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Author Topic: Batteries and desulfators - I needs ta know!!  (Read 4625 times)
Chaz
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« on: December 29, 2011, 06:12:45 AM »

Hey folks,
Back to the age old issues with batteries...... MAN, these things drive me nuts!! And it seems I am always having to buy new ones. (well, I do have a lot Roll Eyes) I just had to put a new gell cell in my daily driver -'56 Chevy. (love that car!  Grin)
Anyway, I really want to know if desulfators work - which I "believe" they do - but, I just don't know. And, if in fact they do, I have also heard that they are not all created equal. Which one(s) the best as far as your personal experience or proven knowledge goes?
My issue now is my start batteries. They don't seem to hold a charge. I replaced them a couple years ago. I had DD's and went to 31's. Now, I did commit the cardinal sin of letting them discharge all the way (a couple times  Embarrassed) because for some reason the high dollar equalizer switching device (Heart Interface Pathmaker, 200 amp) seems to not be "all that and a bag of chips"!!! I know I have a small drain on the starts (I would love, love, LOVE to have the wires stripped out completely and only the absolute nessecary ones left. Oh well....... one can dream...) but thought I could live with that by putting on the Pathmaker and just deal with it. My bad.
So anyway, I'd love to hear what you guys know about those little "wonder box's".
Thanx a bunch!!!!

Chaz
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« Reply #1 on: December 29, 2011, 06:35:46 AM »

In normal circumstances (ie. in a regularly-used vehicle), start batteries don't die because of sulphation - in fact the duty-cycle of a start battery (high current draw, immediately followed by a high charging rate), is a very good way of avoiding sulphation, and perhaps even re-dissolving any sulphate that has formed.

But if the bus has stood for lengthy periods with the start batteries flat, then, yes, a desulphator might help. I do have one myself, and believe in the principle, but don't have enough practical experience of their effectiveness to give advice. I have also read that controlled over-charging (ie. boiling) is as effective a way as any to desulphate a battery, and perhaps a better approach than leaving a proprietary device connected to it for days or weeks.

Jeremy
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« Reply #2 on: December 29, 2011, 10:48:32 AM »

I recently bought two and have them on my 8D's now.  After that, I will put them on my house bank.  Since the manufacturer said it would take about 4 weeks to do the job, I will let you know if I can detect a change in a month or so.  My house bank is 3 AGM batteries that used to sit at around 13v.  They now sit at about 12.6 or 12.7.  My thought is that if the sitting voltage can be raised, the desulfators did something good.  Unfortunately, this is just my speculation.
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« Reply #3 on: December 30, 2011, 09:08:32 AM »

I researched desulphators for a long time and finally settled on three different brands... bought them, tried them and decided that they were all a total waste of money.
They didn't do squat to the batteries but they did put some of my hard earned bucks into someone elses' pockets for nothing!

I did find a process that actually works and works well, as mentioned above by Jeremy... basically you acquire a power supply usually used in the electronics industry that can put out a constant current instead of a voltage, and use it to "overcharge" your battery on purpose.  The power supply is set up to deliver 5 amps to the battery regardless of it's voltage, and once it appears to be fully charged, you continue the process for another 24 to 48 hours.

This results in a battery that will get hot, bubble like mad, eat water constantly, and be very dangerous during that time because it is not only emitting a lot of hydrogen; it is emitting exactly the correct ratio of hydrogen and oxygen that likes to explode with very little provocation.

The results: one set of three Trojan J-185's that were totally dead and sulphated came back to life as if they were almost new.

The second set didn't fare so well- they came bcak to life perfectly as did the first set, but at the very end, about an hour before I was going to turn the process off, something made a spark... the explosions, the fire, and the photos below were the unhappy result...$1000 of batteries totally destroyed and an awesome toxic mess to clean up....




Bottom line: If you're set up safely (Fortunately I did this in a non-flammable concrete block area with a tapered floor that I made specifically for this kind of accident) it works.  But it's not a process for the timid.

A MUCH better option is to use a charger that takes good care of your batteries, keep them watered, and you'll have amazing results for a long time.  I routinely get 6-8 years out of a set of T-105's because I use a good charger that has three stages and an automatic equalization function (my favorite brand is intelipower), and I keep them watered....

