Adding De Ionised Water to Old AGM Battery

I don't know. But if you are looking at an option of having a battery that doesn't work, or a battery that might work with a refill, I would go for it.

Bear in mind, this is something that I would do, and not meant as advice one way or the other.

The precautions that I would take, would be to have a charged water hose handy while refilling, wear eye and body protection while refilling, and not storing the battery in the shed until I knew for sure that it was stable.

Use distilled water if your water comes from limestone sources. Or go to your auto parts store and purchase battery acid. I think this is the manufactures worry that tap water may react with the sulfuric acid.

Or the manufacturer just wants to make more money because the customer will buy a new one when the old one is dry.

That's what I think.

They ain't cheap either!

DO NOT TOP UP A BATTERY WITH ACID.

PLEASE....PLEASE...PLEASE.

a qualified battery shop might be able to replace spilled acid. But this was not the problem.

I agree with you on that one. I would only add acid if electrolyte was lost from the battery through spillage.

You need some battery acid from the parts house, and:

PulseTech's Xtreme Charger

And:

VDC Electronics Battery MINDer

And, maybe even:

Battery Life Saver

Is Battery Impact.com a wholly owned subsidiary of LynDoor^TM Industries?????

Shhhhhhhhhhhhh!
Recent acquisition.

We are selling off the best product lines, at a loss , and most of the machinery, then moving the rest off-shore.

We get a tax credit for the paper loss, no taxes on the machinery, (we used the corporate express depreciation loop-hole) and get a tax rebate for all the off-shoring expenses.

Sweet deal!!!!!!!!!!!

They say that you must never add acid to a battery either. They recommend it even less than water.

That's up to you. Just check the specific gravity and pH of the solution and go from there.

That's quite difficult as the electrolite is soake into the fiberglass mats between the plates. I have put about 1 litre of de ionised water in the battery today and the battery is looking wet inside now.

Right. Maybe litmus paper?

I don't know.

I can't get it to go to 20a. The only way to do that is to put the voltage up so high that the battery will become damaged. It has been on charge for 24 hours now and the current is at 1 amp at 14.6v. I can hear bubbling going on inside probably because I have soaked the glass mats in de ionised water. The starting current when I initially put it on charge was 5 amps so there is something strange going on.

First try to discharge the battery again. As long as the amperage doesn't exceed say 10 amps, the voltage is NOT important to revive the battery. I've done it with 30 Volts in the past. You just need to observe it during this time. But first discharge again.

if the manufacturer says to never do this, why the hell did you open it and do exactly what you were told to avoid?? and now you want someone here to save you. good luck with that.

Someone got out of the wrong side of his tent this morning...

...and someone else isn't listening.

"within a few minutes" shows only a surface effect. It takes time to induce the entire mat. The battery goes quickly back to 12... is normal since the "fake load" has not a lot of "energy" and gives it to he rest of the plates.

4 amps takes 3 days and nights to charge your battery.

When we were young with limited funds and our battery went dead or near dead we listened to an old man that was quite handy and dumped the acid into a suitable container then poured hot water into the battery and swished it about as best we could and dumped the water out, this was done several times and a lot of loose material was removed from the battery. We then installed the acid after filtering it and recharged the battery topping it up with distilled or rain water. Many times this trick brought a battery back to life for a period of time. Thinking was that loose material was shorting out the plates especially at the bottom where one could not see what was happening. I even remember my father replacing cells from other batteries as in those days the cells were sealed with what I would call roofing tar. He had mixed results often keep some machine operating.

It does seem like a good idea. I was going to get 2 Trojan 105 6v flooded batteries but these were not specifically designed for solar power. They have a T105-RE for that but there is none on Ebay at the moment.

Here is a picture of the top of the plates. None of them are bent. There does seem to be a small amount of white stuff on top of them but I pushed the fibreglass mat out of the way and there isn't as much white stuff between the plates.

It can be that 1 element is not cooperating and keeps the current low. You can check this with observing the cells individually. Perhaps 5 are bubbling and the 6th not. When you discharge the battery and leave it for a few hours the voltage usually goes under 12 volts (like e.g. 5 X 2.4 or lower). This means that 5 cells have a load and the 6th doesn't pick up. ( a specific low resistance battery meter shows this immediately - but most digital meter have a too high impedance and measure through the bad cell too) With your 1 amp, the chance is about zero to revive the battery, That is why it takes a cannon. When the battery is discharged, force a high current through all the elements with too much voltage. The isolating barrier needs to be broken and this is your last chance to do it. Observe the temperature well, because the battery can just explode with this test when it runs too hot) Most of the batteries fail on one element and show between 10 and 11 volts after a while.

