Great video, by the way. I rebuild batteries as a 2nd (semi-lucrative income), so I just have a couple of suggestions that you can do to improve your success rate. 1st (do a simple prebuild {pour out and filter original acid}, then using Baking Soda. You can use Tap {HOT} + Baking Soda mixed well and pour into each of the battery cells. This will remove almost all Sulfur buildup off Lead plates. After 15 minutes, pour out baking soda mix and rinse out the cells thoroughly. 2nd - Take filtered original acid, refill battery. Get Lead Acid Refill Bottle (at Advance Auto Parts) and top off battery level. To truly rebuild a battery to perfect, you need an Impulse Charger (fairly inexpensive). If not, then you can do the welder, but an older battery charger (the "Roll-a-round" style, which Harbor Freight still sells), will do the trick quite nicely! In 8 years of rebuilds, totaling almost 200 batteries, I've only had 5 fails. Hope this helps!

My dad talked about rejuvenating a dead battery and I never believed it until he did it several times at my gas station. He would take a dead battery and place it on charge and get it nice and warm. Then he would turn it over and allow the electrolyte to drain out. Next step, he would flush each cell several times which would help removed deposits on the bottom of the battery and help clean the plates. When it was flowing clean, per say, he would drain it and refill with new sulfuric acid and place the battery on charge. We never needed to purchase a battery for the purpose of giving a hot shot on a road call as we always had a reclaimed battery. The recharge was done with an old associated battery charger that was seen around may garages in the 60's and 70's. I wish I still owned it as it was kinda bullet proof and just kept on recharging batteries. I believe it was a light green case and it had a set of rubber wheels and a handle plus a hinged lid over the controls.

I learned from VGG that you gotta put your used batteries on boil for a few hours and that usually brings them around. Otherwise you gotta dispose of them safely by throwing them into the ocean for the electric eels.

The testing was great, will i ever do this probably not. But, what you have explained and showed as to how the batteries work are greatly appreciated. I have worked on mowers for people which had low charging systems and now i can actually explain why their charging systems need to be up to par.

I did 225 amps for 10 min then 1 hour rest. Did this for 5 cycles, brought the battery right back to life. Been using the battery for the past 6 months no issues. I think you need more amps and a little more time. i think 100 amps for 10 -15 minutes for 5 cycles would work good. You then need to trickle charge the battery at like 2 amps for like 16 hrs.

One way I have found to (maybe) get a stubborn battery to take a charge that a smart charger refuses to help is to hook up a fully charged battery in parallel with the problem battery for 10 to 30 minutes. Sometimes that's enough to get over the hump where your smart charger will take over and finish the job. Works for lithium Ion batteries too, but your connection time is measured in SECONDS not minutes.

I usually do 20 amp punch for a 15-minute procession. Let it sit for half an hour after each session, and I have restored 3 batteries so far!

I actually just did something like this not too long ago. I bought a used Escort and the battery was flat dead on it. Took it out and put the charger on it and it would only put out about 400 CCAs. Hit the jump start on it and cranked amps up to 30 for 10 minutes three times and charged it for a night after. The next morning, CCAs jumped to 725 and now, the Escort has no problem starting!

My favourite mechanic uploads again. Total is a good day.

Detailed and scientific explanations. Useful and useful content. Thank you

I remember in high school auto shop a battery exploded. Dude took the lead off the battery while the charger was still turned on. That battery flew up and hit the 2nd floor ceiling.

Experiments were smartly done. Thanks for this info.

I actually cringed, and leaned back in my chair as I watched this video. So very happy these didn't blow up.

1- I would have used a manual "Dumb" charger that has a multiple Amp settings instead of the welder . 2- When you get over 11 volts reading, you can use the smart charger for an extended period of time as you very likely can damage a perfectly restorable battery if you keep "zapping" it with the welder. 3- If you are going to use the load tester, you need to make sure that the battery is fully charged and has 12.6v+ otherwise the amperage reading will not be accurate. Thank you for your intelligent car videos.

