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Forum Index : Other Stuff : Battery Rescue?
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| brucedownunder2 Guru  Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hi Bob ,, We go that storm ,,winds wer around 75Kph ,very heavy rain ,,lasted around 30 minutes .. no damage ..Just abit of water came in under the house ,,so have to get the silicon gun out again ... This 48-24 v dc Converter, u speak about ,, could you advise me of it's particulars , and where to get one ,please.. have the 24-12 truck ones ,, .. but I'd like to 1st of all power the big battery bank off the 48v Exmork wind gennie and solar panels ,, then charge up a 24v bank for powering my 24v inverter... All the best to you and Ian .. Bruce Bushboy |
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| dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574 |
Hi Bob I think that you should'nt worried about slip ring as l have already tested on my lathe and it stand up on heavy load very well until stator got fairly warm so far l am happy with slipring performer to suit this windmill. About batteries l will cut up the one of 2 volts to see if l can play with it have fun however l aware about how to handle with batteries acid and lead in safe way. 
regard Dwyer |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Bruce The 48 to 24 volt converter is a circuit I have from a friend of mine it uses 2 fets and a current limiter, it takes up to 80 volts input and has a adjustable current output at battery voltage its not regulated volts wise though as it uses the batteries to set the output voltage so I have to try and modify it to voltage regulate a bit to. When I get it working I will let you know and give you a circuit. Glad to hear you didn't get blown off the mountain in the storm, water will dry up so not to big an issue, unless it ends up in the pantry. Have you got any performance figures on the new turbine yet, I would be very interested to know how it is going. All the best Bob Foolin Around |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Dwyer Thanks for the advice on the slip rings, I will go with them as per Phills mod for now, I may have been over cautious as I don't get that much wind here. I will pass on a bit of good advice my uncle gave me for while you are having fun dismantling a battery, DON'T PICK YOUR NOSE WHILE WORKING ON BATTERIES!!!!. All the best Bob Foolin Around |
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Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Another bit of good advice while working on batteries. Take a leak before you start. 
Chemical burns are very cruel. Pete. Sometimes it just works |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Hi all, I have been repairing/ testing a 50 amp battery charger for a friend and am embarrassed to find I know a lot less about charging batteries than I thought. I hooked it up to a bank of new batteries (after repair)and run it through a few cycles and it worked great! doing the complete absorption and float stages right down to a few mA as per the manual. The charger didn’t need to go back straight away so I decided to put it through the ringer and try charging some really stuffed batteries. I picked 5 automotive batteries, all over 7 years old (N70Z'eds) most had bad sulphation, imagine cement poured over the plates. The only thing in their favour was that they had been stored undercover and I could get just a flicker of interest from the hydrometer on all the cells. So I switched them on aaaa..nnnd yep their stuffed. went straight to float taking about half an Amp of juice. I hooked a small load in to trick the charger back to absorption mode, the voltage climbed to the mid 14v range so I left it like that for a couple of days. OK, at this point I have got some action on the hydrometer. Nothing special but all the cells have risen, so I have changed tack. I have attached a 12 Amp load on a timer( so I can set it to partially drain the batteries), then rest for a few hours, then switch on the charger. I wander past every few hours and check the voltages, run the clamp meter over all the leads to see what all the batteries are doing and take a few specific gravity readings. Its a month or so later, the charge and drain cycles are quite long now, I am draining the batteries for 12 hours at 12 Amps then charging for 24 -36 hours the batteries are taking 45 amps at the start of charging slowly declining to 4.8 Amps on float. This is indicating there is still a lot of chemical activity happening. Interestingly my 7Amp Ctek switch mode chargers still regard them as a faulty and will not run the equalize mode. I have seen some strange thing in the last 3 weeks. the acid has gone cloudy, clear, back to cloudy, gray, then dark brown clear, gray, clear. the plates have gone through the same thing with the addition of white but not in the same order, now they are turning almost black and the only visible sulphation left is the big chunky bits. The most surprising thing is the hydrometer readings they sometimes peak before I finished the charge cycle @ 1.250 then drop to 1.180 at end of charge and do the opposite as I discharge . No, its not high temps or boiling the batteries this charger has very conservative settings. I think it is caused by the sulphate reaction. At one point three of the batteries decided to use huge amounts of water I saw no visible gassing but added about 5 litres of water over a 5 hour period. where to now? dunno..... just finished another charge cycle and 4 batteries are on 1.285 S.G. they are running an 8 Amp load for 40 hours now and doing it easily, maybe another 4 weeks of this and the charger will get them to fully charged. I doubt they are up to starting and cycling on trucks and tractors, just too old. However it has got me thinking, perhaps the trickle chargers that I have on all my machines, when they are not used, are not up to the task of removing sulphate, they just slow the build-up process down. I might consider making this part of my vehicle program and rotate batteries onto a "reconditioning bank" once a year. I'm confused, no wait... maybe I'm not... |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Yahoo2 Try a desulphator as it resonates the crystals and breaks them back into acid again. I use my dc welder to get initial conduction to get things moving quicker, also when you cycle the batteries only go to 50% of the capacity so you do not reform the sulphate on each cycle. providing the batteries are mechanically sound and no inter plate shorts they can be brought back to some sort of usefulness, but not for heavy starting currents. All the best Bob Foolin Around |
