8volt fla deep cycle batteries

[mobile_bob]

came across a local source for 8volt flooded lead acid batteries, deep cycle
that were brought in from korea as a second line for use in golf carts.

they weigh in at about 65lbs each and seem to be of good quality.

they are rated at 165amp/hrs and i got a set of 6 of them to put together a 48volt string
for the test lab.

at 60 bucks each i figured why not give them a try, the life expectancy is about 1200 cycles to 50%
DOD which would be great if i get that out of them.

now i get to see how import korean batteries stack up against other batteries made in this hemisphere.

last piece of the puzzle has now come together.

bob g

[Henry W]

Hi Bob,

Is there a web site to look at them?

Henry

[mobile_bob]

i am looking for a web site for them, so far no luck, but i would like to make a report

i went out and put a voltmeter on them, and was very surprised to find them sitting at 20%
SOC,,, that is horrible!

when i picked them up i was told they had been charged properly and the specific gravity
was 1.275... bullshit!

these things never saw a charger, and if they had checked the specific gravity they would have found
the electrolyte to be nearly pure water... wouldn't even tingle my fingers!

i decided to throw a carbon pile on them, they call will deliver 150amps no problem, so maybe, maybe
they can be recovered?  maybe not?  it looks like i have a real project ahead of me reconditioning these cells to get them anywhere near their rated capacity. then who know's how many cycles they are good for.

i am pissed off at both the supplier for obviously lying to me, and at myself for not taking a meter to check the condition of charge myself before i committed to buy them.

lesson learned and let it be a lesson to everyone here,,, don't ever take a suppliers word for anything relating to a battery.... verify the state of charge yourself, and verify the specific gravity of each cell before you commit to buy a battery , especially a set of batteries.

batteries sitting around nearly dead will have the sulfation crystallize and harden, which makes it a very difficult process to convert the sulfation back to acid in the electrolyte.

i think i am most pissed off at myself, i knew better! 
also i will not recommend this supplier to anyone here or elsewhere, however i won't say anything bad about them by name, until i can determine what i have is bad and if they will stand behind the warrantee without a bunch of hoops and bullshit.

not at all happy with this purchase, however i will suck it up and see if they charge up, with the specific gravity coming up to spec (which would indicate that the sulfation did not harden to the point that it was not fully converted back to acid)  if i can't get the specific gravity back to spec, they will hear from me.

darn it all.

bob g

[Jens]

Bob, how are you intending to bring the batteries back ?
The reason I am asking is because I have a couple of 4D batteries that are only a year old and they are below 50% capacity when using normal 3 stage charging. I have looked for a portable charger to do (true) equalization without success. These batteries were also at about 20% SOC when I got them (house bank on a sail boat)
I have not yet purchased a specific gravity tester - is a cheap Canadian Tire unit (or similar) good enough for monitoring batteries or should one buy something better in which case a recommendation would be appreciated.
Sorry if this ends up hijacking your thread .....

[highwater]

bob g,

if this was a corporate outfit
we would flog you with a verbal warning

Randall

[mobile_bob]

believe me i am flogging myself bigtime and will really get flogged trying to get these things recovered

Jens

currently i have them attached to an apc ups, it will charge up to about 54volts, which would normally be adequate to maintain the bank until i was ready to use them, had they been in good shape to start with..
now i am using this to at least get some charge back into them.

my next move and this because i don't have my trigen set back up yet, is to get some sort of system built up that can get the bank up over 60volts to equalize the batteries, and do multiple cycles and equalizations until i can get the specific gravity back up to spec.

if that doesn't get the job done, i will tip over the cells into a vat and drain them, refill them with fresh distilled water and then put 60plus volts on them over time to see if i can further break down the sulfation crystals.  fresh water and higher voltages will over time break down more of the crystals than would otherwise break down in electrolyte.  i may have to add something to the water to get it to conduct
which i hate to do.  as the crystals break down the specific gravity of the water will increase to a point that it will not go any higher... then i will drain the water, flush them and add fresh electrolyte.

