Have i permanently ruined my batteries?

[WillAK]

I think I may have permanently ruined my Lead Acid batteries due to my own neglect...

I have 2x 245Ah Lead Acid which I've had constant problems with for months now, they just wont hold a charge. I've had them for just over a year now.

I've just tested the gravity with a hydrometer and it was so high the hydrometer wouldn't show a reading. I added distilled water (About 50% of what I took out) and I got it down to 1.200 so the batteries definitely need water.

My question is... have i ruined these batteries? Or would some distilled water to the correct gravity and a good charge do anything?

Thanks
Will.

 

[OzSolar]

I've just tested the gravity with a hydrometer and it was so high the hydrometer wouldn't show a reading. I added distilled water (About 50% of what I took out) and I got it down to 1.200 so the batteries definitely need water.

High would be very odd in my experience. That means they are fully under normal circumstances but off the scale makes no sense to me.

My first reaction is that something is up with your hydrometer or that you're not using properly. Don't take that personal. That comes from experience of going down the wrong trail based on something I was SURE I doing correctly when I wasn't..

What does it say when you check water?

What is the voltage of the batteries?

How are you charging and monitoring their state of charge?

You probably haven't ruined them but you may have taken some life off of them.

 

[WillAK]

The hydrometer reads 1.000 using only distilled water. But with the battery acid the hydrometer floats right all the way and goes well below the lowest reading. But when I add distilled water to this, the hydrometer goes down and i can get it to 1.200

The batteries are in series at 24v and are currently reading 28.8v being charged by 2x 450w solar panels at 45v.

I've attached a photo of the hydrometer reading with the battery acid.

 

[OzSolar]

That does appear to be off the scale. All of the cells do that? I've never heard of that nor can I think of a reason why. FWIW, I've installed and worked on a lot FLA batteries ranging golf carts to large off grid power sites going on 30 years now so I've got some experience.

Can you send a pic of the top of the battery and the battery data sticker?

When did you last check them with a hydrometer?

I've just tested the gravity with a hydrometer and it was so high the hydrometer wouldn't show a reading. I added distilled water (About 50% of what I took out) and I got it down to 1.200 so the batteries definitely need water.

I'm not understanding this. You pulled electrolyte out the batteries?

How were you determining they are not holding charge? Severe drop in voltage?

If it was me I would take those batteries up to at least 30v's for a few hours and stir up the electrolyte (aka equalize) then check the cells again but I'm afraid to suggest that having no idea what's going there yet.

 

[Checkthisout]

You took electrolyte out of the batteries and replaced it with water to get your sg readings to go down?

 

[Checkthisout]

SG will go very high if battery water levels are low. Was the batt low on water at the time you tested?

 

[time2roll]

If a bunch of water was just added.... wait 48 hours and check again.
Otherwise I recommend an equalization charge (at about 15.5 volts) for 30 minutes a day for maybe a week and see if some capacity is regained.

 

[HRTKD]

When I had lead acid batteries I did test the specific gravity. I was shooting for 1.265. There is a "normal" temperature to use for that reading. I believe is it 80° F. I didn't do the hard calculations but tried to take the ambient temperature into account. Battery fluid that was tested went right back into the cell.

I never had my fluid vary much from the target. Either your test device is off or your fluid is a problem.

 

[OzSolar]

SG will go very high if battery water levels are low.

I would politely offer that based on my experience I do not think this is correct.

I've maintained and continue to maintain quite a few big battery banks built with 2V cells from manufacturers that supply nice documentation. I do not recall ever reading anything about that in the manuals. To be sure i just now took a look at the SG section in the Rolls Surrette manual and can find no mention of SG being related to the electrolyte level.

 

[OzSolar]

Either your test device is off or your fluid is a problem.

That was my initial thought but the OP did say they got 1.000 testing water with the same hydrometer. I've have theory but until OP supplies a picture of the battery's label I can't be sure.

 

[Checkthisout]

I would politely offer that based on my experience I do not think this is correct.

I've maintained and continue to maintain quite a few big battery banks built with 2V cells from manufacturers that supply nice documentation. I do not recall ever reading anything about that in the manuals. To be sure i just now took a look at the SG section in the Rolls Surrette manual and can find no mention of SG being related

Well, what happens to the acid concentration as the water evaporates?

If the acid also evaporated we would top off batteries with electrolyte instead of water.

OP, take a photo of your cells with the caps off. Does it look sulfated, etc?

 

[Noday]

Please let me break in by saying that the specific gravity is the ratio of the weight of the electrolite solution to the weight of an equal volume of water at a specified temperature, usually 25 C.
So, the specific gravity changes:
- by temperature, due to the electrolite volume contraction and expansion
- by density, due to evaporation and refilling with distilled water
- by state of charge, due to chemical exchange with the lead plates

I've only seen off scale hydrometers on fully charged batteries with the electrolite way below the low mark and at freezing temperatures.
But I don't remember seeing values as OP.

To OP: If the gravity measured by your hydrometer shows 1.00 with pure water and 1.20 after adding about 50% of pure water to the electrolite just removed from your battery, my humble opinion - by the few information you provided - is that you're having "constant problems for months" because the electrolite level and density has always been off chart.

