Winter battery storage

[VicS]

[ QUOTE ]
It is my understanding there are at least two different types of EDTA products

[/ QUOTE ] Which are?

Where did herbal tea come into it. I missed that!

Earlier you told us that EDTA was a heavy metal. That was rubbish. I suggest you dig out one or two old chemistry books and come back with some facts.

 

[leadersail]

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EDTA usually as a negative PH value.

By altering the PH value the EDTA can be increased in PH value which extends its use to different applications.

I did say EDTA+

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here is some totally irrelevant reading for you that will not aid anyone thinking of winterising batteries but does show different types of EDTA.
http://www.cababstractsplus.org/google/abstract.asp?AcNo=20043149428

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You can do your own search for the different uses of edta and how many variations there are now...........

I don't know how long it is since you learnt about chemistry but time brings developments.


Facts

I have regenerated old defunct batteries into fully serviceable units that have gone on to provide an extra 6 years of life before I have sold the boat, they could well be still serviceable 10 years on

 

[VicS]

[ QUOTE ]
EDTA usually as a negative PH value

[/ QUOTE ] Only relatively high concentrations of the strong acids (sulphuric, hydrochloric etc) have negative pH values. Note that pH is written with a lower case p
Perhaps you can quote the pKa value for EDTA as I cannot find it quoted in any of my reference books. I doubt if it will prove to be a strong acid.

[ QUOTE ]
By altering the PH value the EDTA can be increased in PH value which extends its use to different applications

[/ QUOTE ] The pH value of any solution can be increased by the addition of an alkali but it is true that the stability of EDTA complexes is pH dependent and that is something which can be made use of in analysis of metal alloys by classical wet chemistry methods.
[ QUOTE ]
here is some totally irrelevant reading for you that will not aid anyone thinking of winterising batteries but does show different types of EDTA

[/ QUOTE ] As you say the effect of EDTA on buffalo meat is irrelevant to winterising batteries. I cannot see any mention of these different types of EDTA you seem to know about, just different % mixtures of EDTA and ascorbic acid.
[ QUOTE ]
I did say EDTA+

[/ QUOTE ] What is EDTA+ then?
[ QUOTE ]
I don't know how long it is since you learnt about chemistry but time brings developments.

[/ QUOTE ] Well now I think my first formal chemistry lesson was probably in September 1956, Mr. McChesney was the chemistry master, and I have been learning ever since. You never really stop when it is your profession.
[ QUOTE ]
Facts
I have regenerated old defunct batteries into fully serviceable units that have gone on to provide an extra 6 years of life before I have sold the boat, they could well be still serviceable 10 years on

[/ QUOTE ]
I am pleased to learn that it has worked for you. What I would like to know about is the chemistry involved. Just how does it work.

BTW I forgot to mention that I am a member of the Royal Society of Chemistry.


VicS MRSC

 

[jimbaerselman]

VicS, Not often someone gets provoked into displaying their credentials!

His 'herbal tea' bit was a rather good response to my underlying (but unstated) suggestion that EDTA may be snake oil, unless there was evidence of peer review of the observations being made . . .

And, to take the heat out of this, we're looking for alternative evidence, in addition to his personal experience, that batteries can be restored with EDTA. And, at present, I don't accept the sales company's evidence. They have too strong a personal stake.

Makes me think of that wonderful chlorophyll pill sales scam for 'freshening the breath'
"Smell that goat on yonder hill
Feeds all day on chlorophyll . . ."

Or little tapes to hang on the back of the car to discharge static electricity, thus curing car sickness . . .

Many more wonderful examples of the triumph of marketing over reason.

 

[leadersail]

[ QUOTE ]
VicS, Not often someone gets provoked into displaying their credentials!



[/ QUOTE ]

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Thats because everyone knows there are good professionals and bad ones in every field
Quote found on quick search
.................................................................................
EDTA4- is used to "trap" trace amounts of transition metals that could potentially catalyze the decomposition of the product
....................................................................................
I am not a chemist, I didn't pursuit it as a subject beyond basic level.

EDTA+ regenerates batteries and I recommend all people reading this to add it to their Lead acid batteries new or old.

just because a prolific poster comes here and posts all sorts of none relevant twaddle and complains at my spellings doesn't
mean EDTA+ does not work.

EDTA+ is used in industry to clean metals from things, the metals can then be recovered.

In a battery we are taking the sulfate coating off the lead plates and releasing sulfate back into the sulfuric acid.

It works, I have dosed up over 10 batteries.

a car battery had no effect.
the other 9+ all worked well
1 of the 9 developed a fault some 6 years after the dose, I left a spanner over + /- , the spanner got hot and that battery had to be replaced.
The others have all worked indefinitely either because I have sold the boat, given to a Friend to get away for the weekend or still in use now.
At least 7 were ready for the dump prior to mthe dose.


Just because I am not a chemistry head should not preclude me from joining the thread should it ?

I don't fully understand the cracking process of petrol but I still put it in my car, does that make me a bad driver ?

Please read this link VicS , I hope you can understand how it works, if it really is just a placebo I best know.

http://www.chem.purdue.edu/gchelp/cchem/polys2.html

 

[VicS]

[ QUOTE ]
Please read this link VicS

[/ QUOTE ] I had a look at this but it just shows us the structure of the EDTA molecule and one of its complexes. Tells us nothing about the use of EDTA to rejuvenate batteries I'm afraid.
That it forms complexes with di- and trivalent metals is well known. That it forms a stable complex with lead is easy to verify. What I cannot find is a satisfactory explanation of the mechanism of its ability to restore batteries or the detailed results of a properly conducted investigation into that without some of the idiotic statements you made in earlier posts.