That was very interesting. Project farm channel did a similar test few months ago and had similar results. I would use my welder in a pinch after seeing these two videos. Thanks!

Works really well with my 1100ah off-grid battery.If you desulfate with an overcharge your electrolyte levels should come back to right around normal if it did bring the battery back. sulfate turns back into acid your level should come backup and you shouldn't need acid. The plates on car batteries aren't thick enough. The desulfating is typically used on traction batteries built much more robust.

Great video. Very informative and easy to follow. Thank you😊

VERY INFORMATIVE! THANKS!! KEEP UP THE GOOD WORK.

You also can do things like gently tap the battery with a rubber mallet to try and break up some of those deposits. Also seen a guy gently rolling his battery down a grass slope, but gently. All these things are supposed to basically use physical movement to try and break up the sulfate... but obviously be careful because you don't want to break up the lead plates, they're made out of thin wires and are actually a grid not a continuous plate... and they're forms of lead that are very brittle and fall apart.

This is the second time seeing this on KZfaq. You went way deeper. Q1 - what if you drained electrolytes first, filled with distilled water only, did the cycles, replaced with acid? Q2 - what if you never introduced distilled water, but topped of with acid instead? Q3 - what if you drained avoid, and topped of with fresh clean acid? Before you hit it first time.

Nice video learned a lot of useful information. Thanks have a great day!

Great video. It is disappointing to see that none of the batteries were able to be resurrected but they did have a partial improvement. Thanks for making this!

I zapped two batteries last week and so far they are working good.

There are some chargers that actually have a desulfation mode, my old boss borrowed me his CTEK and it had a reconditioning mode that hits the battery at 15.8V and 1.5A to break those sulfate crystals.

about time someone did a welder test on batteries ,i always wanted to know

Blasting away when the battery is in a severe state of discharge just removes the sulfate mechanically and it is lost. Thus, you just prolong the nuisance of having to replace the battery until you are on the way to a wedding or some other important function. It is pretty common to cause an open circuit in some part of the internal rigging of the battery. Also of importance, that gas coming out of the battery contains hydrogen and it can combine with oxygen to "pop" which isn't actually a pop. It can blow the whole battery apart. When this happened to me, there was hot acid everywhere and my ears were still ringing for about 6 weeks... Bottom line, work an hour or two overtime on your job and then buy a new battery. Trust me, it only hurts until you do it and you are then on to the next adventure!

I don't have a welder, but I learned a lot about how batteries work.

Very informative. Thank you 👍

I also was not very succesfull using this same method. Used method once on a dead (11,69V) and I concluded if the voltage is not too far away you will have succes. No nerve too use the high amps like 75. Wet my pants, great video well explained, thanks

My uncle does this yearly on his batteries as maintenance, given that I've seen some battery brands I've never heard of with some old stickers, I'd say it works in that way. Blast off all the old crystals for the year, I'd buy a cheap IGBT stick welder for that.

Thanks for taking the time to ahare.

Smart and well explained!! Thank you bro!! My question- what will happen if I don’t have that antique welder, and my welder have only AC output?

Thank you for this amazing info! ❤

Thanks for the big work for us.

might note that the electrolite is a mixture of water and acid. the cells are low because the water has evaporated leaving a stronger acid solution. when you let the acid mixture boil out while charging you are loosing acid so if you add more water you are getting a weaker acid concentration.

Thank you. Very informative video.

Thanks for the info 😊

With the voltage readings taken, how are any negative readings recorded? All the positive voltage readings have a negative sign 😮. Thanks for the technical information information. All the best.

Great info dr steve

I used to be a battery replacement installer. Putting an arc welder anywhere near a battery is an ignorant endeavor. I have seen customers come into the shop with batteries that had the tops blown off! The battery acid can destroy cotton clothing, and it can burn you!