EVEN BETTER is to just dump the wet batteries altogether and go AGM.  I finally did this after babying T-105's for all those years, and the whole issue of battery maintainance instantly became invisible to me.
Installing the bank of AGM's eliminated ALL issues, I never think about them ever, and they just work....
« Last Edit: December 30, 2011, 09:23:09 AM by boogiethecat » Logged

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« Reply #4 on: December 30, 2011, 09:58:50 AM »

... basically you acquire a power supply usually used in the electronics industry that can put out a constant current instead of a voltage, and use it to "overcharge" your battery on purpose.  The power supply is set up to deliver 5 amps to the battery regardless of it's voltage....

Interesting - I'd always assumed a basic old-style battery charger would be all that was required; with a dumb transformer-type charger, once the battery was fully charged the voltage, and therefore current, would be more-or-less constant wouldn't it? Or is there more to it than that?

This isn't just an academic interest as I have a matched set of three nicely-sulphated batteries waiting to be dealt with. The safely advice is well received - performing the operation outdoors and preferably with an airflow blowing across the batteries would seem a minimum precaution?

Jeremy
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« Reply #5 on: December 30, 2011, 10:03:20 AM »

Chaz:

In case you missed it, here is my thread about this subject.

http://www.busconversions.com/bbs/index.php?topic=22462.msg246862#msg246862

Also, consider investing in a battery switch that totally disconnects your batteries from the bus when your vehicle is stored. I purchased the large battery cutoff switch at the local Camping World. (I think it was around $23.00.) Buses are famous for coming up with "phantom loads" that will kill your battery, even when you think everything is off.  

Camping World has two versions of this switch: One says "House battery" and the other is "Chassis battery". The house battery one says "Continuous rating 275 amps; Intermittent rating 455 amps; Cranking rating 1,250 amps". It is rated at 48 Volts, and can be wired with cables as thick as 1/0.

I have added a second one to cut off the engine batteries.
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« Reply #6 on: December 30, 2011, 10:11:15 AM »

The safely advice is well received - performing the operation outdoors and preferably with an airflow blowing across the batteries would seem a minimum precaution?

Jeremy

Usually, they recommend leaving the charged battery on a trickle charge, of 1-2 amps.

Also, if you have air going across the charging batteries, you do NOT want the air to take the explosive fumes towards the charger or another possible flame ignition source.
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« Reply #7 on: December 30, 2011, 10:45:51 AM »


Usually, they recommend leaving the charged battery on a trickle charge, of 1-2 amps.

Also, if you have air going across the charging batteries, you do NOT want the air to take the explosive fumes towards the charger or another possible flame ignition source.

I understand what you're saying...but I think the danger very rapidly diminishes as the explosive gases disperse. I don't rightly know how big the 'danger area' is, but my instinct is that it would be quite small, and I'd be doing this in my garden where I could be quite confident that there were no ignition sources for at least 50 feet in all directions.

I'm not quite sure what you were meaning with the trickle charge comment.

Jeremy
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« Reply #8 on: December 30, 2011, 12:33:16 PM »

Jeremy... "dumb" chargers do put out a constant current, but they are also fixed in the maximum output voltage that they can produce, which usually factory adjusted to somewhere aroung the float voltage of the battery they are charging... the result is that as the battery comes up to charge and it's voltage nears that of the charger's maximum output voltage, the current tapers off eventually to zero or near that.  A constant current lab supply can be set for a max voltage that is much higher than a battery could ever attain, effectively continuing to overcharge it quite aggressively until you turn it off manually...
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« Reply #9 on: December 30, 2011, 12:37:18 PM »

Quote
Also, if you have air going across the charging batteries, you do NOT want the air to take the explosive fumes towards the charger or another possible flame ignition source.

I disagree. Totally.
 A good air flow away from the batteries is ESSENTIAL to carry away and dilute the gasses so they can't detonate.  If there is no flow, just like Fukushima but without all the radiation, it will take  very little to make a BIG boom!!!
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« Reply #10 on: December 30, 2011, 01:12:17 PM »

Jeremy... "dumb" chargers do put out a constant current, but they are also fixed in the maximum output voltage that they can produce, which usually factory adjusted to somewhere aroung the float voltage of the battery they are charging... the result is that as the battery comes up to charge and it's voltage nears that of the charger's maximum output voltage, the current tapers off eventually to zero or near that.  A constant current lab supply can be set for a max voltage that is much higher than a battery could ever attain, effectively continuing to overcharge it quite aggressively until you turn it off manually...