Some professional big batteries let you work on each element. Once you find where the lead connection is made under the plastic cover, you might tap the bad one and work on that only. I did that before with drilling a hole and putting a self tapping screw in the bridge. But you need to now what you are doing. Sparks can ignite the hydrogen that escapes out of the openings.

I know all the theorists here will shoot me for providing a non safe practice, so do it at your own risk. I had once a battery acid shower in my face and because a friend immediately showered me with the garden hose - outside with freezing temperatures- I had no visible damage. (perhaps brain?)

So nobody needs to attempt to make me crazy, because I have passed that.

I have had the battery on an equalization charge for over 8 hours now and the current has been at 1.4 amps the whole time. The current on an equalization charge is supposed to rise gradually.

It is not going to happen overnight. The 1.4 Amps is that the current, build up after discharge? When the battery is discharged, that is the current that counts. When I see your figure you have some gain, but it is still along way to go.

All the elements are in series, so the one with the high resistance determines the current through each of the cells.

The 1.4 is by far not enough to break through and remove (if possible) the chemical build up on that low cell.

If you cannot raise the voltage high enough to get a higher current, you will need to make a fix for that. I did it a few times with an isolation transformer and a variac with bridge rectifier.

You need to monitor this process carefully and keep the temperature of the battery within acceptable limits. What you do is about the same as with battery formation after being assembled. Your need current to break through (isolating) crystals on the plates. Only there you have about the same conditions for all the cells. Voltage applied is not that extreme.

In your case, unless you find a way to work on the specific bad cell, you need to go extreme. Almost all of the voltage will be over the bad cell. ( Ohms' law - resistors in series - 5 low values and one very high value - the high value resistor gets the voltage and determines the current)

You seem to make some progress, but with what you use, it can probably take 3 more months to make a battery out of your box again)

On condition that there is adequate lead on the plates left.

I concur. Such a battery in my battery shop, we would use for training the new guys. Training them in patience. Never expect to get it to work, but once in a while...there would be success.

We would never allow them to used on aircraft of course, but sometimes the Zamboni batteries would do this, or the fork lift batteries would do this. I looked at it as a challenge and a hands on learning opportunity. On our own time, of course. Mostly, they ended up being sent back to re-cyling. Clearly somebody decided to send it to EBay instead of re-cycling. Confirms my opinion of EBay...grin!

Yes, if you buy cheap you buy again. Makes me worry a little about the new 100 watt solar panels I got for £95 each. I haven't been able to test them yet.

All depends on where you buy. We have sold prime stuff for less. Lowest price ever for 125 Watts was $110.00. Sometimes you go that low to sell a container load. So chances may be good. Are these 12 Volts (19.7-21 Volts open circuit) ??

I got in touch with someone from Lifeline batteries and he said to do an equalisation charge for 8 hours at 15.5v. I can get 10 amps into the battery when I set my boost converter to 17v. If I put it any higher, I will overload it. It starts making squeaking and buzzing noises at high currents. I will keep it on all night and see if there is any improvements. My converter can do a maximum of 60v

Hydrogen head

That is all right for working batteries that have the 6 cells working. It is about time you check the 60 Volts over the battery and see what happens. There is no way you will overload the battery, unless the bad cell is short instead of quasi- open. But if that were the case you'd measure way higher currents than the ones you are talking about.

As Yusef also said: most of these bad batteries are to recycle. What I told you is how to TRY to revive your bad cell. You will NOT overload your battery with your setup while checking the amperage and keeping it in the ranges, I said before.

A client of mine formats 3000- 5000 deep cycle batteries per day. And to get the job done - for a 200 Ah/12 V battery the currents are peaking sometimes up to 30 Amps. This is done with 180 elements in series, straight from a 3 phase 380V net with a insulation transformer between.

Seems to me that your inverter is also a buzzer? Handy.

It is that or dead at birth. In your case revival or death. Since you are good in opening batteries, you still can use this battery for 10 volts if you discard the bad cell.

