How to PROPERLY Recover and Recondition a Sulfated Battery

I have an updated video available here where I use different equipment.

There are many 'snake oil' salesmen out there who would like you to purchase their product. Do not be fooled. There is no magic solution or product to recover an old battery, the only complete solution is to purchase a new one. However you can get more life out of an old sulfated battery with the proper recovery technique that anyone can perform with very basic equipment. This video shows you how to do it.

Tired of terrible battery chargers? Try this one! You'll need to put a cable and clamps onto it (cut apart a jumper cable) but after trying one of these you'll realize that ordinary consumer style battery chargers are absolute junk. This does NOT desulfate. Powermax sells similar chargers but they do not output the current advertised and are constructed cheaper.

Need a DC current clamp meter? Save vs purchasing an expensive Fluke meter.

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I cannot guarantee against unauthorized modifications of this information or improper use of this information. I assume no liability for property damage or injury incurred as a result of any of the information contained in this video. Be sure to read and follow all safety instructions for any equipment seen or implied in this video, and use safe practicies when working with potentially dangerous equipment. No information contained in this video shall create any express or implied warranty or guarantee. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user.

[evanmayer]

good grief... to think that a 10 year old video contains a far higher amount of relevant and practical information than I can find on any modern content... this right here is what youtube is for. Thank you.

[BD-dskg]

I have lived off-grid for 15 years and have been a ham operator for 45 years. THIS DUDE KNOWS WHAT HE'S TALKING ABOUT! The rest are hucksters! I have used an Infinitum desulphator (this is not an ad, BTW, there are other brands as well) for the last 7 years and my average system voltage has gone from 23.9v to 24.8v after about a year's use. I believe adding a desulphator is good maintenance, but it does not restore batteries. Using a desulphator to keep a battery in good condition is not magic. Remember, what he said, taking good care of a battery is what it's all about, not free lunch...This is a first-rate post! Thanks!

[pudco]

Not only is this instructive, it's informative and explanatory. This is what the internet needs!!! I've been looking this sort of thing up for about an hour and after several youtube videos, this one came up, and I wanted to say Kudos and thanks for this informative video! I like when someone explains how and why something works. Leads to better understanding.

[brianroberts]

" You can patent anything. It doesn't have to work. ""
Greatest comment ever.
What a great video. I learned A LOT. Thanks.

[knurlgnar]

Followup for anyone interested: I still use this battery today 5 years later for various purposes. It has about 50% of its expected capacity and about 200% of the normal series resistance. It is still useful to this day which is better than being thrown out, even if it isn't as good as a brand new one.

[Ed_Aylward]

Thank you for taking the time out of your day to educate us. Being that we only have about 32, 000 days, or 960 months of life, if we live to be 80 years old, time is priceless.

[DanBrown]

This method works 100%! Picked up a use NIB Back UPS and when I opened it I discovered it had been unopened for 16 years. The 12v 5 mAh SLA was totally dead. Watched this video then I proceeded to fill all the cells (all were completely dry) and connect it to my bench power supply pushing it @16v. For the first 24 hours it was only drawing about 1 mA and had only come up to about 6v, at the end of the 2nd day it'd come up to 10.6v but was still only drawing 1 mA and it stayed there for 48 hours, I was beginning to doubt that this battery was salvageable. I noticed it the middle of the 4th day that it was drawing 3 mA and had come up to 11.9v (there might be something to this!) 4 hours later it was sitting @13v and as it stands now I'm draining it down to 10.5v with a turn signal bulb and it's been running for nearly 30 minutes. Amazing that I could bring a 16 year old battery back to life with this process.

[sometimesfirstsometimeslas]

This UT brought back fond memories. My uncle owned a small automotive repair shop. I worked there during a few summers while in HS. I noticed he had a bank of batteries that he had on chargers (all were dumb at this time. LOL). I asked him what he was doing with all these old customer batteries. He said he was reconditions them. I thought it odd at the time, but he seemed pretty confident that it work for some. I guess he was right. I learned a lot about cars. If you maintain the battery, rubber hoses, belts, oil, coolant, and tires even long ago most car almost never stranded one the road. And true today.

[mewantbrains]

Just restored 2 100AH scrap yard batteries Using a 20V 90W laptop charger and a 65A load using a similar method to this

It took me 2 days to restore instead of 2 weeks just by changing the voltage and load

Initially after charging with a smart charger and both batteries linked in parallel they would run the load for about 20 sec before the inverter shut down

After recovery they ran the load for about 2 hours

I let the battery voltage go up to around 15-17 volts and left it at that voltage with the laptop charger switched on for about 20 min then disconnected the charger and let it rest for an hour then drain it with the inverter then recharge with a smart charger then overcharge with the laptop charger

I repeated those steps about 4 times a day for 2 days and now they are in service powering my off grid system

[vicromono]

This tutorial is packed with the good information and zero bad advice. As a simple safety tip it should be pointed out that flooded lead acid batteries expel flammable gasses (hydrogen and oxygen) during the charging process and should be performed in a well ventilated space. Hydrogen is a lighter than air gas so common sense would say "don't do this in a closet or under a non-ventilated hood. But hey, who needs eyebrows. My old man used to tip them upside down, rinse them out, smack them with a dead blow hammer a couple of times and refill with clean acid solution. I could see the old sulfur and crud poor out and it usually helped on old farm tractor batteries. The main trick is getting the crud (sulfates) to slough off of the plates as he clearly explained in the video.

