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battery revitalizers, reconditioners and such Options
davisonh
#1 Posted : Wednesday, February 11, 2009 10:21:14 PM
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Oh yea,the many scam artists out there preying on common folk,not that they know any more or less than you do about it,but they will still try.You ask and I shall answer,yes you can extend the life of a common lead-sulfuric acid battery by doing two things,first and most important make sure you  have a clean charging current(no AC 'ripple' or less than 1/4 of 1 volt,in other words charge your batteries @ a true 12 volts not 13.6 volts on a car.)and 2,and this is a little counterproductive but cut your charging rate by a third.See on a 12 volt battery they are divided into 6 two volt cells and pretty much all lead acid battery cells are two volts.This is because this voltage is what the dielectric strength of the chemical medium(of lead-sulphuric acid) can safely handle without 'boiling over'.Boiling over is when too high of a voltage is impressed across the lead plates,eventually they will 'sulfate';boiling the chemical medium away, warping and shorting the plates and prematurely destroying the battery.Excessive charging and discharging does the same thing to them but instead blows holes in the lead plates eventually shorting them or rendering them useless.Unless there is something that can turn lead sulfate into sulfuric acid again you're out of luck jd.Now majere has had limited luck reversing the polarity but in order to do so you have to disassemble the battery and use a 'reversing chemical',but he said his luck was very limited,the batts did not last very long.

jd
#2 Posted : Thursday, February 12, 2009 5:33:01 PM
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So, other than being precise with and letting up on the charge rate, there's little I can do?  I have killed enough batteries to warrant a rap sheet.  This has gotta stop.  I am picking up 8 very heavy duty 'transit bus' batteries next week.  12 volts.  255 ah.  Deep Cycle.  I'll wire them in as 2 banks of 48 volts (my system is 48v) getting 500 ah as a result.  What should I charge them at?  Amps?  Float?  Max?  Duration? 
I have a multi stage charger (Outback) that I can crank as high as 18 amps.  I am currently charging at 13 amps for an hour a day.  That takes me to about a 50.0v level and I hold that for about 24 hours.  Then I am at 48.0v and I put on the genset again.  I try never to get below 48.0v. 
The charger is set for 61 volts but it gets up there only for a few minutes and then I shut her down. 
The batteries I am doing this to are 8  six volt batteries at 225ah.  But I can sense they are not holding a charge as long as they did when new - 4 years ago.
I would like to get some old, large 2 volt (like Surrette) but can't afford them new and don't know where to look 2nd hand.  Plus I live a long way by boat from industrial places. 
Any tips would be appreciated.

     
davisonh
#3 Posted : Saturday, February 14, 2009 1:55:58 AM
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That 61 volts sounds pretty excessive for a 48 volts system jd and although you will put in more current for only a few minutes that comes at a cost.I don't remember the formula off the top of my head but I know that when one raises the voltage across a battery bank by more than 2% of its rated voltage the rate of sulfation is cubed in it's increase.The sulfation is what destroys the batts prematurely.So 61/48 = 1.3 times the rated charge pressure(voltage) which is 21.4%  over its nominal 48 volts.So ya,you're going to trash your batts eventually doing that on a daily basis.Try charging @ 9 amps for two hours a day @ a dead on 48 volts when not charging off the panels,13's a little excessive.They wont boil but on a hot day they'll want to.Check your batts with a hydrometer too,the new ones should be hopefully optimal, if they're not don't use them ,as you problably know a couple of bad cells will ruin your day when discharging.Your old ones problably are;the plates and the electrolyte are wearing out.You're getting  a buildup of lead sulfate on the cathodes of your 2 volt cells.That causes internal resistance in the individual cells.They'll also hydrogenate(create more hydrogen)more as they get older.What you can do to get a real reading(if you don't have one already)is use a carbon pile load tester on your six volt cells.This is a device sold at your auto supply stores and what it does is throw a fixed load across your supposedly fully charged cells.Its voltmeter is coded to show 'Good''Fair'"Bad'.This is where nickel cadmium batteries are better for long duration stuff,they need to be charged evenly and can't handle heavy charge/discharge cycles but dayum they last forever,20-25 years sometimes.I would keep your charger on 'duration' all the time.I hear a lot of people saying 'Oh yea 13.6 volts is a good charging rate on a car' and I always think to myself 'yup,and you'l be replacing that battery in 5 years'.If your batteries fall to 46 volts thats ok too I've always said +/- 2 volts(basically one 2 volt cell!)preferably in the middle with dead flat DC(no ripple).If you're interested and you have acess to one grab an oscilloscope,hook up GND to the - and SIG. IN to the + at the 50 volt scale(usually they're made to handle 1000 volts or more)and most likely you'll see what I mean by bad ripple.Go up to the 1 volt resolution scale and you most likely will see a lot of spikey shooting bar graph lines and they'll go really fast.Thats AC noise or ripple.There should be none whatsoever.Try it is all I can say.If you see noise like that try getting some big capacitors,like 108 MFD @ 50 volts,put 2 in parallel across the output charging lines,that'll help with the noise.