the only other alternative i can think of is to just put them on a equlization source and let them sit there cooking for perhaps a week or more, cycling on and off as they get hot, letting them cool and adding water as needed.

it always takes herculean efforts to recover cells (if they can be at all) once they have been allowed to sit
and have the sulfation harden and crystallize.

maybe i will get lucky and they will recharge up and be ok without a huge effort, but if i had to bet, my bet would be this is not the case.

i am not big on the desulphator scheme, mainly because they break the sulfation crystals loose from the plates instead of converting them back to acid... this just adds crap to the bottom of the cells, or causes shorted plates and does nothing to bring the specific gravity back up to where it ought to be.

at this point i think i will do the recharge, see what i have, make an assessment and then call the supplier
and ask to have them swapped out for something useful.

it just seems so unnecessary
especially given they have the knowledge, the equipment, and experience to know better.

bob g

[rcavictim]

Bob,

I must be missing something here.  If these batteries were sold to you as new, why are you fooling around?  Just take 'em back and demand restitution.

[Thob]

Bob, how are you intending to bring the batteries back ?
The reason I am asking is because I have a couple of 4D batteries that are only a year old and they are below 50% capacity when using normal 3 stage charging. I have looked for a portable charger to do (true) equalization without success. These batteries were also at about 20% SOC when I got them (house bank on a sail boat)
I have not yet purchased a specific gravity tester - is a cheap Canadian Tire unit (or similar) good enough for monitoring batteries or should one buy something better in which case a recommendation would be appreciated.
Sorry if this ends up hijacking your thread .....

I'd recommend that you get a hydrometer similar to this:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7001145_0361128149

It is designed for testing batteries, works in the range that is needed, and has a built in thermometer to do the temperature correction, and the components are not destroyed by battery acid.  It's cost is low enough that it doesn't make sense to use anything less.

[Tom Reed]

Bummer about the batteries Bob. But perhaps now is the time to try a desulfator and see for your self how they work. I used a 12v telco agm battery that woiuld not take a charge for 2 months. When a desulfator was added it started taking a charge and after a month was load tested at 90%. I used this battery for 2 years with a PV panel attached in an RV that was lived in and the battery was heavily cycled. It was still going strong when the trailer went away.

This is the one I use on my battery bank: http://www.ebay.com/itm/YAMAHA-CLUB-CAR-GOLF-48V-BATTERY-DESULFATOR-48-VOLT-/220732894456 and I'm not seeing any reduction in performance in the bank since Nov 2007.

[Jens]

I'd recommend that you get a hydrometer similar to this:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7001145_0361128149

It is designed for testing batteries, works in the range that is needed, and has a built in thermometer to do the temperature correction, and the components are not destroyed by battery acid.  It's cost is low enough that it doesn't make sense to use anything less.

Thanks, I will see if I can find it locally at Napa.

[Jens]

This is the one I use on my battery bank: http://www.ebay.com/itm/YAMAHA-CLUB-CAR-GOLF-48V-BATTERY-DESULFATOR-48-VOLT-/220732894456 and I'm not seeing any reduction in performance in the bank since Nov 2007.

Is there anyone else that can confirm that pulse desulfators work ? Do they also equalize or do they just desulfate? Do they run continuous for as long as they are set up ? Does one need to watch it like an equalizer or does it just do it's thing in the background ?

