DIY Battery Spot Welder - Update & Demonstration

I've created another video go explain my DIY spot welder and to cover a lot of the most asked questions I've been getting on previous videos and dispelling solve of the myths surrounding this method of spot welding.
*Nickel Strips*
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www.ebay.co.uk...
*Solenoid Relay*
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*Choc Block (Electrical Connector)*
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*Copper Nails*
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*Heavy Gauge Cable*
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*Momentary Switch*
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My Website: kevindark.co.uk
Evolve Battery Upgrade: kevindark.co.uk...

[@The-Advent-Sabre]

You sir have just built a time machine! Here's why. Surfing my way through KZbin, this very video comes into play... within minutes i'm going back in time watching my dear old Granddad build something almost identical. He was an electrical engineer working for the Fawley Power Station. He would make battery packs for stuff he needed at work (No I know they weren't lithium modern stuff) but he also used a much bigger one to spot weld panels for heat shielding. SO on this particular day I was with him in his workshop, when suddenly he exclaimed to himself he needed to spot weld the panel seams.. I had no clue of course what the hell he was talking about as I was only 10. I then, with great interest watched him MacGyver two huge truck batteries with wires and big copper prongs, a few other bits and bobs bolted here and there and within about an hour he was spot welding panels together. This video just sent me back to a fond memory of my Granddad, and his wisdom and sheer ingenuity and resourcefulness. Thank you.

[@julescircuits845]

I guarantee he had some sort of safety cut out, be it a breaker/fuse or the cables he used being rated as a fuse point or something else, no way an electrical engineer would leave out safety factors when dealing with stupid high currents.... I'm curious as to what exact details you remember but yeah, its a very long time ago :)

[@The-Advent-Sabre]

@@julescircuits845 oh I don't doubt that too for one second. But at the age I was I wouldn't have known.

[@Jaze2022]

@@julescircuits845 only engineers fresh out of school obsese over safety. With experience, you realize what would naturally break and act as a safety cut off. Practical experience > theory crafting

[@davidmg1925]

You talk of the Fawley Power Station. As story has it my family owned the land that the Fawley Oil Terminal is now on...... whether that's the same thing. My Grandmother always maintained she had been diddled out of a significant fortune by a wicked Uncle: re the compulsary purchase of the land. Later researches showed that My Grandmother had relatives who undoubly owned a farm in the area, that much is quite true. Other than that, Im told, the story is fiction. Weve all enjoyed dreaming of what might have been, had the story been bourn in fact. Apologies for the gate crashing.

[@The-Advent-Sabre]

@@davidmg1925 Wow that was interesting, I live on the doorstep, literally, of the Esso refinery. I have lived in it's shadow almost all my life. My mum worked there years ago too. But heres the thing.... I've heard your story before! My Granddad, the very same one in my comment, said the land had been bought from people years ago, and probably didn't realise what their land was worth. Now i'm not suggesting for one minute that this makes it fact or that either story are connected... just a funny coincidence maybe? But none the less... interesting.

[@JerrySmiler1968]

I would just like to thank you. I was given an old ebike that would not charge. The cells had been left for years and had discharged beyond repair. To get a new battery would have cost me nearly £500. I watched a couple of KZbin videos including yours. I purchased new cells for just over £100 and made this spot welder. Today I set about dismantling and rebuilding the battery pack. Hey presto I now have a working bike. Thanks again.

[@darkkevind]

That's awesome! You're welcome! 👍

[@adriang6373]

I was about to buy a spot welder from China when I found this video, instead of spending £150 I built one of these using a spare car battery and other bits sitting in my garage. Total cost was about £30 and it works perfectly :-). My battery is a Ford OEM brand rated at 700CCA and i bought a 500A solenoid (same as the heavy duty one in the link). I tried .3mm nickel strip but it was a bit too thick, 0.15mm works perfectly and gives good, strong welds. Thanks for sharing :-).

[@darkkevind]

Adrian Guandalini nice! Be awesome to see it?

[@adriang6373]

I'll tidy up the cabling and post some pics soon. Not sure if you mentioned it ion the video but is this setup suitable for welding NiMH and NiCD cells?

[@darkkevind]

Adrian Guandalini yes, fine for any cells in this form factor.