I don't know the real state of charge of the lead plates, so I can't know what the real gravity should be to adjust the electrolite density ratio accordingly. Anyway, since the plates are probably already sulfated, I will just add water until the specific gravity will be at 50% SoC (about 1.19) - by making sure the electrolite level is above the plates - and float charge the batteries while checking how much the density will be increasing.

Your batteries will probably need a serious wash with magnesium sulfate and a refill with new electrolite solution.

 

[OzSolar]

Well, what happens to the acid concentration as the water evaporates?

That reasoning does make sense until you realize that it also means that specific gravity (SG) would have to be low when the electrolyte level was high. Right? I'm not arguing, rather making sure someone reading this thread in future gets the correct information.

Battery manufacturers would give detailed instructions about what level the electrolyte has to be when measuring specific gravity and they don't.

Below is from the Rolls Battery User Manual No mention of only checking the SG at certain electroylte levels.

SPECIFIC GRAVITY The specific gravity of electrolyte in a battery is the most accurate measurement of actual state of charge. To determine if the batteries have reached full SOC, testing should be done when the charge cycle has been completed and the battery bank is resting a Float voltage. The specific gravity (SG) reading should remain constant for 3+ hours for an accurate 100% SOC reading.

 

[Checkthisout]

That reasoning does make until you realize that it also means that specific gravity (SG) would have to be low when the electrolyte level was high. Right? I'm not arguing, rather making sure someone reading this thread in future gets the correct information.

Battery manufacturers would give detailed instructions about what level the electrolyte has to be when measuring specific gravity and they don't.

Below is from the Rolls Battery User Manual No mention of only checking the SG at certain electroylte levels.

SPECIFIC GRAVITY The specific gravity of electrolyte in a battery is the most accurate measurement of actual state of charge. To determine if the batteries have reached full SOC, testing should be done when the charge cycle has been completed and the battery bank is resting a Float voltage. The specific gravity (SG) reading should remain constant for 3+ hours for an accurate 100% SOC reading.

Do they instruct you to correct the water level before initial testing?

The op isn't being clear. He said the battery needed water but I can't tell if he thinks they needed water because the sg was high and he believes the acid needed diluting with water or because the actual water level in the battery was low.

 

[time2roll]

No matter the battery, if adding a bunch of water the top section will be heavily diluted and need a few charging cycles to un stratify the mix.

 

[acdoctor]

FLA is fairly robust so long as you charge them and keep the plates submerged.
Or you can just replace them.
I think the OP is giving some non standard information but, 1 year old he may need to look at warranty if output is low.

 

[Checkthisout]

FLA is fairly robust so long as you charge them and keep the plates submerged.
Or you can just replace them.
I think the OP is giving some non standard information but, 1 year old he may need to look at warranty if output is low.

Seen that happen a few times but over a few decades. Rare but loud!

 

[OzSolar]

he op isn't being clear. He said the battery needed water but I can't tell if he thinks they needed water because the sg was high and he believes the acid needed diluting with water or because the actual water level in the battery was low.

The OP was pretty clear about having a SG higher than his hydrometer would read but that was about it. Was it just just one cell? Had the OP ever checked the batteries SG before? Did they ever hold a charge? And so on....

No has offered nor I can't think of a normal situation where the OP would find the SG higher than his hydrometer would read. Perhaps a chemist will chime in?? I really want to know.

One explanation is a faulty hydrometer and/or improper use which have been offered several times.

Perhaps another explanation is used batteries. Maybe someone dumped straight sulfuric acid in there trying to refresh them before the OP took possession??

But.... there still is no provable situation in the normal life of a flooded lead acid battery where SG increases as the electrolyte level decreases or vice versa. It's just not how it works and if that were the case then using a hydrometer wouldn't be the go to standard for checking the state of a charge. You have to use a correction chart that compared electrolyte level to SG to stage of charge. No such thing exists.

 

[Checkthisout]

The OP was pretty clear about having a SG higher than his hydrometer would read but that was about it. Was it just just one cell? Had the OP ever checked the batteries SG before? Did they ever hold a charge? And so on....

No has offered nor I can't think of a normal situation where the OP would find the SG higher than his hydrometer would read. Perhaps a chemist will chime in?? I really want to know.

One explanation is a faulty hydrometer and/or improper use which have been offered several times.

Perhaps another explanation is used batteries. Maybe someone dumped straight sulfuric acid in there trying to refresh them before the OP took possession??

But.... there still is no provable situation in the normal life of a flooded lead acid battery where SG increases as the electrolyte level decreases or vice versa. It's just not how it works and if that were the case then using a hydrometer wouldn't be the go to standard for checking the state of a charge. You have to use a correction chart that compared electrolyte level to SG to stage of charge. No such thing exists.

Very low water levels but fully charged will net you high readings but yes, you're correct. It would take a lot of weird stuff to get there.

The OP removed acid and added water to adjust his high sg.

It's probable he had low sg at some point and corrected it by adding acid.

Looks like he's gone awol and we may never know.

 

[OzSolar]

Looks like he's gone awol and we may never know.

We probably won't. I would love to know what sort of batteries they have.