Old Battery like new again.

[Rooster 191]

I read on another forum how to "rejuvenate" a dead battery. Now I am no battery expert or chemist, so I cannot tell you how or why this works, but it did for me.

To test the process I used a 900cca battery that had been sitting on a shelf, outside of my garage for well over 2 years.

You dissolve a couple of teaspoons of Epsom salt into distilled water by heating the water Then you replace some of the electrolyte with the saline solution and slowly recharge the battery.

Now what I actually did is use my miniature distillery,AKA coffee pot! I put a few teaspoons of epsom salt in the pot then turned it on and brewed up a distilled saline solution. The battery had sat long enough about an inch of each cell was low. Poured it in and charged the battery overnight.

It worked!!!!

This battery cost about $100 new and is now holding a charge again. Since my b100 has a charging issue, I have been using this battery to jump it for about a week now and it still cranking it like nothing.

I don't know how long it will last, but as of now it is working!

[rmaynard 14,898]

My father used to do this on his old 6 volt batteries on his tractor and in his VW bus. Epsom salt works by cleaning the build-up of oxidation from the lead plates, reducing the internal resistance in a weak battery and therefore allows a small amount of extended life. I used to work for a man that had VW Beetles as company cars. He was cheap and hated to replace batteries. He used to turn the battery upside down for 24 hours. Don't know what that did, but it seemed to work on some sealed batteries.

[SousaKerry 500]

My dad uses a battery reconditioner on the farm plugs it in and it takes a few days but it knocks the scale off the plates electrically somehow.

[bowtiebutler956 649]

Thats very interesting Rooster, I'd never heard of using epsom salt before. I may give it a try just to see. I'd never heard of flipping a battery upside down either Bob.

Matt :flags-texas:

[AMC RULES 36,945]

I thought it was bad to turn a battery upside down, doesn't acid leak everywhere?

I learn something new everyday here. :)

[tunahead72 2,341]

My father used to do this on his old 6 volt batteries on his tractor and in his VW bus.

Your dad had a VW bus? Cool! :handgestures-thumbup:

[kloe0699 12]

I thought it was bad to turn a battery upside down, doesn't acid leak everywhere?

I learn something new everyday here.

I learn alot on this site also Craig. And one thing related to this thread is you father knows more than you think! I wish he would have told me this years ago. I have a few dead batteries, will give it a try.

[Save Old Iron 1,563]

Rooster,

the chemistry of a new lead acid battery is simple - lead plates are clean and electrolyte is water and sulfur (sulfuric acid). When discharged, the sulfur leaves the sulfuric acid and gets deposited on the lead plates. The plates become coated and become less chemically active. Since the sulfuric acid has lost sulfur, it becomes weaker, more like water, and less chemic ally active - so the battery is overall less active. Charging dislodges the sulfur coating from the lead plates and returns the sulfur back into the water - making a stronger sulfuric acid. Just that simple. You're just pushing sulfur around. Remember - the right amount of mobile sulfur is key.

A 900 cca battery ???

Really? You couldn't find a bigger battery ?

A 900cca battery could be >95% dead and still start a 10 hp engine with ACR!

As long as a whole cell is not shorted, a nearly dead 900cca will turn easily over a 10hp in warm weather - NOOOO problem.

But if you insist, several options are available to those having funds to spend on "snake oil" additives for dead batteries.

Epsom salts - all this additive does is supply a small additional amount of missing sulfur and oxygen molecules into your depleted cells. Epsom salts do not CLEAN anything, the salts make the electrolyte a little more concentrated. The bad boy in this equation is the Magnesium in the salts. Maybe a chemist can tell us exactly where the Magnesium goes when the salt are dissociated, but I'm guessing we just polluted our electrolyte with a conductive metal deposit never meant to be in the cells.

"Cleaning" the lead plates is the forte' of the more expensive and exotic cousin of Epsom salt - EDTA - the chemical equivalent of sandblasting the lead plates. Sounds like we are now heading in the right direction, but the sulfur you blast off the grids is now chemically chelated (combined) with the EDTA and no longer can be easily dissolved back into the electrolyte. Remember, we need sulfur to be mobile to jump between water and lead plates to provide chemical activity in the cells. The EDTA additive has provided us with a clean(er) but only marginally better battery.

One other effect of EDTA addition is a chemical "sludge" precipitating off the plates and accumulating at the bottom of the battery. If you have a true starting type battery, there usually is a small space purposefully designed below the plates. This empty space allows for collection of precipitation without allowing an excessive accumulation between the plates. Accumulating deposits will cause physical deformation and eventual destruction of the plates.

Turning a battery upside down moves the sludge away from possibly cleaner areas on the lower edge of the lead plates and provides a temporary increase in electrical activity - until all the crap settles once again to the bottom of the cells, covering the same areas as before. A temporary gain at best. There may be some gain also due to mixing of the electrolyte that has become stratified - somewhat like old paint settling out in the can.

Enter the most promising solution - electronic desulfation. High amperage (70 - 80amps), extremely short duration (10 millisecond) repetitive pulses sent thru the battery to vaporize the thin interface where sulfur joins lead. The small pieces of sulfur then fall back into the electrolyte and rejoin the electrolyte where it belongs. If the desulfator is part of the lifelong maintenance of the battery, you will get maximum life from the battery. I currently have an original JD battery from 2002 which still starts a 17hp engine in warm weather. I may get the rest of this year from the battery but I don't expect much more. The key is the battery has been under constant trickle charge / desulfation for the last 5 - 6 years. I built this circuit for a friend who went off the grid years ago. I built it to his specs and gave it to him. Never thought twice about it until he told me how great it worked. I have a project planned at SOI U this fall to incorporate a similar circuit into a standard rectifier regulator circuit assembly. This will allow the battery to desulfated while the tractor is in use. Stay tuned.