Throw the damned thing away.

Attempting to equalize an AGM is fraught with dangers.

It will start to gas excessively (and especially so if you have a partially shorted cell) long before you get the cells to the voltages that are being suggested that you try here, and once that happens the valve will either pop or the battery will deform and possibly rupture. Either way, you won't get a good result.

I flooded it with de ionised water and it is at 16.2v at 3.5 amps on my charger.

Then keep it open to atmosphere, because at that voltage it will gas profusely (that's assuming there is any effective chemical action left). Batteries don't last forever, and once they fail, despite all of the best efforts and old wives' tales, there are no fixes.

At 16+volts you should be getting quite a bit more current into the battery than what you are seeing.

The reason that this is not occurring can only be the increased internal resistance of the cells. This could be a result of one or more partially open cells (collapsed matrix) or poor electrolyte quality (as happens when you add water to an AGM).

There are two effects to consider here:-

1. If the battery is left in a discharged state for prolonged periods, the soft lead sulphate that has formed on the negative plate morphs into a solid crystalline form that cannot be changed back. The cell's active material is thus reduced, electrolyte-plate contact is reduced, charge acceptance and therefore capacity is also reduced.

2. When an AGM dries out, it's only the water that's lost, this leaves the electrolyte stronger than intended and at a lower level in the battery (at SG above 1290, the electrolyte become highly aggressive), but it also allows the fibreglass matting above the electrolyte to dry out and shrink away from the plates.

The consequences of this are heightened corrosion of those parts of the plate that are in contact with the now stronger acid, plus loose plate material being able to shed from the dryer parts above.

This allows the loose lead to fall off the plates and be lost to further chemical action, it builds up in the bottom of the cell and, once it overflows the sediment trap, eventually causes a soft short, further lost capacity and lower rested terminal voltage.

Either way, you won't fix it.

I am getting better resting voltages. After I first charged the battery, It would go back down to 12.4. Now after all the high voltage charging I have been doing, I can get it to rest at 12.6v. I won't stop the treatment until I get a resting voltage of 12.8 or higher.

It is a learning experience. I for one am like, totally stoked that you are sticking with this. You know, as we all do, that the results may not be great, but science often ends up with a pile melted down stuff. Clearly the time and trouble you have gone through to get a maybe good battery is not worth it if all you wanted was a maybe good battery. But the knowledge and experience is worth every bit of trouble.

Maybe its because we were so bored in the Airport Battery Shop back in the nineties that we HAD to study just to stay awake! We were encouraged to experiment a bit, and a lot of what we did (changing acid for instance or pulling cells) was actually SOP. That being said, sometimes things go sideways quickly. I personally survived four major thermal runaways in the ni-cad side of my battery shop, and dozens of little ones. Led to my preference for lead-acid in heavy load applications. We did all the stuff you are doing, with state of the art (for the time) equipment.

Reversing sulphation is difficult but not impossible. The cleaning of the crap in the bottom was a much larger job. Worth it on the big two person truck batteries, I think I saved the military four or five thousand a week just reconditioning those.

And yeah, they don't do that any more...just send them to recycling.

I gave you a good answer because by and large, it is dead on accurate. The question of "will he fix it" has since been answered, but I do have to admit that even as "fixed" as it is, I would not trust it to live in the truck I need to make a living!

After much more equalizing, the battery is now holding 12.8v even after 2 days doing nothing. It also holds up better under load. So it seems that saturating the battery with water and equalizing it at 16.2v for several hours per day works quite well.

I connected my boost converter the wrong way and one of the mosfets went pop. I replaced it with a much more powerful IRFB4110PBF power mosfet.

Thanks to everyone for all their comments and advice.

I am happy for you. Many batteries are discarded way too early. This all will change as values will have to be reviewed. Thank you for sharing this with the community. Good luck.

You're not finished yet.

Terminal voltage only tells you that the battery has achieved a charge.

Take away 90% of each set of plates on a 100Ah battery and it will still show a fully charged terminal voltage, but will have only 10% of its original capacity

Put a known load on the battery and see just how much of the original capacity it still has.

A 225Ah deep cycle battery should be able to power a 120w load for around 22 hours, or a 500w load for about 4 hours before the voltage falls to 10.5v.

I will be interested to know the result