It’s worth a try anyway 😊 Thanks 🙏

Once you got the battery #2 to 11.something, you could have put it back on the smart charger, and probably got it back by restarting over & over for a few days..... Seems like it would have taken a charge at that point..... It takes TIME for some of this to happen.... You need the Sulphur crystals to go back into the acid suspension, in the sulphuric acid..... Ideally, you'd be at a very gentle boil, where there would be bubbling, if you looked in the holes, but acid wouldn't be gushing out.... as the acid gushes out, you are losing some of your sulphuric acid.... thus, when you add more distilled water, you have a weaker acid solution there, which won't work as good inside the battery....

Project Farm had done this as well, interesting results

Good work 👍

I feel that after blasting the crystals: draining them, flushing with disntilled water, and then rebalancing the batteries with new sodium sulfate electrolyte solution would greatly restore the capacity after desulfation, instead of using the old polluted water. I would consider that a true refresh, maybe not 100%, but maybe you can get 90% true capacity back. You should try sodium sulfate refresh and test it out, would give you a pt2 for this video.

A De-Sulfator that works slowly without heating the battery up is probably also a bit better for the battery than the welder that can boil the water.

Great Idea and great video.... there is something i am still wondering. and would hope you could test. First zap the battery with 35 amps for 5 minutes to bring it to around 8 volts. (if it is below... of course :-) Then SLOWLY Charge it over night with a normal charger! Then once again two cycles of 35 amps on the already "fully charged" batteries. Then test again. Or way number two. First zap them the way you did and afterwards charge them with a normal charger before testing them.

I don't think you want more sulfuric acid in there if the low level is only due to evaporation. The acid in there already is thus extra concentrated so the plain water will return it to its correct strength. Also aren't the lead plates spongy to increase the contact area for higher amperage?

I find that after the desulfation process, putting the battery on a very low (anywhere b/w 1 or 2 amps) trickle charge for a long time (24 hours or even sometimes 48) works well at getting it up to full voltage; typically around 12.7 volts. Also, a series of discharge/charge cycles can help in building up the mA-hr. capacity of the battery. It can be a long process sometimes to rejuvenate a weak battery, depending on how old it is and how badly sulfated.

A few comments from my experience and chemistry I learned in school: The acidity of the electrolyte changes during charging and discharging. The water evaporates but the acid remains so its concentration also varies due to evaporation. Because of the excessive concentration, Sulphur crystals precipitate on plates. So the electrolyte concentration between cells can vary widely, especially on unused batteries. So, a good restauration (presuming the plates are not bent beyond hope) would require: -Emptying the battery in a safe container. -cleaning the cells from precipitation as good as possible with distilled water and a basic solution (baking soda). -charging (more like boiling) a battery with distilled water for a couple of times, water will dissolve all the remaining crystals. Or better said, crystals will dissolve in water due to difference in concentration and heat. Check the acidity of the distilled water, it should increase. -Safely discard the resulting solution, it is basically a mild sulphuric acid now. -replace back the electrolyte with correct concentration to the recommended level. I would probably use new electrolyte if I wasn't a cheapskate. For maintenance: -top up to recommended level with distilled water in order to rebalance the concentration equilibrium. Toping up with electrolyte will cause the Sulphur crystals to precipitate. -Keep the battery connected to a smart charger, one that can provide trickle charging I have a 10yo battery that I restored back to 90% rated CCA.

Your like a battery wizard bro!

First off, I'd be wearing a full face shield when doing this, not just goggles. Over 40 years ago I learned how to work on cars from helping my older brother. Once when I was still young he needed to jump start a truck and didn't have good jumper cables handy, so he used thick welder cables like this. My job was to hold the cable's plug ends onto the good battery's terminals while he turned the key. I don't think it worked, but it made me think how a disastrous thing to do would probably be to connect welder cables to a battery and then turn the welder on. I figured the battery would just explode immediately! Neat to finally see what actually happens!

Remember if the battery blows up, don't forget to look away. If you do a real good job of it, the entire top of the battery blows off in your face. I was close to Sears at the time so it wasn't a long walk to get a new battery.