[@adriang6373]

darkkevind I've built a few drill packs but my old 700cca battery seems to have died. I didn't hear any pop or anything but the weld arc became weak and the battery now only measures at 10v and won't respond to the charger so I'm guessing one of the cells has died (it was an old battery anyway). Is the BulletBatt you're using in the video still holding up? I can get one delivered for about £33, I can also get a similar spec Lion branded battery for the same price. Cheers

[@darkkevind]

Adrian Guandalini you've let the voltage run too low 😣 I have a little charger sitting on top of my battery that I connect to top back up after a hundred or so welds... With the higher voltage you get a decent amount of current. I'm still using the battery in this video, yeah, it's holding up very well 👍

[@bobcoburn5238]

Wasn't gonna make my own batteries because I couldn't be arsed soldering and couldn't afford a welder. Thanks to this video I think I'll give battery building a go as this seems pretty simple and cheap. Thanks man.

[@darkkevind]

You're welcome mate 👍🏼

[@phoobar9640]

I used the battery out of my car and an old motorcycle solenoid. It literally took 15 minutes to build. Mine's not as clean looking as yours, but it works. Good stuff.

[@darkkevind]

Nice one 👍

[@robz8989]

As long as it works that's all that matters I've got all my bits hanging 😂🤦‍♂️

[@viktorspeiser8591]

Thank you man, I was on the edge of buying one for a fortune, now I am making a parts list! Wonderfull work, great explanation. Not the fist video of your's I have seen, but this earnt my sub.

[@darkkevind]

Glad I could help! Thanks for the sub 👍

[@acmehighperformance2826]

i love the job youve done. im copying it to lern the skill now. i have a tip for ya. im a mechanic. the relay may eventually fail and one of the failure modes is thermal runaway. on my nearly identical system ill build tomorrow ill put a 5.00 dorman 140a fuse between the battery and relay. those things save me on truck systems often behind a relay. cheers and thank you. i did subscribe!

[@JesusChrist-sx1lf]

But the battery in this case have a 330A discharge peak, isn't a 140A a bit too small? Or how had it worked out for you?

[@handyhippie6548]

i made one of these from a 230cca. mower battery, a ford starter solenoid, a 4 ga. battery cable, a momentary push button, a plastic connector block like he uses, and 10ga. single strand copper wire for the contact points. all of the parts except the connector block were used and i had on hand, so total cost for me was about $10 for the connector block with shipping. it works great, with no issues, and i've been using it for over a year. this is the best design i've ever seen. i just quickly tap the button like he does, and presto! a functional weld.

[@darkkevind]

Hey thanks! I'm glad it works for you 👍🏼👍🏼

[@JesusChrist-sx1lf]

How much discharge current did the 230cca battery have? 200A or more for example?

[@alapon77]

This worked out very well for me, THANK YOU. Believe it or not, 2 of the 3 solenoids I tried out, didn't even work, so definitely make sure those are working before giving up. What's really important that I would add here is that you have to have the terminal connectors clamped down very TIGHTLY, otherwise the solenoid will seize (not permanently). A lot of us are comfortable using vice clamps but BE CAREFUL - because if you have two (oppositely charged) metal vice clamps sticking up in the air next to each other, that's an opportunity to short the battery while un-clamping and get the $#!+ shocked out of you. Also there is some chatter about using a timer relay switch. Don't bother. The quick tap is all you need as long as the CCA isn't too high (mine is 340). I've also learned that arc-ing is a common problem, resulting in burning through the nickel. This is usually because there is a gap or some 'air' beneath the strip. Two fixes for this is to make sure that your nickel strips are perfectly flattened and to put extra pressure on the offending lead.

[@laurabarnes3295]

Am using a battery from generator is it good 12v 7a

[@laurabarnes3295]

Works but the nickel dosent stick to the battery

[@handyhippie6548]

this is the simplest, most effective spot welder, and explanation video of how it works, i've seen. good job, and thank you.

[@darkkevind]

Thank you! 👍🏼

[@handyhippie6548]

@@darkkevind something for you to think about, a fender mounted starter solenoid from an older ford auto, or from a large riding mower, would be able to handle the amps no problem. auto starters pull 2-300 amps regularly.

[@mp180170]

You have explained everything perfectly I’m a trained electrician I love the spot welder kind regards liked and subbed

[@darkkevind]

Awesome! Thanks! :D

[@DJBelbe]

Love U man!!! Just gave this a try this eve with a 19€ bike selenoid, half dead pickup truck battery and junkyard cables and switch! Had a dead Dewalt battery lying around for ages with 3 new cells waiting to replace the fryed ones cos a spot welder costs a fortune! Well, with 30€ and your blessed genious I saved a 120€ battery in a single eve. Jollyest hollidays friend!