Thanks, thats educational. So I guess I'm hitting Ebay for a laboratory-type variable power supply.

Jeremy
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« Reply #11 on: December 30, 2011, 02:18:25 PM »

i used a black and decker desulphator and it did not work. I was told by a bettery builder that the led comes off the plates making the battery useless.
Chris
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« Reply #12 on: December 30, 2011, 03:30:38 PM »

I too, have a little desulfator, and like other, found it to be pretty much ineffective. Over-charging with a dumb charger seem to work much better with mild sulfates.

The constant current supplies maybe a bit too harsh though, as shown by boogiethecat's results... I have 6 amp dumb charger that puts out 16.5volts open circuit. You only see 6 amps at max voltage delta (dead battery). When the batt is full, it floats around 15.5 volts putting out just under 2 amp.

This keeps my 2 8Ds at a nice mild bubble, without too much gas venting. I do this overnight once a year or so, otherwise the bus is always plugged in maintained at 13V.
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« Reply #13 on: December 30, 2011, 03:32:04 PM »

Ebay, search "bench supply"
Get one that outputs at least 10 volts over your battery voltage, and one that will do 5 amps. You don't want to go much over 5 amps

For example item # 320699271028 is probably a nice choice...
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« Reply #14 on: December 30, 2011, 03:55:12 PM »

If you know how to do it a dc welder works good for a desulfators I have been doing it for years with a welding machine and never blew a battery up yet knock on wood lol

good luck
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« Reply #15 on: December 30, 2011, 03:59:15 PM »

Yeah welders are great- constant current up to about 45 volts or so.  Just don't go too high in current!
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« Reply #16 on: December 30, 2011, 06:03:56 PM »

Of course, the charger itself could be an ignition source.
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« Reply #17 on: January 02, 2012, 07:39:39 AM »

Well shoot........ I was hoping for the magic bullet here.  Sad
I have plenty of welders I could use but...... I believe I will pass. That makes me a little squimish. I think I still might like to take a chance on a desulphator if someone has one that they really feel works. Jerry told me, quite awhile back, that they do work but they are not all created equal. He made his. (I'm not that smart)
I am also of the impression that just keeping them "up" is the single best thing to do but that Heart let me down, as well as both batteries, and may have hurt them. Dang.
I also have the disconnect switch but I had to leave it on for the Heart to work. Now it seems the batteries go down with the switch off.
What's a poor boy to do...................  Roll Eyes

Happy New Year all!!!!
  Chaz
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« Reply #18 on: January 02, 2012, 07:50:28 AM »



Jerry Lieber is a electronics expert if you can get him off politics.

He has made several and gave them to good bus nuts.

He also has the neatest bath tub in his coach. Also has good air conditions and inverter that keeps him cool with a 15 amp plug.

best battery info around just have to talk to him.

uncle ned
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« Reply #19 on: January 03, 2012, 07:40:58 AM »

Yeah, Jerry is an absolute Guru when it comes to electronics!! He has helped me immensely over the years. I just didn't want to bug him more than I need to.
But I didn't know he was all that political. We had never discussed politics.
I may have to give him a call again but I hate to bug him. He lives about 2 hours from me so maybe one day I can drive down and have him look over my coach. I have been to his place in my car.
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« Reply #20 on: January 04, 2012, 02:53:42 PM »

An update on my desulfator tests:

After several weeks, I have removed them from the two 8D's and tested the batteries with a hydrometer.  All cells of one battery test very high.  On the other battery, 5 cells test very high, and one cell, the one that was testing bad before has not really improved and tests at the very top of the bad range.  I might have to replace that battery if I do not find another magic solution.

I have now moved the desulfators to the house AGM bank and will see if there is any noticeable change in the next couple of weeks.
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« Reply #21 on: January 04, 2012, 11:23:38 PM »

A one amp charger used with a desulfater gives me thorough desulfating in about three weeks. We never have to buy batteries because I can get all the good batteries I need out of the scrap pile.

However, if one cell is low, I have never had success. All cells must be free of shorts or leakage, and that is how I pick them out.

When a battery has set for a week or so, all the cells will show the same charge if it is a good candidate.

We have been desulfating batteries for nearly ten years, and I have some that are around twenty years old. I don't have the time to pick out a desulfater now, but I'll try tomorrow if I see another request.

Take care.