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| davef Guru Joined: 14/05/2006 Location: New ZealandPosts: 499 |
Bob, I added a peak detector circuit that I saw on the web, which evidently is suppose to give you some idea of the state of the battery as it is being de-sulphated. According to the article a sick battery will show high volts like 50-60Volts and as they come back to life this voltage drops, say 20-30Volts. I I understand that you are reading the peak pulse voltage being applied to the battery. So, I measured the "peak voltage" on a battery that has one bad cell in it and I got a reading of 12.5Volts (surprise). Got out the oscilloscope and I only see 13Volts across the battery, so sign of any "peak voltages". Have you or anyone else actually looked at the peak pulse voltage across the battery? Cheers, Dave |
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| yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
thanks Bob, are you thinking of a specific desulphator? spose I should have said, all my trickle chargers have a desulphator function that kicks in and runs automatically. These batteries have been on them most of their life. I don't think they were in good health when I purchased them new and they got progressively worse over the years.Now-days, I charge and test all new batteries before they are put to work. 15 batteries purchased this year, 4 sent back as defective and 3 more took a week of charging to hit "as new" specs, not a great strike rate. I was very tempted to kick the voltage up with the welder, to "show em who's boss" a couple of times, but I am testing the charger, not the batteries. It has to go back into a rather large off-grid system, to power a 12 volt emergency backup supply and it's not going to get a lot of tender lovin care. I am really staggered at the amount of sulphate that has gone back into solution, anything smaller than 8 to 10 mm wide on top of the plates has completely gone. I am wondering why it has been so dramatic? the things that are different from what I have done in the past,
Happy Easter I'm confused, no wait... maybe I'm not... |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Dave I haven't had much luck with peak voltage readings as an indicator as to condition as I believe for this to work it needs a high current square wave charger to get enough current to read the plateau voltage, which in turn comes down as the battery accepts more charge for a given current, seems to work best at about 10% of battery AH rated capacity. I put mine through the mill as described earlier and then let stand overnight to read voltage if they dont read over 12.5 volts on a 12 v battery after four cycles it indicates a dead cell, that is on a sealed battery of course, on intervidual cells it is a bit easier as you can check each one. There is a battery tester based on this design available, but I found it only works on smaller batteries under 100 AH as it dosent pulse enough energy to work on higher capacity. All the best Bob Foolin Around |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Yahoo2 Sounds like a good charger you have got there, I have played with batteries for years started by servicing the 32 volt farm systems in the late 60's and early 70's and found that a good desulphator is essential, the ones I use now are Infinitum type as mentioned earlier in the post, I have found them the most effective of the ones I have tried. My early desulphator was a battery charger with a vibrator circuit superimposed on the charge current, a 20K htz high energy device like the old pilot arc welder. The combination ones I have tried do not have enough energy to break down a badly sulphated cell but these little ones do and I leave them on all the time to keep the batteries conditioned. Time will tell how effective they are but so far they have revived my bank to full capacity from less than 30% when I got them, second hand time expired from a government UPS safety lighting system. I have found with lead acid batteries badly sulphated to sit them at 27.5 to 28 volts works the best as if you go to a higher voltage the gassing interferes with the desulfation process, as the bubbles formed on the plates insulate the surface area in the immediate area. For equalization I use a desulphator across a battery with lower voltage until it equalizes. On sealed 12 volt batteries thats about all you can do. Also boiling the battery to equalize tends to remove active material off the plates and end up as sludge in the bottom, and cannot be reconverted to acid. The electric welder is a Inverter type with nice spiky DC and it breaks through batteries that all else fails on, I also use a Lincoln DC welder on stubborn ones but it is inclined to blow them up if they have internal shorts, so I wouldn't recommend that for normal use. For load testing I use a 12 volt starter motor fitted with a disk brake and a volt meter and 300 amp meter, it gives a good load test. I haven't had much luck with conventional cycling to 50 - 60% discharge, I found that it reduced capacity to a degree, it was better to float and desulphate during the rescue as it will get that cycling later. Once they go through the color change you mention and the electrolyte goes clear that is the time for testing. Most battery charges use a bridge rectifier and the voltage isn't spiky enough to help desulphation, same applies to car alternators thats why the older batteries with a generator lasted longer I think. Also solar is hard on batteries as it lacks spikes on the charge current. All the best Bob Foolin Around |