jd
#4 Posted : Saturday, February 14, 2009 8:41:57 PM
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Posts: 134,494
Hmmmmmm..........some of that went over my head, Dh but I did reset my battery charger.  The charge rate is now 10 amps.  The absorb is 52.0 vdc
The Float is 52.0 vdc
The refloat (whatever the heck that is) is 50.0 vdc
The Equalize rate is 58.0 vdc.
I tend to run the charger from the genset for an hour or two but, of course, the PV array (80 watts at 48volts) and the soon-to-be erected wind gen are always 'on'. 

The bank, of course, is 48 vdc and the amp hours are 225.

The new batteries coming in should be set at what?  They will be set up (2 banks of 250 ah) as two banks of 4 x 12 volt = 48 volts @ 500 ah. 

I am thinking I should isolate the old bank and use them differently.  And I will go buy one of those carbon pile load testers.  Any brand name recommendations?  Rough idea of a reasonable price? 
 
davisonh
#5 Posted : Sunday, February 15, 2009 12:01:16 AM
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(shakin head)g*dayum electrical engineers,lol.I hate when they fool around with nomenclature on the front of your panel in order to get a few more bux for a charger,grr(whack dem upside da head!)(sigh)oh well okay,enough rantin,okay 52's too much, gotta keep them charging at 50 volts only,god they make it sound like rocket science,lol.Float charge is when the batterys starting out pretty much discharged to 0%(the little balls in da hydrometer 'float' when it starts charging,umm refloat means recharging,umm same thing(whacking my plastic electrical engineer to the right of my 'puter,lol).Equalize is BS,thats the cutout voltage when the battery banks' full and they're always set way the  heII too high so you'll cook your batts.The 10 amps is in the ballpark I don't think a volt or less will boil them too much as I say,it's ok to let your batts get below  the rated 48 volts too by a couple of volts.I say since you have a larger bank keep the initial charging rate at 10 amperes/hour only,esp. big huge deep cycle lead acids,they don't like severe charging rates.Once your heavy base charge is in the cells(and it may take hours to get there @ 10 amps but its worth the time,looking at the meter will tell you when it's there.) a 10 amp 2 hour daily recharge(assuming the solars are not on)will be all you need for daily use.

Load testers are pretty cheep,theres not much to them,prblably $25-40 for one.I would take out each cell and test each one before use.You might just have one bad six volt cell.