[@darkkevind]

Excellent! You're very welcome 👍🏼

[@powerbatterychannel4315]

I suppose, this is the best and the most reliable solution I have ever seen. Great job!

[@darkkevind]

Power Battery Channel thanks! 😁

[@eltorolatinoify]

This looks like it's the easiest fastest way to do it and you don't have to buy a bunch of stuff that could go wrong

[@junexjeyesmallbrain3477]

you said

[@Noxoreos]

@@eltorolatinoify Except that this whole setup can very much go wrong, because there is no safety mechanism included at all, like e.g. against a permanent dead short, when the relay wears out over time.

[@inso5078]

@@Noxoreos Nothing very bad would happen. Nickel strip would just break and that's it.

[@richardingle7540]

You sir ...are a bloody genius and true to British inventors of the past ...just ordered all this on Amazon...I have so many projects waiting for a welder which are to expensive and yours is so cheap and easy to build ...thank you from me and all the happiness my projects will bring now i can make the packs 😀👍

[@darkkevind]

I'm very happy to be able to help you out mate 👍🏻

[@richardingle7540]

@@darkkevind you really have , thanks for adding all the links to ...makes it realky easy to get it all so cheers .. 👍

[@NJmalibu313]

Thank you for explaining this man! Im learning more about this stuff everyday, and wanting to make a alternator motor ebike/cycle using a ford 3g alternator (130amps) that ive had laying around for years. Ive got experience building 4 stroke gas motors and bikes (welder by trade), but wanting to get into electric power. Im wanting to build everything including battery, and found your video here. Thank you for going over everything for electric dummies like myself. I have an understanding of starter solenoids from being a backyard mechanic, so this makes perfect sense. Ive even used a spot welder over the years being a welder, but never anything this small. Awesome!

[@alan6708]

Massive thankyou to you pal ive just made a spot welder off your idea and saved pounds just when i couldnt afford it, joys of lockdown, thanks..

[@darkkevind]

You're very welcome my friend! 👍🏼

[@alan6708]

@@darkkevind your a star, thank you.

[@thumperman8490]

Great video and well done. To get more accurate welds, you could program the time the welder is running by fitting simple timer to the welder. I was thinking of a 555 timer ( cheap as chips ) programmed for various mSec settings of welding. The timer switches a beefy transistor (say a 2N3055) that activates the relay. You would have to play around with the welding times to find the optimum settings for the various welds you encounter. It would take the 'stab the switch and hope' out of the current configuration. Stay safe out there.

[@thomasnewbery7449]

You can use a potentiometer and capacitor in the 555's circuit with values which would cause the astable (one-shot) range to be from a millisecond or two to, say, 250 milliseconds. Set and forget or use the adjustment of the pot to give you more/less time for a heavier/lighter weld. Wouldn't cost but a few bucks/pounds/yuan/lira/baht/pesos and would "fire" independantly of the 12 V source voltage by operating on it's own 9V battery....... ! Would fit easily into a cigarette package-sized box.

[@julescircuits845]

This is the safer design compared to the risky meltdown device described in the video... good thinking....

[@szentmihalyiautodiagnosztika]

Your DIY is the most convincing spot welder tutorial on youtube ( I have not found anything better and easier to make). I am still waiting for 4 weeks to crate a suitable one. I have tired with a 45Ahm car battery but the amperage was too much, I have also tried with a motobike battery 12v, 5 Ahm and that welding was quite poor. Now I am waiting for a higher amperage motobike battey ( about 7-10 Ahm). I am about to make an e-bike battery pack for my Bosch 36V bike and can`t wait to have it ready in the meantime gathering old laptop batteries.

[@darkkevind]

Szentmihalyi Autodiagnosztika it's not the AH you want to worry about, it's the CCA amperage discharge capability. About 300A is the sweet spot that I've found...

[@szentmihalyiautodiagnosztika]

Darkkevind actually I meant the CCA discharge. Thanks again!

[@k-member]

Great! Thanks man! Simpliest spot welder of entire internet!

