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Resurrecting a battery

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raymondj(at)frontiernet.n
Guest

Posted: Thu Sep 27, 2012 4:11 pm Post subject: Resurrecting a battery

Greetings list,



I have a couple of dead batteries.  Not discharged but killed. They show 

only approx 10.5-11 volts when taken off the charger.  Ron was 

discussing his experience with putting 15V at .5 amps on some batteries 

and resurrecting them to some degree.   I have a bench supply that I 

could set at 15 V and .5 amps.   My question is whether it will likely 

damage the bench supply to hook it to a battery.  My limited knowledge 

says that it shouldn't make any difference to the power supply what is 

hooked to it as long as it doesn't feed electrons to the supply.



I've got nothing to loose as far as the batteries are concerned, but I'd 

hate to cook my bench supply.  It's an old Heathkit IP-28 and says 30V 

and 1amp so it shouldn't tax the supply too hard.



Just checking with the experts so I don't kill my power supply.



Thanks



-- 

Raymond Julian

Kettle River, MN.



"And you know that I could have me a million more friends,

and all I'd have to lose is my point of view." - John Prine

rparigoris

Joined: 24 Nov 2009
Posts: 808

Posted: Thu Sep 27, 2012 6:05 pm Post subject: Resurrecting a battery

Hi Ray 

 	How many aH battery are they? 

 	If close to 12 to 18aH aqnd AGM, the good bet would be to try and use the 500mA transformers and circuit board I sent along with the batteries I offered. They limit current to ~ 500mA and the control board will turn off once they reach ~ 15.4 volts. I would try a few cycles where you bring down the batteries to ~ 12.4 volts. It may take several days to get the control board to turn off, especially the first time. 

 	If you have an adjustable power supply, set it to constant current ~ 350 to 500mAs and monitor the voltage. This is not going to be a very fast process, it may take days to get to 15 volts. Once you get to 15.4 volts, let it dwell there for 2 hours at least. 

 	I Please report back if you were able to revive. 

 	I did this with AGM batteries, if you have a  flooded cell battery, you don't have much to lose, but listen carefully and decrease current if things get too bubbly. I tried putting two of the 500mA chargers in parallel on the 12ah batteries and didn't like the noises too much when the voltage got to the upper 14s on some of the batteries. Using only one 5600mA charger kept things happy. 

 	I have a sneaky suspicion that when I took two of the bad batteries I had, after they reached the 15.4 volts and the controller turned off and put them in parallel on just one 500mA charger and let them reach 15.4 volts (which took a long time) it may have helped a little, the first time anyway. I didn't run a capacity test, but the voltage seemed to hold up better after I let the batteries sit for several days. 

 	Ron Parigoris    [quote][b]

raymondj(at)frontiernet.n
Guest

Posted: Thu Sep 27, 2012 6:44 pm Post subject: Resurrecting a battery

Ron, these are flooded cell auto batteries.  One I think is a 

deep-cycle.  I put one of your transformers across the terminals and "It 

don't work no more". That is what leads me to worry about the power supply.



I don't think that the power supplies I have are constant current.  I 

think the current setting is a max allowable setting, but I'm not sure.



By the way. I'm getting good use out of those batteries.  Thanks again 

for offering them here, even though it was more headache for you.



Raymond Julian

Kettle River, MN.



"And you know that I could have me a million more friends,

and all I'd have to lose is my point of view." - John Prine



On 09/27/2012 09:01 PM, rparigor(at)suffolk.lib.ny.us wrote:

 	  Quote: 	
		  

 Hi Ray



 How many aH battery are they?



 If close to 12 to 18aH aqnd AGM, the good bet would be to try and use 

 the 500mA transformers and circuit board I sent along with the 

 batteries I offered. They limit current to ~ 500mA and the control 

 board will turn off once they reach ~ 15.4 volts. I would try a few 

 cycles where you bring down the batteries to ~ 12.4 volts. It may take 

 several days to get the control board to turn off, especially the 

 first time.



 If you have an adjustable power supply, set it to constant current ~ 

 350 to 500mAs and monitor the voltage. This is not going to be a very 

 fast process, it may take days to get to 15 volts. Once you get to 

 15.4 volts, let it dwell there for 2 hours at least.



 I Please report back if you were able to revive.



 I did this with AGM batteries, if you have a  flooded cell battery, 

 you don't have much to lose, but listen carefully and decrease current 

 if things get too bubbly. I tried putting two of the 500mA chargers in 

 parallel on the 12ah batteries and didn't like the noises too much 

 when the voltage got to the upper 14s on some of the batteries. Using 

 only one 5600mA charger kept things happy.



 I have a sneaky suspicion that when I took two of the bad batteries I 

 had, after they reached the 15.4 volts and the controller turned off 

 and put them in parallel on just one 500mA charger and let them reach 

 15.4 volts (which took a long time) it may have helped a little, the 

 first time anyway. I didn't run a capacity test, but the voltage 

 seemed to hold up better after I let the batteries sit for several days.