[thomaskelly]

Well done young man! Years ago I used a similar method to restore thousands of dollars worth of batteries in building inverting systems. The charger I used was so old it actually had tubes in it!

[onetongwa]

Finally some more videos on stuff I have been doing forever. You can restore lead acid batteries and you can’t restore lithium batteries easily at home. The companies want you to spend money and keep buying more batteries or new technology. I love maintaining and restoring anything I have. Lead acid batteries are perfect for home base solar storage And I easily restore lead acid batteries with Raw solar power without the smart solar charger. I would use lithium for lighter transportation needs. People need to know the truth.

[MMSDK]

I have restored many car batteries using the old charger method and for the most part, maybe 7 out of 10, would all recover. Some were old truck batteries which take a lot longer to stabilise, but most get there in the end. 

My reason for needing these old batteries as a kid - C.B Radio, until i was old enough to buy a stable rectified and regulated PSU. I did miss the bubbling sound beside my bed though...lol.

Some good info for cycling the batteries you have given. Info I will no doubt benefit from one day. Top vid mate.

[fenderbassix]

Understanding the physical chemistry is slightly useful and this video is good for this. After 50 years of car battery life cycle experiments I concur with the approach taken here.  Cracking that sulphate layer is needed, but not so hot that the plate loses useful material underneath. That's why a pulse charger isn't so good: the plate reforming doesn't work so well with high currents so you lose capacity. 

[ariagrippasboulevards]

Probably the only legitimate video on the subject. Everybody else on youtube nowadays is in love with epsom salts and trickle chargers.

[spyrosbellos]

Thank you for this tutorial Knurlgnar
I tested my car battery from my car (varta d59) with a conductance tester that calculates the amps the battery puts out based on its internal resistance, it tested at 388A out of 540a. I made some tiny 1mm holes on the top and used a syringe to add a bit of distilled water in it each cell, all of them had the plates covered but each one was at a different level. I then put it in an equalising charge at 16 volts for 24 hours, then i did a discharge with an h4 headlight bulb and after recharging it it went to 432A. I just finished the second discharge cycle and i am waiting for it to charge to test again.

[euregmf]

Thanks so much for the information! This is a fantastic tutorial as are your other videos on reconditioning batteries. I was struggling with getting severely imbalanced SLA Group 4D batteries back to health, (they were only 6 months old and in light cycle use) and your videos pointed me in the correct direction.

What I found, and what helped me: The key is to not stop at the voltage of the 20 hour rate, but make sure the resting voltage after discharge is at the 20 hour rate. I had tried to recondition stopping at the 20 hour rate (10.5 volts in my case) but that did not work. my batteries were not improving. I tried slow recharge with 2 ohm resistor for a week, recharge at 1 volt over the upper limit (condition equalization charge) for 24 hours, charge at 14.8 volts for 2 days, 40 amps for 10 hours, nothing worked. Then I thought about what you said about referencing the spec sheet in one of your reconditioning videos and getting amps through the battery - I'm theoretically putting a ton of amps back into the battery, its not holding the charge - it wasn't even going to heat, it was just doing nothing..., so maybe I'm not discharging enough 10.5 and stopping is just not enough? That was the case. After complete discharge cycles so my resting voltage was at the 20 hour rate spec, the batteries started to improve with the reconditioning you outline.

I had 10 out of 26 Group 4D batteries like this, so far I've got 4 recovering, 2 back in service. I read up on how imbalances that ultimately lead to sulfation like this can happen, turns out it is manufacturing defects! Improper ratios of the lead + active materials (tin/calcium/etc) during manufacturing causes the internal cells to become imbalanced when lightly discharged and slowly recharged. (however the manufacturer of these batteries will not refund me or give me replacements, soooo I won't ever purchase from them again) but your methodology works to bring them back into balance and back into service. I just hope I don't have to do this too often, because it is ridiculously time consuming :)

Thanks for your videos! Useful and accurate information that solved my problem!

[bennyh]

After watching a few years back I have revived a few batteries using this method. What I use rather then old charger is just a small 10w panel and controller hooked up to battery until it holds 12.5 then I cycle it...after about 4-5 cycles I can usually use it again to start a car. It takes quite a few weeks sometimes longer but doesn’t cost anything to leave them hooked up on a panel.

[Deceptive]

Excellent honest video. Thank you for taking the time to make it! Exactly the no snake-oil engineering approach I was searching for.

[patrickbodine]

$60 batteries have gone along with the dodo bird.