I have taken some liberties in these explanations, but I believe we have covered some basic concepts which generate a better understanding of pitfalls and realistic expectations regarding additives.

Best advice I can give is

keep the battery charged at all times

do not let an uncharged battery sit for an extended period of time

recharge at the LOWEST charge rate possible

do not overcharge

desulfators ??? - yes - use them if you have them and use them thru the entire life of the battery

[Rooster 191]

I knew the smart guy would show up sooner or later!

Thanks for that explanation!

From all of that can I take that I may have "hurt" this battery?

I am of the opinion that what I did is definitely a god thing...maybe "how good" could be questioned, or maybe there is a better way.

But this battery would not start a 4 HP engine when I sat it outside and would not take a charge at all? Before I did this to it, I tried again and no luck!

WIth about $3.00 investment I have a useful battery out of yardd debris!

I will try it tonight on my Race engine...see if it will turn that over ?

Where do we get one of these desulfators?

Right now, I have 4 race mowers & 8 tractors...working on having an even dozen tractors and 8 other "custom" tractors...so in the next couple of years I will have 20 batteries that need maintained!

My plan as of now is to get one of the Schumacher $30, 2amp electronic charger/maintainers for each machine....maybe I am making the wrong investment?

[Rooster 191]

Rooster,

I have a project planned at SOI U this fall to incorporate a similar circuit into a standard rectifier regulator circuit assembly. This will allow the battery to desulfated while the tractor is in use. Stay tuned.

I definitely will be!

[fireman 1,021]

Before leaving for vacation this week, I went to our camper to check on something. Went to turn the lights on inside and got nothing. Opened up the plastic battery box, you know the kind the has a cover that goes over the outside edge of the box, and found it filled up to the top with water!. The water had shorted the battery across the terminals for at least 2 to 3 weeks because we had used the camper prior to that. I think somebody must have messed with it because I've had other campers before and had never had this happen. Any way I pulled out the battery and put it on my charger. Now my charger is this:

http://www.batterychargers.com/ProductDetail.aspx?ProductName=94026806ACP

and it tells you if the battery is bad or not and shows you the voltage and percentage of charge. The charger showed the voltage at 1.3 volts. I left it on the 12 amp setting overnight and in the morning it said "BAD BAT". Man was I pissed as the camper is brand new and the manufacturer date on the battery is Jan. 12. So I checked the voltage and after being on all night it was only at like 5 volts. I put it on again but the dropped the amps setting down to the 8 amp one and left it overnight again. The voltage came up to 9 volts but the charger still said the battery was bad. I then put it on the 2 amp setting and left it on for the whole weekend. Come Monday morning the battery charger showed it was done. I checked the voltage and it showed like 13.8 volts and 100%. I don't have a load tester for it but it sat for a week and I checked it again and the voltage stayed the same so I'm assuming it's still good. I don't know if charging it at a slower amp rating made the difference or not but it seemed to work in this case.

[Rooster 191]

Would be interesting to know if it was the low amps or the repeated charging?

[73-18 automatic 8]

Battery charger's work off of resistance when the battery is dead it has low resistance which means the charger will max out but if the battery is sulfated or over discharged the charger will shut off early. Ok so if you charge the dead battery slower (low amps) it will take a charge and not shut off early

[73-18 automatic 8]

Chrarger's can be funny sometimes. When a battery is overdischarged or ran below say 10 volts the charger has a hard time reading the battery. The charger will come on but may shut off early because of the quick change in state.

[Save Old Iron 1,563]

Agreed. The new breed of smart chargers have microcontroller circuits that will make decisions on the best way to address the only condition they can sense in the outside world - the VOLTAGE of the battery they are hooked up to. From that point on, the battery charger acts in a fashion that a software designer programs it to act.

My understanding is the logic goes something like this

measure the voltage at the battery

is it less than 10 volts ? if yes then apply a preset maximum charge rate to the battery (preset rate will protect the battery charger from overload and the user from excessively high current boiling over a possibly shorted battery).

charge at the maximum rate for x minutes (software designer picks what x minutes is)

read the battery voltage again

if the battery voltage rises a certain amount (again, picked by the software designer) - continue to charge

if the battery voltage fails to rise x amount in x minutes then shutdown the charger (or go into a trickle mode for safety) and display some sort of DEAD BATTERY message.

Not your grandfather's battery charger for sure. No longer will a charger just peg the ammeter and click the circuit breaker in and out all night to attempt to charge a dead battery. An understanding of how a lead cell battery operates will help you understand how new "smart" chargers operate and communicates with the outside world.

[Save Old Iron 1,563]

Would be interesting to know if it was the low amps or the repeated charging?

Some "smart" chargers will check their connection to the battery before they start pumping current to the battery. This check is done to prevent sparking at the battery terminals and is considered a safety feature when charging batteries in a marine environment. So if the battery voltage is too much below a cutff threshold, the charger just doesn't see the battery. Repeated attempts to charge the battery apparently raised the battery voltage enough to finally allow the charger to "kick in".

[73-18 automatic 8]

Sulfation adds resistance to a battery so some charger's will pick it up as a charged battery (lettting a battery sit for a long time builds sulfation) sulfation is when the acid absorbed in the plates is not returned to the electrolyte.