Ive seen batteries blow up man so please be careful with this. One time in a small Jhon Deere 190 excavtor there was a hairline crack in the battery from people hammering the terminal on. Gas escaped and a bad connection caused a spark igniting the gas escaping from the battery while I hit the key and it blew the end out of the battery. Sounds like a shotgun going off. My brother was headed back around to check the connection when it blew up almost in his face. Another time I saw a mechanic mistakenly hook up 24V to a dead 12V battery so we could unload a track loader and free up a trailer. That battery instantly blew up one cold morning as he hooked it up to 24V. Luckily he had the habit of turning his face when hooking up battery cables. Many folks haven't seen them blow the side out yet so do be careful.

Thanks for this experiment! Conclusion as far as i'm concerned, if a battery is this bad, just go and buy a new one.

Well that was educational... I remember the time I blew the top off a battery... yep, separated the entire top plastic section from the rest of the battery, sounded like a rifle shot too when it went off... luckily nobody was standing over the battery at the time... or they would have been toast

I think that video is pretty nifty I never had a clue as to what actually makes a battery degrade I think that was the bomb 💣 nice 👌 thanx

Distilled water can actually contain more minerals then regular water or tap water due to the concentration caused by condensation in the still during distillation. If you want water free of minerals you need to you “demineralised water”.

Useful information,

Heads up! Not all stick welders run the stick welder on positive. In fact my hf stick welder runs reverse polarity. I just did this project and reversed charged my battery. Crazy

one of the methods of yesteryear was to do this with frozen water/sewer metal pipes.. yes, this was before plastic piping got a foothold..

Excellent Excellent Excellent! clarity. many thanks for sharing your knowledge...DVD:)

Interesting, with good information. That said, I'm gonna buy a new battery.

After watching a bunch of videos claiming batteries can be restored I am convinced that it's best to take dead batteries down and buy new ones. It's cheaper, faster, less hassle and it works.

I bought a cheap 2nd hand dc arc welder just to try this after the Uncle Tony video. I'd heard of it before but wasn't encouraged to try it before then, but I've since tried it 3 times and it simply has not worked for me and I subsequently deem it not worth the effort vs the even significant price of a new battery.

Came for the "hey hey hey", stayed for the explosions

Question - what voltage is the welder outputting given the 30 amp setting? I've seen a number of these videos, but info only on amperage, not voltage...

How much internal resistance and capacity loss can your application take? We run our fence energisers on decades old car batteries. They only take a few (25~100)milliAmps.

Thank you.

I agree with you on the distilled water part, but I pretty much doubt dealers have it on hand. Right out of the hose I’m sure…

what voltage is the welder output? adding epson salts might help the welder.

Solid video 👍... I've done something similar & have a $50 Walmart Value battery still going strong @ approx. 6 years😄💪

Yes you can aggressively remove hard sulfate from the plates using a dc welder. Done it many times.

Fun to watch and learn 😅

If you get the muck of the plates its in the acid/batterywater. Change the acid/batterywater to get rid of the muck in the system.

Nice. Thanks.

Great video

Once you've kicked a battery up to around 11v with the welder can a smart charger work on it? My trickle wouldn't connect to sub 10 volts but will see it if it's over 10.

Keep in mind it is now 2023 and car batteries have been around for over 100 years. Since back then trying to revive batteries, so the when the say bulk charge at max of 30 amps its cause its tried tested and proven method. I have tried to revive numerous batteries.... and only 2 out of some 20 plus came back to life...temporarily. With these lead acid batteries best thing to do is go out and get new. you will waste more money by wasting time even if you do get one revived for short while, you will have to replace it sooner than you think. especially newer cars, more and more new cars you have to reprogram components each time the battery comes out. though i solved that problem connecting a small 12v battery to vehicle battery cables before removing them from battery being replaced. as long as the small battery is connected you wont loose programing.

Thank you very much

Wonder why the Lexus' battery was so low to start with. Was it discharged intentionally or does the charging system need checking? Great video! I would've used ear plugs also, just in case one of the batteries blew up!!!

thank you , awesome video , i like that you are very funny.. by the way i like the music at the end of the video , what is the name of that song or music.