 Ron Parigoris



 *

 *

rparigoris

Joined: 24 Nov 2009
Posts: 808

Posted: Thu Sep 27, 2012 10:24 pm Post subject: Resurrecting a battery

Hi Ray 

 	You mention that the transformer no longer works after you put it across the battery. Was that with the circuit board connected to the transformer? All you need to do is connect the board in reverse to the battery for a split second and it fries the board. If that's the case, I would say there is a good chance the transformer is still good. You can connect the transformer directly to the battery without the board. Just to make sure, connect a volt meter to the transformer to see it's working and you get the polarity correct, if you have a meter that can measure current, make sure you are pumping in 500m As or there about. You will need to monitor the voltage, once you get to ~15.4, let it go for another two hours. 

 	How many amp hours are the batteries? If they are 35aHs, put two of the 500mA transformers on them in parallel. 

 	Ron Parigoris    [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Sep 28, 2012 10:13 am Post subject: Resurrecting a battery

At 07:09 PM 9/27/2012, you wrote:




Greetings list,



I have a couple of dead batteries.  Not discharged but killed. They 

show only approx 10.5-11 volts when taken off the charger.  Ron was 

discussing his experience with putting 15V at .5 amps on some 

batteries and resurrecting them to some degree.   I have a bench 

supply that I could set at 15 V and .5 amps.   My question is whether 

it will likely damage the bench supply to hook it to a battery.  My 

limited knowledge says that it shouldn't make any difference to the 

power supply what is hooked to it as long as it doesn't feed 

electrons to the supply.



  Correct. Charging batteries with a bench supply is not without

  some risk . . . depending on the design of the supply. I was

  charging a 24 v battery with a big HP 40A supply when the power

  went off. The HP's crowbar ov protection circuitry lost its reference

  voltage and triggered. Unfortunately the crowbar system assumed

  that the energy to be stood-off was coming from AC mains, not

  from the load. Hence, the fuse was on the wrong side of the

  crowbar and I burned some circuitry. I now charge batteries

  through a fuse.



  I'm not aware of any specific instances of potential hazard

  to small bench supplies . . . I suspect it's very low.



I've got nothing to loose as far as the batteries are concerned, but 

I'd hate to cook my bench supply.  It's an old Heathkit IP-28 and 

says 30V and 1amp so it shouldn't tax the supply too hard.

   A brief look-see at the IP-28 schematic



http://tinyurl.com/ydhkrky



  reveals no sneak paths that might make the supply vulnerable

  to battery back-feed.



Just checking with the experts so I don't kill my power supply.



   No biggie . . . but since you're not depending on the

   supply for anything but boosting . . . don't really need

   accurate regulation . . . putting a diode in series

   with the supply totally eliminates any risk.



   Now, probability for successful recovery with ANY supply

   is problematic. The OVERVOLTAGE boost technique described

   in Concorde literature and elsewhere is designed to stir

   up chemistry that refuses to accept a charge at standard

   voltage levels.



   You can put a 100w light bulb in series with a diode

   bridge rectifier and use this as a current limited source of

   high voltage to hook to your battery(ies). Watch the voltage across

   the battery. If the chemistry is coming awake, the voltage

   should begin to drop and ultimately level off at normal

   levels expected for a 1 amp constant current charge.



   If the voltage doesn't show signs of dropping, the

   chemistry isn't asleep but dead. By the way, the ol'

   light-bulbs and rectifier ploy has an ancient history going

   back to selenium rectifier days.



   The rectifier need not be rated at any voltage greater

   than terminal voltage for the battery. Charging current

   is controlled by how many/big the light bulbs are.

   I once built a battery charger with 4 bulb sockets on

   a board along with a selenium bridge rectifier. With

   200, 200, 100, and 50 watt bulbs in the sockets, I could

   set charge rate between .5 and 5.5 amps by seating/unseating

   the lamps in their sockets.



   Of course, this is NOT regulated so you have to watch

   terminal voltage and shut the critter off when charge

   is complete. Left unattended it will boil off a battery.



   Bob . . .

raymondj(at)frontiernet.n
Guest

Posted: Fri Sep 28, 2012 12:46 pm Post subject: Resurrecting a battery

I had just taken a battery charger off       the battery and used just the transformer, with correct polarity.        

       

       They don't give an amp/hr rating but it is 675 cold cranking       amps.  It's a marine starting/deep cycle battery.

        	  Quote: 	
		  Raymond Julian

Kettle River, MN.