[@jeliason753]

Thanks for the video! I built one after studying your design and must say there is a learning curve for applying the welds effectively. I built a 7s26p battery pack using 3.7 V Li-ion batteries. I will say that pure nickel tabs are much better than the nickel plated variety. The plated tin seems to burn through easier. I twisted some approx. 1 mm diameter copper wire together in two strands for each electrode. I found that filing the electrode tips clean regularly while welding helped them not to stick or burn through. I borrowed the 12 V battery from one of our cars for the power source. I charged it with a float charger in between sessions. Your videos were very helpful, so thanks again!

[@darkkevind]

J Eliason that's awesome! Yes! There is definitely a learning curve! 😕 I too have find that cleaning/sanding/filing the electrodes and making sure they have a nice point in them helps to make clean welds. Glad you could make one from my video 😉

[@laurabarnes3295]

Please mine doesn't stick to the battery what could be the issue

[@catkiller395]

Very helpful and informative! Probably the best and simple guide I found so far.

[@darkkevind]

Samaunus Safa thanks! 😁

[@DJBelbe]

Ditto! Been watching tons of DIY schemstics and all have such hard to get components (all imports that would take ages to arrive). A bike selenoid you can buy anywhere! And an old car battery is found in any mechanic.

[@matthew164]

And nickle can hold more current as well

[@dagdernit572]

In need of new 18650 packs, I built one like yours last night. Just wanted to say thank you. Previously, I made a spot welder from a old 900 watt microwave that regrettably let a friend borrow. He said he let someone borrow it and that guy disappeared with it, lol. No more loans to anybody from me ever!

[@darkkevind]

Darren Reeves you're welcome dude. Not good about your other welder though 😕

[@julescircuits845]

Id rebuild that welder, microwave transformers have a built in thermal and current overload device, which takes spot welding from guaranteed nasty meltdown one day to a safe repeatable process!

[@user-zs9mu8tx9u]

Awesome video again dude! I built one myself from your previous video to build my battery for my electric skateboard, worked a treat, panicked a bit when I read the comments as some safety conscious Steve was rambling about h2 gas being produced, I did it in my lounge an I'm still here but other than that great inexpensive solution to building your own battery pack rather than buying a battery spot welder, vids are great man super informative and helpful, great invention thanks for sharing dude!

[@darkkevind]

Adam Harriman thanks man! Glad it helped and you were able to build your own, super easy right?

[@user-zs9mu8tx9u]

darkkevind was super super easy dude! Easy to get parts easy to build and easy to use, and I found your prior videos easy to follow, couldn't ask for more man! As for h2 gas when I build another pack in future am I best to use it outside or is there no reason to worry? Keep the awesome vids coming man

[@darkkevind]

Adam Harriman no gas whatsoever unless you're charging the battery. Using it, ie. discharging the battery doesn't produce anything harmful...

[@DannyTillotson]

I charged my battery right before a weld and there was a huge explosion. Thought I'd died. But thankfully it was just the hydrogen igniting in the air. Was no harm done and I'm still doing it. I just don't charge right before I start.

[@darkkevind]

Danny Tillotson that's odd, I charge nowadays after 70-100 welds and then use straight away... I've never had this! 😕

[@ICY-iC]

I get back on this video, to thanks for the idea, it's working great. I'v done it with x20 18650 batteries in parallel, and trigger the electromagnetic switch through another, smaller, 12v battery and it was doing it great. I'v successfully spot weld a large parck of 18650 with it, and everything went super well. So thanks again for the idea!

[@MihaiMihai-zw4rz]

Hello!! Please, can you put a schema ( a sketch on a paper, nothing fancy ), or make a video on how to do it with 18650 batteries ? The electromagnetic switch is this solenoid from video? Another improvement may be the addition of a fuse to prevent possible dangers. The question is, where is it fitted? Thank you very much!!

[@inso5078]

Are you still using this spot welder? If you do and the design hasn't changed since this video, I have some tips for you. - those two electrodes should be separated. Applying pressure separately gives you much more consistent welds and eliminates sparks, which appear when there is not enough surface touching the nickel stripes. - make those electrodes thicker with roundly pointed edges. I use 5 mm copper rods, point them with a grinder and make the ends nicely round with a file and sandpaper. The ends should be about 1.5-2 mm in diameter. - as for the timer controller I recommend XY-LJ02. Shortest pulse time you can set it to is 1/100 of a second (10ms). The one you showed isn't very useful, because the shortest pulse time is 1/10s (100ms) which is far too long and it burned through my cells. This way you'll have a very efficient heat transfer interface (thick electrodes) and a big contact surface (rounded pointy ends), which when used with equal pressure (sparate leads) will give you almost perfect welds. Well, they will never be perfect, because 12V is a bit too much for a spot welder, but they will be consistent at least.