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WindyMiller Regular Member  Joined: 05/04/2011 Location: United StatesPosts: 62 |
GidDay! I want to first off say I am new to the forums and new to the alternative power scene. So if I ask what seems to most as silly questions? I am trully sorry for that! I am only trying to learn as much as I can about all this stuff and hopfully have a little fun in the process!  I am currently working on my first wind turbine project which involves converting a Dayton 3/4 HP, 9 lead, 3 Phase motor (I live in the USA)into a permanent magnet alternator which I will be rectifying and charging 12 Volt batteries. My question is I have a deep cycle marine battery that does not have much use on it that I was using with a 750 watt inverter for emergency power failures. The problem is I stupidly left it without recharging after running my computer on it for about 10 minutes. (This is what happens when you get distracted by other things!) So the next time I go to use it a few months later it is completely flat. 0 volts! Oh great know what do I do? So I hooked it up to my small petrol generator to see if I could recover it? Well after charging and draining (dropping a steel bar across the post)for the better part of a day it seems to sit at about 10.5 Volts. My question is? Does anyone think it is possible to salvage this one? I payed about $80 dollars for it when it was new and I really feel silly for possibly destroying it!  It really has not been used hardly ever. Yes it has been negelected by me because my system is really inadquate for maintaing batteries. This is why I am now putting up a wind turbine. So I am wondering if anyone has any advice or links to a desulfater I could build and try or any other suggestions?
Has anyone ever tried any of the suggestions or ideas on these sites by chance? http://blog.hasslberger.com/2007/01/how_to_convert_a_lead_ac id_bat.html http://ysuusy.com/Lead_Acid_Car_Battery_Repair.html http://www.batterydoctors.com/tech.html http://members.optusnet.com.au/~weza/ReBuildingBatteries.htm Has anyone ever had any luck with the EDA or China depot chemicals? Ya or ney? http://www.diyelectriccar.com/forums/showthread.php?s=9231d6 360d46aeff1fc79c0ff0839808&t=30603 http://www.goodideacreative.com/battery_bg_contents.html www.powerstream.com/1922/battery_1922_WITTE/batteryfiles/cha pt... Robert |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Windy I use a infinitum desulphator to great advantage but it isn't a miracle worker. www.infinitumstore.com Its not a good idea to short out the battery to cycle it, I have found that when a battery is as bad as yours it is better to leave it in trickle charge with the desulphator connected for at least a week, then let it sit overnight and test voltage, if it wont hold over 12 volts, do it again for another week, if it still drops to 10 volts then it has a dead cell. Remember it has taken months for the sulphate to form and it won't dissolve in a few days. I have had batteries at 0 volts recover but only after 3 months on the desulphator. When it has revived to a decent level then some shallow cycling no more than 50% with a heavy load can help, but to discharge the battery fully only starts the sulphation process again. There are many different opinions on the net as to how is best to do this, but all I can say is it works for me, but if you are going to count your time it is cheaper to buy a new battery and look after it properly next time. Even the so called deep cycle batteries sold now will die quickly if regularly discharged below 50%. In the old days we had huge 2 volt cells that where made to be discharged to 80% but they had enough lead in them o make a cannon ball not like the new ones now. When discharged to that level they required recharging right away not to be left for any period of time at a low charge level, as the sulphate starts to form a insulating crystalline layer on the plate reducing the conductance of the plate a bit like resistance in series, this reduces the active area of the plate resulting in lower AH capacity and as time progresses it blocks conduction altogether, thats what sulphation is. Good luck with your battery. All the best Bob PS: Chemical additives are a waste of money in my opinion as they alter the chemistry of the battery to give it a short boost in performance but longer term degrade the electrolyte. Foolin Around |
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| WindyMiller Regular Member Joined: 05/04/2011 Location: United StatesPosts: 62 |
HI VK4AYQ I will give the sulfator a try and see what happens? I will post my results as time allows. Thankyou for your response, It is much appreciated! Robert |
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mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
