Renew dead battery with Epson salt?

Hi all,

I have 16 X 200Ah dead deep cycle Batteries.

My defective EASUN MPPT inverter charged the 48v setup with 78v..
The result is $4500, "useless" lead.

Needless to say I never want any EASUN product ever again.
Yes, all products can malfunction, but the way they gave "support"...
Even for Chinese company, really bad.

Anyways...
I am discharging them now.

My solar charger told me they where fully charged at 58-59v ..(in 48v setup)
With 140watt discharger..
The voltage already dropped fast to 10.4 volt..



This is with 8*12v "fully charged" (defective) 200ah LA battery.
1600ah@12v

Once they are depleted to 1v I will take out the acid and replace it with Epson salt (+water) and recharge the batteries to full.
After a week of fully charged, the batteries will be depleted again, Epson salt mix will be removed, washed out and the battery acid will be put back.

As I have max 30A as charging capacity, I'll do 4 batteries at the time.
(Now only 8 discharge)

After this recharge and see what happens!!

These batteries are not old.
They are from March last year, (8) and September.. (8)

Before I recycle them as old lead, I want to give it a try. I'm not sure if this will work as they are not dead due age but overcharge.

Try draining acid then refilling a battery with distilled water, charge until the sg stops rising. Rinse and repeat, then fill with new acid.. Charge it fully, followed by an eq, then adjust acid to sg to 1. 265.

I had a L16 blowup this winter at my camp, blew the top off the battery... Water miser caps where blown to pieces..

Epson salts, will get the sg to rise but it will be the end for your Batts..

What is "sg"?

DaWiFiGuy said:

What is "sg"?

Click to expand...

Figured it out. SG = Specific Gravity

I am still getting used to all the abbreviations that being used in this forum.

Overcharging concentrates the acid, and degrades the plates badly... also, they oxidize in the low electrolyte levels...

you can try removing the acid, but replacing the water, charging, then draining and refilling with new acid might get some cells working again.

good luck!

Mtour said:

Try draining acid then refilling a battery with distilled water, charge until the sg stops rising. Rinse and repeat, then fill with new acid.. Charge it fully, followed by an eq, then adjust acid to sg to 1. 265.

I had a L16 blowup this winter at my camp, blew the top off the battery... Water miser caps where blown to pieces..

Epson salts, will get the sg to rise but it will be the end for your Batts..

Click to expand...

My batteries are dead.
Really dead.
8x 200ah have 40ah left discharge down to 10.5 volts.
5Ah per 200Ah battery is dead enough for you ???
Can not get any worse!!!!
( Might explode, but that's different story)

I'm now draining them totally.
This will increase the PH of the battery acid, and reduce the floating around particles.
(So I read)

Many articles on how to do the Epson salt process

I will collect and store the acid.
And re-use it.
Maybe make one battery with brand new acid, and I can see what will work best.

As you can understand, I don't want to spend a lot of money on them.
If I can re-use acid for free, I will.

16* 200Ah is a lot of liters!!

Might want to leave the caps off, the L16 that exploded had been discharged to 11v a week earlier. It charged fine after the complete discharge, exploded under a very light load. I was standing over it 5min earlier, ended up walking into a dark room full of acid fog... Battery acid dripping from the ceiling.. Not fun...

You got lucky!!

LA can be dangerous!!
I have read quite a lot about acid burns from exploding new and older Lead acid batteries.

After Epson salt even more.

The batteries will be out in the open.
I probably make "vent" from ductape.
One side stuck, other side double tape (on the sticky side) as Flexible lid.
Just closed enough to keep the dust out.

They will charge slow as my father is law have only 2 panels.
And it will run only a 250 watt water pump. (Probably 24/7)

My options are simple.
I can sell them for old lead, or try to get new life in them.

I have 16 to play with.
I can do different things for different cells.
As there are different suggestions on the internet.

Then I have real life proof what will and will not work!

Ouch that sounds like a crappy situation! Sorry for the loss, that's a lot of money.

For next time add a voltage alarm point so if it goes past say, 55 volts, it triggers an alarm. Add a midpoint alarm too, that will tell you if the bank is going out of balance due to a bad cell. hydrogen alarm is good too, if hydrogen levels go up it's often an early indication of an issue.

Hopefully you do manage to somewhat revive these.

If only life was this simple.....

Not to put your idea down, naturally I have monitored the battery voltages.

And that is where the problem starts.

When you charge 24 Volt batteries at 48 Volts, (your charger set at 48 Volts)
You measure at the leads not 48 Volts!!
You measure the "normal" voltages you would expect.
Yet, you will damage the batteries by charging it at too high voltage !!

In my simple mind I am thinking that it really must reach the high voltage before it becomes a problem.
Sounds "logic".

Apparently things work different in the electric magic world of Charging batteries!!

You might have noticed that your battery charger gives at start like 14.5 volt, but doesn't charge your battery to 14.5 volts.
My batteries got 19.5 volt.

Maybe some day I understand the total chemical or electric logic behind it all.
As I'm now over to lifepo4, I don't care that much what really happened.

There are now more protection parts in the chain.

But still...
The voltage that the MPPT is giving to the batteries is not the same I measure.
It "gives" 58 volts.
And shows 53 Volts.

And this, is really impossible (?) To measure when the batters are connected.

Like most people, I don't start measure the output of my charger to see if it matches the description.

Many lead acid chargers you can't even measure, as they are "protected" that they need to have connection to the battery before it starts to work.

Next time, with same kind of defect, problem will be sadly the same.

And how did I know?
Watts, amps volts..
They are supposed to be in balance, Yes?
What I saw and what I calculated had that much difference that something must be wrong .
(+ After 10 days my batteries began showing signs of damage, they couldn't hold charge for a night.
800A@48v is supposed to be a lot of kWh..
While the charger said they where fully charged, lights go out in the night.

After this I started to find what was wrong, Mixing, matching, measure...
And had the amazing results of 78volts output on 48volt charger.

But how to find at start??
Especially if a charger won't give voltage before it's connected to a battery (like most LA chargers)..

Probably impossible task.
We just trust the label that tells us "12v lead acid charger"