Maybe it works, there are plenty of claims that it does.

 

[jimbaerselman]

I've emailed two battery manufacturers for their comments. If this system works, they'd be very interested. If it doesn't, they'd know because they'd have tried it out . . . if they're awake, that is!

 

[leadersail]

If I was studding Chemistry at Cambridge I would happily accept the statement 'Idiotic' , however on a boat forum I have tried to explain how it works by a laymen to a laymen.

The term heavy metal perhaps was confused from what I read a decade ago when I first used it.

I believe EDTA+ was used for cleaning heavy metals, something like a copper mine recovering metal from a water used in the process could edta+ plus copper then be described as a heavy metal ?????????????

I read it and then it became non relevant.

I believe have I have given an account of how it it designed to work in theory

During the charge process the EDTA+ attach's its self to the sulfate.

during discharge the sulfate is released back into the sulfuric acid.

this keeps the lead clean so it can conduct cleanly with the acid.

Over the years my starting batteries have shown 10.5 volts and engines would only click

with EDTA+ added 3-7 days latter and 13.5 volts on the meter and engines start.

after several months of charging/discharging (normal use)
a weekend at anchor the same previously duff batteries were still starting the engine.

There is no point in me going to the battery dump and dosing with EDTA+ as I already know what will happen and you would not believe me but I urge you to conduct this very test, ideally you should wait until April when there will be a queue at the marina dump of moaning boaters " this was new 18 months ago and my boat will not start"
this is an ideal battery, others may have genuine faults that EDTA+ can not rectify ( buckled plates etc).

My disappointment is I do not post very often on PBO, I feel I have a valuable contribution to make with this post aimed at saving others hundreds of pounds this spring and tons of battery waste into the environment, you are clearly a respected poster that carries a lot of weight and my advice has been wasted, a shame for us all including you.
Even if you are one of the wealthy posters (clearly done well for yourself as a chemist and retired during prosperous times) it is not only the money /environment we are saving

option 1
Spend £100 on a new battery bank, risk chipping gel coat in/out.
risk dodgy back
risk acid in car boot
repeat process in two years after wrecked boating weekend

option 2
mix powder EDTA+ into battery water bottle, shake well
remove battery plugs, squirt edta+ into each cell.
screw tops back on
charge overnight

thats it until you sell the boat, no more new batteries required
( I have tested to 7 years after I have added to batteries of an undetermined age).

Has anyone got a battery in their garage waiting to go to the dump ?
(old car ones no good, just boat/caravan ones that are left half charged for months that sulfate up the plates)

 

[leadersail]

Is it in the interests of battery manufacturers for produce a battery that lasts for 10 years ?

 

[leadersail]

Dear Jim and Vic,

I give up.

Unfortunately my current batteries that wouldn't hold their charge are already dosed up with EDTA+ (three years ago), I hope you don't mind me still using them, I will report back if they pack up before I sell the boat.

By the way, I have found once dosed up with EDTA+, it is very rare to have to add water, I cant explain that.

regards

Leadersail

 

[jimbaerselman]

Don't give up. I'm hunting for independent confirmation of your claims. When I find it, I'll post it and praise you . . .

 

[VicS]

[ QUOTE ]
I've emailed two battery manufacturers for their comments

[/ QUOTE ] It'll be interesting to hear what they have to say.

In the meantime I have been trying to discover the mechanisms by which this treatment is effective.

A lead acid battery has lead plates (the cathode) and lead dioxide, supported on a lead grid (the anode) immersed in an electrolyte of sulphuric acid (dilute, not concentrated).

During discharge both plates are converted to lead sulphate, which being insoluble is deposited on the plates. During charging the reactions at both plates are reversed, lead being reformed at one and lead dioxide at the other. During the life of the battery and especially if it is left in partially discharged state a build up of lead sulphate occurs which is not reconverted to lead or the dioxide during charging. Eventually this leads to the battery performance falling and it becoming unserviceable.

If EDTA is introduced into the battery (probably done by adding it as a solution of the tetrasodium salt) it dissolves the unwanted lead sulphate on the plates, taking it into solution as a lead-EDTA complex. During subsequent charging it seems that the complex is itself broken down. The EDTA is released back into the electrolyte to continue its work without the need for further additions while the released lead reacts with the sulphuric acid to form insoluble lead sulphate which falls to the bottom of the cells.
There are two knock on effects here, the precipitation of the lead sulphate in this last stage represents a loss of sulphuric acid from the electrolyte and the non recovery of any lead dioxide that had been converted to lead sulphate, then dissolved by the EDTA and finally deposited as lead sulphate in the bottom of the battery represents a loss of lead dioxide from the anode. Loss of lead from the cathode by a similar process is hopefully insignificant compared with the amount of lead that makes up the cathode. Maybe there is adequate lead dioxide on the anode for the loss there to be insignificant as well.

Overall then a loss of sulphuric acid and maybe of lead dioxide will cause a reduction in capacity although restoring the serviceability.

There are two aspects of all this that I am left to ponder over. Firstly why does the EDTA not interfere with the production and "decomposition" of lead sulphate in the normal discharge and recharge cycles causing a slow but continuous reduction in capacity? Secondly why does the EDTA not recombine with the lead sulphate deposited in the bottom of the battery? Maybe both do occur. The first slowly until the battery eventually does become unserviceable or dies from some other cause and the second continuously reforming the EDTA complex only to be broken down again during recharging.

Food for thought.

BTW on environmental grounds do not use EDTA in your batteries as it will eventually find its way into the environment where it does not biodegrade!