advanced? Forgot to mention them as part of the mix.
  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    That Canadian Silicone battery--May actually be a silica battery--Or GEL type battery ("fumed silica" is mixed with electrolyte to form a gel).

    Probably not a caustic-lead battery.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 29,644 admin
    Re: Alum Pb batteries

    After reading more about the Guineng batteries and seeing "silicone" as a descriptor--I believe these are also GEL batteries. Just more marketing speak.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • robintrobint Registered Users Posts: 10
    Re: Alum Pb batteries
    BB. wrote: »
    After reading more about the Guineng batteries and seeing "silicone" as a descriptor--I believe these are also GEL batteries. Just more marketing speak.

    -Bill
    Yup a canadian site from CALGARY thats suspicious. they say the electrolyte can be used as good garden fertiliser, dont say what the plates are?

    dont say how you can buy one even

    is it bait and switch?

    if they are making 150,000 month where are they?

    its all yada yada

    That old 1922 manual on battery repair has some valuable tips (I didnt know that refreshed pb plates will heat up if left standing in air (must be kept submerged in water)

    Anyone know how you make spongy lead paste?

    The plot thickens

    Robin:blush:
  • robintrobint Registered Users Posts: 10
    Re: Alum Pb batteries

    WARNING

    On a related topic, switched mode power supplies. I have just trashed two of these with the same fault. They somehow lose volt control and over load themselves blowing the fuse. There is no output from either now and I havent time to bury into it. They were cheap PRC shoddy goods 10-15 Vdc @8A. More than enough to cope with a 12V 40Ah battery. Well something goes wrong with the control circuit cos is deal with the back emf of the battery and this seems to throw it. Its normally used for powering strings of led lamps, obviously a passive load supplied with constant voltage. Its supposed to have a current limiter but obvioulsy doesnt work with a 12 back emf. I havent got my head round the cct yet but have my suspicions

    I just thought Id post this as a caveat to others. BTW my bench psu isnt too happy charging a 12 v battery. It has gone into uncontrolled mode on two occasions, belting out 50vdc with no adjustment possible. I managed to reset it by shorting the output momentarily - drastic, but it worked. It too is a cheap PRC piece of junk.
    Clearly Im not confident in leaving such unattended, might cause a fire

    Cheers

    btw I was only charging at 2-3A CV @ 14v but it somehow ran away with itself

    Robin
  • westbranchwestbranch Solar Expert Posts: 5,155 ✭✭✭✭
    Re: Alum Pb batteries

    that electrolyte sounds like KOH potassium hydroxide or LYE which when combined with an acid makes potassium fertilizer.
    KOH is used in NiCd and NiFe batteries as the electrolyte
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Alum Pb batteries
    robint wrote: »
    I just thought Id post this as a caveat to others. BTW my bench psu isnt too happy charging a 12 v battery.

    Yes - unless the power supply is actually designed to charge batteries, you run this risk. What catches many is that they put the PS on a nearly fully charged battery, and run into no problems. BUT when they attach it to a discharged battery, bang.

    Grab yourself an Iota (our host has them) and you won't have to worry about this any more.
  • robintrobint Registered Users Posts: 10
    Re: Alum Pb batteries

    Just came across this guys

    http://visforvoltage.org/forum-topic/batteries-and-chargers/410-guineng-silicone-battery-performance-e-max-post-mortem

    Silicone batteries - defrocked!

    Robin
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Alum Pb batteries
    robint wrote: »
    Let's first keep it clear that one kind of traditional enhanced lead acid battery uses silicon in one of the plates as an additive or while others use silicon oxide (silica) gel as an additive to the electrolyte to thicken it. (GEL battery, duh)
    AFAIK other then as part of a trade name for a possibly snake oil battery silicone has no role to play in lead acid battery chemistry.
    SMA SB 3000, old BP panels.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Alum Pb batteries

    What's so suspicious about a web site being from Calgary, Alberta, Canada? It's a real place; trust me on this.
  • solar_davesolar_dave Solar Expert Posts: 2,345 ✭✭✭✭
    Re: Alum Pb batteries
    What's so suspicious about a web site being from Calgary, Alberta, Canada? It's a real place; trust me on this.

    Can you say Stampede! Quite the party I understand.
  • westbranchwestbranch Solar Expert Posts: 5,155 ✭✭✭✭
    Re: Alum Pb batteries

    Yep, last for an excessive number of days... 2 weekends and the week in between.

    BTW it follows the Williams Lake Stampede by 1 week, which is held on the weekend closest to Canada Day (July1). A much more family oriented event over 4 days. http://www.williamslakestampede.com/
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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