"And you know that I could have me a million more friends,

and all I'd have to lose is my point of view." - John Prine 	
       On 09/28/2012 01:21 AM, rparigor(at)suffolk.lib.ny.us (rparigor(at)suffolk.lib.ny.us) wrote:

     

     [quote]       

 Hi Ray       

 You mention that the transformer no longer works after you put         it across         the battery. Was that with the circuit board connected to the         transformer? All you need to do is connect the board in reverse         to the         battery for a split second and it fries the board. If that's the         case, I would say there is a good chance the transformer is         still good.         You can connect the transformer directly to the battery without         the         board. Just to make sure, connect a volt meter to the         transformer to see         it's working and you get the polarity correct, if you have a         meter         that can measure current, make sure you are pumping in 500m As         or there         about. You will need to monitor the voltage, once you get to         ~15.4, let         it go for another two hours.       

 How many amp hours are the batteries? If they are 35aHs, put         two of the         500mA transformers on them in parallel.       

 Ron Parigoris        	  Quote: 	
		  

	
     [b]

raymondj(at)frontiernet.n
Guest

Posted: Fri Sep 28, 2012 1:43 pm Post subject: Resurrecting a battery

On 09/28/2012 01:12 PM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   You can put a 100w light bulb in series with a diode

 bridge rectifier and use this as a current limited source of

 high voltage to hook to your battery(ies). Watch the voltage across

 the battery. If the chemistry is coming awake, the voltage

 should begin to drop and ultimately level off at normal

 levels expected for a 1 amp constant current charge.

Here's where my ignorance starts showing. Is this setup using mains 
	


voltage? Rectified and current limited? 120+ volts DC, current limited 

to 1-2 amps?



Raymond Julian

Kettle River, MN.



"And you know that I could have me a million more friends,

and all I'd have to lose is my point of view." - John Prine

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Sep 28, 2012 6:36 pm Post subject: Resurrecting a battery

 	  Quote: 	
		  Here's where my ignorance starts showing. Is this setup using mains voltage? Rectified and current limited? 120+ volts DC, current limited to 1-2 amps? 	


   Yes. Suppose the power coming into the back of your

   house was being supplied by one of the honorable

   T.A. Edison power stations . . . 120 volts DC.



   Okay, 150 watt bulb will draw about 1.30 amps.

   

   Now hook a 12v battery in series with this setup

   such that current flowing through the lamp tends

   to CHARGE the battery. Voltage across the

   lamp drops by 12v or so the current drops a bit.

   But the lamp still burns brightly and current

   through the lamp is charging the battery . . . the

   lamp becomes a 100W resistor.



 [img]cid:.0[/img]



   Horribly inefficient?



   Yes . . . unless you want to sit down and read a book

   while the battery is charging and can make use of

   the light output.



   Now, consider a similar design goal but the power

   delivered to the back of the house is AC. We can

   add the rectifier such that reversal in the applied

   voltage is rectified so that it always charges the

   battery irrespective of line polarity . . . the lamp(s)

   still limits the current . . . want a stronger charge

   rate? More or bigger lamps.



 [img]cid:.1[/img]



   Again, only 10% of total energy consumed goes into

   the battery . . . but it IS current limited. Probably

   not a charger you want to build for routine battery

   maintenance but it is an option for generating a

   current limited VOLTAGE source that will RISE to what ever

   level the injured battery will accept. If it goes to more

   than 2X battery rating and/or if it doesn't begin to

   fall in a few minutes, then this resuscitation gambit

   is futile and should be discontinued.



 

 

   Bob . . .

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raymondj(at)frontiernet.n
Guest

Posted: Fri Sep 28, 2012 7:07 pm Post subject: Resurrecting a battery

raymondj(at)frontiernet.n
Guest

Posted: Fri Sep 28, 2012 8:46 pm Post subject: Resurrecting a battery

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Sep 29, 2012 8:51 am Post subject: Resurrecting a battery

At 12:34 AM 9/29/2012, you wrote:

  	  Quote: 	
		  Very clear now. 1 picture=1k words.  I had the lamp on the DC side in my mind.  I'll report back when I have something to report.



 I assume there is no reason to put in a cap to try to limit ripple. 	


  Naw . . . those molecules of lead and acid aren't picky.

  There's some school of thought that impressing clumped

  up molecules with bursts of high frequency energy tends

  to break them up and increase surface area . . . i.e.

  restore active chemistry. This prompted a constellation of

  product development in 'battery de-sulfators'.



  http://tinyurl.com/9c4gwk8



  I've yet to see a well crafted laboratory study that confirms

  any claimed efficacy for such devices. 



  Actually, about 1965 there was a rash of articles in

  popular 'technical' publications suggesting that one

  could recharge the carbon-zinc cell if the energy replacement

  profile was half-wave rectified DC (Figure 2 with only

  one diode). This 'rattling' of the chemistry was suppose

  to make things happen that the original designers of

  the carbon-zinc cell never imagined.



  I'll forward a copy of the previous post to Skip Koss along

  with this one . . . he may have additional insights to

  contribute.



 

   Bob . . .    [quote][b]

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