jd
#6 Posted : Sunday, February 15, 2009 5:51:43 PM
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Thanks, Dh.  All set.  But I may have already killed my first bank, eh?  What with all that charging up in the big numbers?  What I don't understand is why I can't charge at 50 volts but a gazillion amps?  The charger is a five stage charger and it 'tapers' the charge anyway so cranking the amps should be OK, no?  I have set it at ten but surely it can take 15 or 18 (max) until the 'taper' kicks in, no?
davisonh
#7 Posted : Monday, February 16, 2009 1:25:21 AM
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Posts: 134,494
The only way you can see if you trashed your first set is to charge the bank up,then unwire each 6 volt cell(or 2 6 volt cells in series if your carbon pile load  tester tests only 12 volt cells)take it out of the bank and throw the carbon pile tester across + and - and see what the meter says.I'll almost guarantee most of them will be all right except for one,lol..some reason thats the way it always seems to work out.Okay the reason you can send  a billion amps(lol) through the cells but not any more or less than 1 or 2 volts over the banks goes back to the dielectric strength of the electrolyte,sulphuric acid can only insulate between the lead plates at a maximum of 2.2-2.4 volts *only*! No more or less than that or they will boil,again weakening the solution,thereby breaking down the  resistivity of the solution,hereby shorting or blowing holes(kinda like arc welding underwater)in the plates in each 2 volt cell.Its the same reason you can touch the terminals of your car battery that has 400 or more amps in it.At a pressure of 12 volts the current will never be able to go thru your body(anything 50 volts or more will go thru your body and shock you!)About the taper,make sure it doesn't 'pulse charge' because I found that pulsing tends to do the same thing as heavy current charging.When one turns a switch 'on' either in AC  or DC a current surge of up to 4 times the rated amount of current thats supposed to flow thru the circuit happens for a a second or less.When one disconnects a switch,especially under load,the resultant 'break' causes a small arc,this arc is caused by an instantaneous collapsing magnetic field around the wire and the switch resulting in a one second or less high voltage of hundreds of volts at 120 volts.When you do this every 20 seconds on a charging battery it tends to really shorten the life of the battery.As I say the battery industry really is 'sewn up' when it comes to planned obselescence and a lot of work needs to be done to change the industry I think.
jd
#8 Posted : Monday, February 16, 2009 9:46:00 PM
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SOOooo.................if my 5 stage tapering charger is not a 'pulser', does that mean I can crank up the amps?  I can only go to 13 with my small genset anyway, 18 with my big one.  So I left it on 13 before we began this thread (now it is at 10.0 amps) so that I could alternate between gensets as the rest of the working load determined (sometimes I am running a washing machine or table saw and then I use the big genset). 
I have the charge rate at 54v.  Is that still too high?  52v? 

dc   
davisonh
#9 Posted : Tuesday, February 17, 2009 12:00:03 AM
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Posts: 134,494

No you're doing it right by running the heavy loads with the generator and the lights,etc with the battery set.No 48-50 volts is best,remember upping the pressure on the battery bank doesn't necc mean more amperes into your battery but it does mean less time to put the amperes into the battery.Set it @ 10 amperes/hour max @ 50 volts,no more no less.If your battery bank voltage drops to 46 volts,thats ok,it'll actually help the batterys along a bit by keeping the sulfation rate low.High voltage frys batteries bigtime.Yes you can up the amperes but you have to keep the voltage level the same,no more than 50 volts max and I would'nt make it a habit of upping the amps a lot if you can because as I said before that has its detriments too.

jd
#10 Posted : Tuesday, February 17, 2009 12:00:03 AM
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Posts: 134,494
Some loon on the local tv got a good bit of publicity about his magical, secret way of revitalizing 'dead' batteries.  Send $99.00 for the 'secret'.  Because the tv did the exposure and said it was 'great', I fell for it.  I am $99.00 lighter and this doofus told me the secret.  "Go to junkyards and get dead batteries.  Not all of then are dead.  Charge them all up real good for 48 hours.  Then 'shake ém' a bit.  Like maybe put them in your pickup bed and drive around for awhile -that kind of thing.  Then charge them again with a 'batterymiser' attached.  This device will keep ém good.  There you go.  Thanks for the money!"  I have punched people for less. 

I am not happy.  Still, I have blown $100 in stupider places (women come to mind).  Bought a lava lamp once.  I will recover.  But it seems to me that there must be something out there that extends the life of batteries.  Is there? 

I already have a pulse-meter but that is not the answer. 

Davh............you there?


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