Life after sulfation.Used batteries

Hello !. I just had to post these results I'm getting with some used batteries. Like some other people , I'm not too well heeled so I look for ways to cut system cost. One of those ways is to desulfate used batteries. I work at a school where we have floor machines that use 6 volt deep cycle batteries. The people there don't give the batteries much care (none).The chargers are bulk chargers and don't equalize or float and the machines sit idle alot with no charger on the batteries. They sometimes don't get recharged until the machine won't go. Sometimes they aren't even used for a long time and just sit and self discharge.
We recently replaced the batteries in three machines ,one had been used heavily and the batteries were cycled daily for five years.Those batteries were 12 v trojans and I think their life was close to being over. The other two machines had 4- 6 v trojan 305 ah and had been sitting with an occasional charge but I knew they were sulfated and had most of the plates left.Perfect for my system I took them home and began checking the cells. I found two cells in each pack that would not even read on the hydrometer. Others were reading in the high discharged range ,about the same. I got some EDTA and put a teaspoonful in each bad cell and wired them for 24 volt.
Using the charger in my gtfx2524 and mate I did long bulk charge at 29.6 v and then gave them a couple of nice long equalizing charges at 31v. Then I checked the SG again. No change. I then programmed the Mate to cycle the batteries using HBX. I pulled them down to 24.6 and back to 29.6 with the charger every 12 minutes all day long. That was yesterday , I checked the SG again and its coming up. One cell that read nothing before now reads the same as the others. Still low but I'm getting very good results so far.Giving these batteries the voltages they need is bringing them back to life. I'm thinking the Outback inverter chargers are very good battery conditioners at this point. Just had to share.
Thanks
Chuck

Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Life after sulfation.Used batteries

    i'm sure you will find that although you will get something from them, it won't be as much or not for very long. their days are numbered, but may suffice for now. if it's old batteries you're looking for go find a cell phone company and see if they'll be willing to part with their agms when they cycle out the old ones. they replace them every so many years or months depending on circumstances. they are excellant batteries, but due to slight age or other circumstances they deem them to be unreliable.
  • System2
    System2 Posts: 6,290 admin
    Re: Life after sulfation.Used batteries

    Here is a link that gives a lot of good info on Lead Acid Battery Desulfation: http://www.shaka.com/~kalepa/desulf.htm , They have a BBS for questions. And a Home Power link to issue 77: http://www.homepower.com/files/desulfator.pdf . One of the home brew things that lets you build your own.
  • System2
    System2 Posts: 6,290 admin
    Re: Life after sulfation.Used batteries

    I had four 400AH Rolls/surretes w/ low SG approx 25%, and one dead automotive deep cycle battery with a shorted cell.
    All are rgistering 100% SG now and holding a good charge.
    Sulphated cells were visible on all batteries.
    For the rolls I charged them with an IOTA DLS55/IQ4 and during and after charge I would beat on the battery with a rubber hammer. This, I believe, was the key to reconditioning the batterries. I did put some EDTA in the Rolls and I did temporarily put an electronic desulfator on but did not notice any change as a result of those actions.
    For the automotive deep cycle I beat on it and rinsed it with garden hose several times dislodging lots of gunk (sulphate percipitate?) Then I put new electrolyte (sulphuric acid) in and charged and beat and charged and beat about 6 cycles. Last check the specific gravity was very close to 100%.
    Granted this is not a scientific result, but for me I'am now happy with all of my battery's condition and performance.
    Mark
  • System2
    System2 Posts: 6,290 admin
    Re: Life after sulfation.Used batteries

    interesting, ive heard brock say the thing about doing the battery shake now and then, ive since gotten in the habit myself. no rubber hammer though (yet, muahahhahaha)
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Life after sulfation.Used batteries

    i suppose the light taps or shakes could help with minor sulphation, but i'm not sure if you'd want to or should keep it up for very long. batteries are heavy and can get weak spots to develope on the casing due to impacts. i know when my wally world specials developed some sulphation, nothing got rid of it or helped as i used my radio equipment, light taps, and a few shakes and it didn't do a thing for them. desulphators are low powered radio transmitters so i put on high power to it and nothing happened. those batteries weren't for this world very much longer after the sulphation occured even though i did go farther than most people would. i did not put that edta or whatever that stuff is into them as the only thing i put in was distilled water and a bit of the sulphuric acid at one point as the sg indicated enough of it had been boiled away to warrant some more to be added. so far i'm not impressed with any method of getting rid of sulphation.