VK4AYQ, As I mentioned in another post, I have 2 large 12 volt starting batteries out of the bulldozer...1000 cc amp each, and now have them on the new desulphurnator. I've been alternateing them every 4 hours, one on my 12 volt charger, while the other is on the desulphurnator, then switching. I can already see the fluid is much clearer and the tops of the plates as well, My question is...should I give these a rest for a day and then test the batteries? They are both warmed up to about 90 degrees F. (30 degrees above ambient). All cells are gasing nicely, and the charger indicates that they are each nearly fully charged. I've never did this/done that, so sorry if this is a silly question. I forgot to mention, they have been on the charge cycle for a total of 8 hours and on the desulphornator a total of 8 hours, (each). Thanks in advance, .....Mac46 I'm just a farmer |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi mac Sounds like they are responding good, what I would suggest is connecting them in parallel on the charge to reduce gassing and leave the desulphator on them as well for 24 to 48 hours then separate and let sit for 12 hours, then measure the voltage both should be the same within .2 volts of each other and be 12.5 or above. if one is much lower it could need more time on the desulphator. Try not to let them gas to much as it takes the active material off the plates as sludge instead of re-converting to active material. It is a slow process to turn the sulphate back to acid so the longer you can keep them on float, 3 to 5 amps with the desulphator hooked up the better. If you stop to soon you will still have sulphate and the batteries will continue to have low capacity and die. Remember that it took a few months for them to sulphate so do not expect it to go away in a few hours. You can leave the desulphator on them when working them for as long as you like. All the best Bob Foolin Around |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
VK4AYQ, Thank you for you'r advice...common knowledge about batteries is'nt my strong suit, I did go ahead and take them off the charger/desulphornator to let them cool down. I have another deep cycle battery on the desulphinator at this presnt time, it is also responding favorably. I'll hook "like type" batteries up in parallel and put them back on the desulphinator for a time. I don't understand why the stores don't carry these desulphinator's, could'nt find them in my area any where, had to order it on line. So far so good, I'm impressed with it, glad I have it. I think this is part of the learning curve of haveing a wind generator. .....Mac46 I'm just a farmer |
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| yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Hi Mac, you haven't given us a lot of information to work with but I will have a go. 1000 cold cranking amps doesn't tell me how big the battery is, this is its ability to run a starter motor. i would guess that they would be between 115 and 160 Amp hour batteries (if they are caterpiller ones). If the battery is in good condition and you left a light on and drained them and recharged straight away, you are probably looking at about 20 hours with an average 10 Amp charger to get them up to better than 90% charged. If you are looking to rejuvenate some tired batteries then its a different story. A badly sulphated battery needs time and gentle charging to dissolve the hard crusty sulphate into sulphuric acid, it will look like it is fully charged but the total capacity may be down to 30 or 40 Amp hours.If you check it with a hydrometer,after charging, there will still be a lot of water in the cells instead of nice heavy acid. Does your charger have a float or trickle charge stage? This is where the bulk charging is complete and the voltage is reduced to between 13.2 and 13.8 volts (depending on the charger). Desulphators work their magic best at this point, if your charger doesnt have this function get a small one that does. Hook the little charger up after the big one has charged the batteries. This is what I would do. Hook the two batteries together as a 12 volt bank (+ to +,- to -) charge them as a pair, in fact the more the merrier, hook your desulphator to one battery while they are charging and leave it on for at least a couple of days then switch it to the next one.I would leave them like this for at least a couple of weeks and rotate the desulphating gadget. Word of caution: some larger chargers (7 Amps and over) don't have the brains to reduce the charging amps enough to float charge smaller batteries for long periods (more than a month) without the batteries loosing large amounts of electrolyte. A good quality 3 amp charger is plenty big enough to float anything up to 600 Amps. Hope this is a help. P.S. Temp should be fine under 113 F. I'm confused, no wait... maybe I'm not... |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Yahoo2, Thank you for helping me, I knew not to let them get hot, but did'nt have a clue about how hot. The batteries in question are about twice the size of a regular truck battery, they are a set of twins, and are just 6 years old. Never gave me a problem until I found that they had discharged over winter. One of them seemed to charge back up in less than 24 hours, the second one took nearly 48 hours. I have them paralled together with the desulphinator right now and will monitor them for at least 2 days then check the cell gravity. Thanks for all the info on chargers also, I'll need to get a quality trickle charger. I'm finding out all kinds of info about batteries, "I had no clue". All I knew to this point was keep them clean, connections tight, proper fluid levels, and keep them fully charged. Fully charged to me was when the big charger dropped below 10 amps, Sounds like this is the point where the real chargeing begins...with the trickel charger, and some time to let things soak up and top off. Also sounds like I'm about 1 year late in getting a desulphinator. Thanks again for all the info. .....Mac46 I'm just a farmer |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Everyone, Strange things these lead acid batteries, seem to have a personality different form each other. I may have brought back one of the two bulldozer batteries from extinction, and the second one is showing some vavorable response. 
Here is a picture of the batteries infront of one of my work benches. This is'nt all of them, I still have some in equipment yet, most of the batteries in the picture are old ones, not able to be used any more. The desulphinator is bringing them back to life again. I'm gaining knowledge and faith in restoreing old batteries to usefulness. VK4AYQ, and Yahoo2, thanks for the advice and tips. .....Mac46 I'm just a farmer |
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