"Lose subscribers due to reality" --- You are really funny!!! Very enjoyable, good measurement of not just voltage but amps as well. Well done!

You're doing this without any consideration at all of the electrolyte levels is essentially flying blind. Get a hydrometer and check/adjust the electrolyte and that might make all the difference. Also, I've seen many people dump all the acid out after some signficant agitation, collecting the acid and filtering all the debris that comes out with it, put the acid back in and this can make a big difference. Often the debris is a dead short between the plates.

I use all batteries in my camper where I don't need cold drinking amps. I have batteries 10 years old that still work PERFECT for small devices.

Resistance of the load will determine amps here. I guess a dead battery might be surprisingly low resistance, but it would be interesting to measure actual current (and voltage) while charging. I kind of wounder if hitting them with some A/C wouldn't help to remove the sulfate... then charge.

I had an old car battery blow up right in front of my face as a teenager, simply by boosting it correctly just as I moved the cable for a better connection!!! It went off like a shotgun, thankfully my dad and I didn't get hurt....I've worked at car lots and automotive industry, I've boosted thousands of vehicles in that time but a little piece inside me cringes still, when I boost a car to this day. My Dad was a mechanic and said it was from built up hydrogen gas in old battery. Thankfully we were ok, just a tshirt with acid holes was worst damage. My husband is a mechanic also and he also had a car battery blow up but he got lots of the acid in his face when it went off like a shotgun. He said he left his eyes closed and ran for the hose to rinse himself off. He also says he suffers from "battery PTSD" like me. Moral of the story....be careful with old batteries!!!! My

Can you use this method for gel batteries

Did you checked electrolite density?

My smart charger has a good "manual" option for really sad batteries that are normally not even recognized as a battery even connected to it, although I did almost have a problem that was my fault, from not keeping an eye on the big battery I was trying to recover, and it became too hot to touch 😮 but my rusty 50 year old 2amp charger is good for just leaving on for a few weeks 😅

What about the recondition mode on a smart charger? What does it do to condition a battery? Essentially how does it work?

There are probably all kinds of reasons and local/EPA regulations that should prevent you form dumping electrolyte down a drain or on the ground because of the lead contamination issues. Same concern for remaining in a closed place with boiling batteries!

Why aren’t the cell materials available for rebuilding the battery? You can remove the top and rebuild each cell. It’s done all the time in other countries. Why not this one? Everything has to do with money and not the needs of people.

I always find the older chargers that are not smart chargers. ... They're still around.. I got four or five of them. . small ones all the way up to 200 plus amps,...👍👍👍

What was the voltage (from the welder) during the tests?

Cool test, but in my opinion, trying to charge each of these batteries with a regular charger after filling with water and using those results as the baseline for further improvements would have been a much better test since it would eliminate the question of whether the welder actually repaired the battery or just somewhat recharged it. I suspect you probably could have gotten very similar if not better results by just recharging the batteries with a normal charger, but since you didn't try it, we won't know. Also, keep in mind that it takes a minimum of several HOURS to recharge a deeply discharged lead acid battery no matter how much power is available, so you may have gotten better results by recharging those batteries overnight with a charger after using the welder because you didn't fully charge them in the few minutes you had the welder connected.

Would a short blast of reverse polarity help shed those sulphate crystals first, or would it ruin the battery?

do you use a-c or d-c welder output

I BOUGHT A BATTERY OUT OF THE JUNK YARD THE OTHER DAY IT HAD 12.5 V READIND ON IT BROUGHT IT HOME WILL NOT START MY CAR SO I GOT A DONER BATTERY JUMP STARTED IT DROVE IT FOR SOME TIME AND STILL DEAD IS THERE ANY THING I CAN DO TO RESTORE THANKS RATCHETS,,,, I LOVE YOUR OTHER VIDEO ON SPRAY PAINTINT THE CAR

I used to do this with an older diehard charger that had a 75A start option. Id remove the battery from the car and go at it for a few minutes resetting the charger as it hit the safety. ive only had a few batteries not come back to life from that.