[mobile_bob]

a bit of an update and my take on desulphators

first of all, i misread the charts for 8volt batteries, an 8.0volt reading equates to about a
50% state of charge, rather than nearly depleted. 

it was late, i was tired, and medicated, so i was wrong about them being nearly flat

however it still didn't make sense how they could be at 50% if they were just transferred
to the distributor from the warehouse two days prior, and then presumably fully charged and tested

as near as i can tell it appears they did fully recharge them, then tested their capacity down to 50%
where they found one that did not pass, brought in a replacement and then gave me a call to come pick them up... apparently they did not recharge after the capacity test, thinking i would install them in a golf cart, put it on a charger anyway before heading to the course for 18 holes.

to be fair i never told them they were for a golf cart and they would have no reason to think that i might have another use for the batteries.

anyway, before i freak out i should get  some sleep, which thankfully i was able to do before calling them, it also gave me time to charge the bank and see that they appear to be responding as they should.

so i will retest capacity myself, to about 30% state of charge at the 20 hr rate, just to make sure they are good to go, and to have numbers to put in the log for each cell.

now here is my take on desulphators

i spent many years researching these things, read every double blind test, every independent lab report
and place most weight with sandia labs testing over those tests performed by those that sell them and those that have bought them.

there is no evidence that supports they work any  better at recovering a battery than simply placing them on a charger capable of equalization voltage and leaving it there long enough to actually do something.

the one thing they do seem to do, is allow a badly sulfated battery that will not accept a charge to start to take a little charge when other smart chargers simply will not start to charge the battery... however a dumb charger will given enough time generally do as well given enough time.

there is also no good understanding as to what the desulfator really does to the hard sulfation crystals,
i have seen no evidence or qualified report illustrating that the crystals are broken down and the acid if returned to the electrolyte, rather than simply dislodging the crystal and allowing it to slough off the plates. 

while sloughing off sulfation allows the battery to regain some capacity it does nothing to get the specific gravity back to spec, it also removes plate active material and it is lost forever, the result is reduced cell life.

as for desulphators and agm batteries, good agm batteries will almost always come back to life and recover to near rated capacity given a long controlled recharge. i have 6 agm six volt batteries that sat inside a locked shipping container through last summers intense heat (30 odd days of triple digits) and only removed from the containers intense heat last fall... i just got them out for recharge last week

they were all dead, bad, bad bad, on me! 

i simply removed the caps, which we are told never to do, and added 6cc of distilled water, and put them on a charger for about 4 days, at 3amps and 7.5volts... slowly they came back, and all are near peak rated capacity now.

from my research agm's built to some sort of european standard (which most are) can be recovered by this method, then slowly drained to dead, attach a shorting cable overnight, then repeat the process a half dozen times or so,, the result is each extreme cycle the capacity increases.

flooded lead cells don't work that way, never want to kill them dead, much less do so intentionally, then apply a shorting strap overnight and do it repeatedly! 

anyway getting back to desulphators, there is no reason to go out and buy one or to use one in normal use of flooded batteries, further i would not recommend the use of one until all recommended methods are exhausted, that means attaching a charger with amp limiting and high enough voltage to get into the equalization range for the battery being charged (15-16volts for a 12 volt battery) and give it enough time to do its work.

i would then go the extra mile and if i still was not getting the results i want, as evidenced by specific gravity not returning to spec, i would then drain the battery, refill with fresh distilled water and put it back on the charger for days if necessary while monitoring the waters specific gravity to rise and stabilize.  given enough time, limited amperage and enough voltage, the crystals are more likely to dissolve in fresh distilled water than they are in acid. a rise in specific gravity of the water will be evidence that the crystals are being converted and broken down like they should be without being dislodged and without undue sloughing of the plate materials... after the spec gravity of the water peaks
and does not rise for 3 hours then i would drain the batteries and replace the electrolyte with fresh electrolyte of the correct new specs as stated by the manufacture.

this is a hell of a lot of work, not practical for the average diy'er if he has a 2 ton forklift battery, but certainly practical for batteries in the sub 100 lb class. of course it goes without saying there are safety concerns with working with acid, proper disposal of the old electrolyte and all that entails, however for
expensive batteries one should probably consider first doing no harm before trying other methods.

having said and done all that, if i still could not get the battery back to reasonable condition, i would then give the desulphator a go, figuring i have nothing to lose, and also figuring if it works the loss of plate material is an acceptable tradeoff.... if that didn't work then i would as a last resort ...