Tom Caffrey
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« Reply #22 on: January 05, 2012, 03:33:30 AM »

(snip) I don't have the time to pick out a desulfater now, but I'll try tomorrow if I see another request.   

      I'd sure appreciate it if you'd post the name of your de-sulphator or recommend one that has similar specs to yours.  Thanks,  BH   NC
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« Reply #23 on: January 05, 2012, 06:10:17 AM »

Second that!!  Grin
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« Reply #24 on: January 05, 2012, 09:00:46 AM »

I had trouble with this battery last summer on the same cell.  I had read that shocking it could possibly clear out a short.  I hooked it up to a 36v charger I have.  It blew the charger fuse as soon as it was connected, but did get some shock.  After that, when I put the battery on a charger, the bad cell began bubbling like the rest of them (it did not bubble at all before).  The cell also tested in the good range, and I was a happy busnut/camper.  However, the fact that the same cell has failed again makes the fix rather questionable.  I may try doing it again, but I am a bit concerned about damaging the charger.  Further, it would seem that even if it works for a bit, you could not call it a dependable battery; it could go bad at any time.
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« Reply #25 on: January 05, 2012, 01:22:16 PM »

I just recently had an 8D fail on a trip and by the time I figured it out it proceeded to cause the other one in parallel to fail.

I assume the first failed one was shorted out and caused the second one to fail.

An expensive lesson in batteries.

I replaced them with 4Ds which are less expensive and plenty powerful for engine starters. Easier to handle for an old wimp like me too!!
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« Reply #26 on: January 05, 2012, 05:26:21 PM »

Interesting idea of Lin's... if you hook a smallish 24 or 36 volt charger (for example one that maxes out at 5-8 amps) to a 12 volt battery in need of conditioning (that nasty overcharging process that seems to work really well at desulphating- although it's dangerous 'cause of the gasses generated)
...well, the charger would simply think it was hooked to a discharged battery of it's [higher]rated voltage and thus would continue to charge the 12 volt batt at it's max current forever... until you manually intervene.  It's a good solution to not having to purchase a lab-style supply for this purpose...
 
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« Reply #27 on: January 05, 2012, 06:08:11 PM »

Sooooo, if you have one of these chargers, a person could hook it up outside and plug it into a timer for say 12 hours at a time (??), let it do it's thing and just check the water??
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« Reply #28 on: January 05, 2012, 11:19:36 PM »

Try eBay's item nos. 150438219961 and 280801698658. The Malaysian unit we have has worked well for us and the Battery Minder has  a good reputation. There's even a kit available on eBay from the same part of the world that ought to work.

Good luck.

Tom Caffrey
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« Reply #29 on: January 06, 2012, 09:40:14 AM »

  Someone tell us about the welder trick? Do you tap it a few times or actually make a hard connection and burn it for a bit?? Im always curious about batteries. I have an old Miller DC stick welder if that would work.
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« Reply #30 on: January 06, 2012, 09:56:15 AM »

A DC welder is basically a constant current power supply, so it'd be used the same as the small lab supply, turn it on for 12-24 hours and constantly overcharge the battery. The trick with a welder is that you'd have to be able to turn it down to 5-6 amps.  Many of them can't go that low even on their lowest settings...

And Chaz... yes, that's it! Outside, fireproof (and acid proof) area, well ventilated and NO sparks!!! (I think my adventure was caused by a rat moving a wire that had an alligator clip, causing a spark that way)
You just keep on watering it and charging it, and looking at the specific gravity of the electrolyte.  Eventually it will come up to a normal range for fully charged... that's when you're done... It might take days, and it might not ever happen. But if the battery doesn't have shorted cells, it will work most of the time.
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« Reply #31 on: January 06, 2012, 02:14:01 PM »

  So your putting a much higher voltage into the battery at low amperage?

  I have two Trojans that suddenly died about a year ago, and while they are 7 years old and likely done, I would like to experiment with them a bit.

  Back when I was 20 I scrounged a whole bunch of jusn or dead batteries and tried everything I could read about to bring them back to life. Tried flushing them, putting in new acid, over charging, reverse polarity charging, most never came back enough to make it worthwhile and all I really accomplished was running the electric bill up. I never heard of this de-sulfation thing before other than just using a long slow charge.
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« Reply #32 on: January 06, 2012, 03:15:18 PM »

You probably need to read this thread through from the beginning otherwise you risk doing something dangerous in your 'experimentation'. Boogie gave a good description of the constant-current desulphation process on the first page.