use edta or some other magic potion, figuring that i am poisoning an otherwise useless battery so if it comes back with the use of this crap, maybe i can get some use out of it.

no way on earth would i use a desulphator  or edta on an expensive battery to recover it without first checking with the manufactures engineering department. 

i would also never use either as some sort of preventative measure on an otherwise normally operating battery over the course of its life.  i have heard of folks buying and using desulphators and adding edta or some other elixor to their battery banks because they have heard some bullshit about that extending the lifespan of their investment... bullcrap!

one day, perhaps after the first of next year, when i get the somrad lab built and in operation, one of the things i plan on doing is this

i plan on buying a new 6 volt golf cart battery, only because it is reasonable in price, i will fully charge it, drain it, cut it apart into separate cells, taking each cell to do testing on.

i will put each in a glass jar and suspend it, refill with electrolyte, then apply a load, drain them dead
watch what happens with the formation of sulfation and crystals,   then use each method of recovery
after which do an autopsy of each cell to see just what happens to the crystals and what happens to the plate materials.

so far i know of no such test having been done, and if it has i know of no such published reported results of such a test.

we have lots of anecdotal evidence pro and con, and we have batteries of all conditions being reported on, which is a huge set of multivariables, the results of which are about worthless.

nothing would please me more than seeing a positive and negative plate suspended in electrolyte in a glass jar where i could see if the crystals are being broken down electrically and dissolve or simply being blown off the plates and falling into the bottom of the jar.

i am left to wonder why we have not seen pictures or video clips of such a test proving what actually happens to these crystals, the lack of such should lead us to conclude that the technology might not do what it claims or it might work but reduce the lifespan of the battery.

bob g

[Jens]

Thanks Bob for that thorough write-up. I too am leery of these desulfators and I would much rather buy a charger that allows for equalization. Unfortunately, these things are difficult to find. Having said that, West Marine has the ProNautic 12V 50A charger for sale at $449 and they have a promotion going that would give me $50 off that price if they had them in stock which they don't .... I have emailed them to see if they would like to do the deal even though it is not an in-stock item.

[BruceM]

Simple sustained charging at modest current, voltage limited to something at or approaching equalization (or at least above bulk charge voltage), has always worked for me.

Like BobG,  I also view the pulsed desulfators with some technical skepticism.  All technical skepticism could be quashed by the sort of photographic evidence that Bob suggests, without huge expense, and you have to wonder why that isn't presented. 

I love my 120VDC system with cheap Walmart 12V marine batteries, using individual battery shunt regulators. (A scheme developed my Manzanita Power for electric cars with AGM batteries.) There's virtually no water loss, no need for protracted equalization, and a premature death in the 3rd year can be replaced without having to worry about age matching.  (My 2 battery losses were both due to prototype hardware failures due to corrosion on unsealed boards with too fine a clearance around traces.)  At the end of 4 years, the charge efficiency was noticeably poor, so I retired the whole set when I had a cell loss last fall. I'm too lazy to work hard to save an aged $67 battery.  Twice a year I check all the cells SG, and add water.  I'm ready to go to once a year now; I'm not adding hardly any water, and have had almost no variation in water consumption between cells or batteries.  I do mini-equalization charges (2 hours) monthly.  The Manazanita Power approach to charging long series strings is a real winner in my book.  I realize I'm well outside the mainstream with 120VDC, but someday this will be much more common, unless the battery technology picture changes.

[SteveU.]

Hey BruceM you are now the 2nd fellow i know using a home brew 120VDC set up.
Any interest in taking this off on a thread of it's own so some of us can quiz you about the nitty gritty realities if using this on a daily basis?

Then you could control the content and tone.
Thinking about the battery set up to go with for the lights, maybe universal small hand held tools in my solo small shop, the chicken house and greenhouse.

Regards