--

In recent replies a few people have mentioned bad cells and shorted-out cells; I'd like to understand exactly what is being talked about here. I can imagine scenarios where the plates in one cell could become shorted-out, for example if a broken-off bit of lead got stuck between them or perhaps excessive current draw had heated the plates until they distorted and touched each other.

Is this the kind of shorting-out people mean? And if it is, how can you tell that it has happened? I'm not sure a hydrometer would tell you that, and you can't test the individual electrical output of a lead acid battery in the way that you can with a Nicad pack for instance.


Jeremy
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« Reply #33 on: January 06, 2012, 05:38:10 PM »

Jeremy,

This is just my understanding which is made up of some fact mixed with rumors.  There can be several reasons a cell shorts out.  One way that I have read about involves debris being accumulating between plates for different reasons and causing a short.  In this particular type of short, some online sources said that you could possibly shock the cell back to life by different methods that would be hoped to melt out the short.  It is obviously a long shot and could be pretty hazardous; especially since you have no way of knowing the real nature of the short you are dealing with.  I even once saw a home built contraption the had an inline fuse that was meant to break as soon as the switch was thrown in the hope of getting an instantaneous melting of the short while cutting out quick enough to avoid a catastrophe.  That is what I was hoping to do last some when I connected 48v to my 12v 8D last summer.  It seemed to work, but now the same cell is bad again.  I tried doing the same thing with 24v this morning.  I only succeeded in burning out both fuses in my charger.

In my experience, a bad cell does show up on the hydrometer.  For example, this battery has 5 cells that are gloriously high and one that is bad.  That bad cell did come back on the hydrometer reading when I shocked it last time.  Apparently, it is possible to get some temporary benefit from this method, but it does not solve the true cause of the problem.   If I charge the battery up now, it seems to lose about 1v per day not connected to anything else.  Another thing I have noticed is that if I open all the cells and put it on a high charger, the good cells will seriously bubble and the bad one does not bubble at all.

You are right in your warnings here.  As Garry's photo suggests, one is really playing with fire here for relatively small savings, but there is no foolishness that is beyond the consideration of anyone that would own a bus.
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« Reply #34 on: January 06, 2012, 05:46:18 PM »

"but there is no foolishness that is beyond the consideration of anyone that would own a bus."

This needs to be the motto for us all.

Merchandising, cups, towels, banners, t-shirts....

Beware, we are dangerous, we own buses.

happy coaching!
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« Reply #35 on: January 06, 2012, 06:34:58 PM »

but there is no foolishness that is beyond the consideration of anyone that would own a bus.

  Probably true for many other hobbies or endeavors as well. I think for most reasonable people, when we have unlimited resources ($$$$$) we just keep buying everything brandy new and toss the waste behind. One the other end of life after some of those unlimited resources vanish, we start figuring out how to maintain with a smaller pile. A few years ago I didnt care, now I do. A few years ago I could have bought what I wanted, now I cant always. Luckily I learned how to scrounge and adapt when I was young and it gives me options I wouldnt have without that knowledge. Like now im much more conservative in what I buy and try to take better care of what I have. One $40 battery is one thing, $800 worth of batteries is something altogether different these days. If we can safely keep them operating there is no harm and we can save some of that unlimited resources we dont have any more.

  I have to say I never took a battery apart, I hate dealing with them enough without screwing around inside of one. I suppose there are different ways they can short internally, but as suggested the primary reason is plate contamination or warpage from excessive heat. In any case once it occurs you have a major problem. I do not believe shorting is equated to having a dead cell. My understanding is a dead cell is one that for various reasons, most likely sulfation, it is not keeping up with the others and falls off.

  A shorted battery are the ones you really need to be careful of. They can overload your charging system and burn it up. They can blow the tops off, literally explode, catch fire, or some combination. A new term of late is thermal runaway. We would all be wise to carry a bolt cutters in our bus, in an emergency it may be the fastest and only way to cut power if your battery bank goes ballistic. 
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« Reply #36 on: January 12, 2012, 01:17:06 PM »

Every battery should have a separate manual cutoff on negative battery cables to avoid just such dangers.

Bolt cutters could provide some interesting fireworks if used on positive cables!!

I just recently lost an 8D starter because its parallel mate shorted out and ruined it before I figured out the problem.
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