[@gustavogarciaswengel8679]

A 5 amp 30 volt diode across the coil biased to the positive battery terminal avoids relay sparks and will extend the life of the relay. The timer is crucial, and easy to add to the control circuit. A pedal frees the hands and allows holding independent electrodes.

[@aswingsharif6729]

Lots of information before I start to build my own lead acid-solenoid-push on button SIMPLE YET EFFECTIVE SPOT WELDER ! Thumbs up!!

[@ryalman21]

Wow, not only great videos but you even provide links to get all the gear super fast from Amazon in the UK. Top work buddy.

[@darkkevind]

ryalman21 thanks man!

[@keithwaterhouse2845]

I just built this, it works better than my Sunkko 787a+ on 18650's, tomorrow I’ll try the 26650's double thickness. I used a rocker arm to keep the wiring tidy and mounted the switch on it which adds weight to the electrodes but otherwise identical, Great video.

[@darkkevind]

Wow! That's awesome! I'd love to see it, you must make a video or link to a photo! 👍🏻😁

[@keithwaterhouse2845]

Yup, works great on 26650's too. I just repaired my 2000w Ebike pack without a hitch so you saved me a lot of money, Thank's again.

[@darkkevind]

@@keithwaterhouse2845 that's awesome! Glad to be of assistance 👍

[@sergeantcrow]

Brilliant ! Now we can all have a Spot Welder... Thank you... Today I learned a Solenoid acts like a Relay.. Oh and a Cut Off.. That's excellent...

[@stanleytolle416]

I would make sure you have a good battery. I was working as a mobile auto mechanic and a older woman called to her house because her car would not start. I stopped by and her car was in her open garage. Now the hood was closed and I did not see any charger around. She told me she tried to start the car several times that morning but it would not do anything. Hearing this I decided to confirm the failure by trying to start the car myself. With her standing by the car and myself in the driver's seat I turned the key attempt to start. Instantly a big blam, dent in the hood, acid fumes coming out from underneath the hood and luckily the hood didn't open. Luckily she was there to see it or I think I would have some hard explaining to do. Yes I never seen anything like that before or after. I asked if she charged the battery before I came but she claimed she did not. After hosing out the engine compartment I removed the battery and replaced it everything worked fine, no overcharging or anything. All I can say is make sure you have a good battery and that if it is not sealed type, has water in all it's cells, has not been changed for several hours, you should be safe. Also have the battery tested too. Never figured out why that battery exploded or why it did not for the older lady.

[@fieldsofomagh]

Detailed, step by step video of a working project and all the wrinkles ironed out. Thanks for sharing with first class results.

[@AdrianSchwizgebel]

That is probably the sweet-spot in terms of simple yet effective for a battery spot welder! Gonna replicate this over the weekend, thanks a lot!

[@darkkevind]

Thanks!

[@DougKoper]

Great videos, I'm making one according to your information. It looks like it welds all as good as a factory $200.00 manufactured model. Thanks for the videos.

[@darkkevind]

Doug K thanks. It really does! I'd like to see your finished project 👍

[@bobhong2175]

Thank you very much! I had watched several KZbin clips on this topic, none of them provided good explanation like you did.

[@BrainSlugs83]

Neat design, this answered a lot of my questions -- FYI: Running a motor or a light bulb from a battery isn't "shorting" it -- since there is resistance between the terminals (even if it's only a dozen ohms, it's still resistance). -- It's not a "short" unless you're approaching zero ohms (which according to ohms law, would try to pull infinite amperage).

[@dylanksd]

Great video and got me welding batteries like a king! I am using bog standard cable and a tray of ice to cool the tips. Works perfectly, your massive cables are just conducting heat from the tip rather than the current.

[@darkkevind]

Dylan Scott-Dawkins that's true but with thinner cables, I found I was having to stop after 6-10 welds to let the wires cool down... With this 16mm² guage wire I can weld to my heart's content ;)

[@mattadulting]

He's not soldering so he doesn't really want to keep heat at the tips. Let the electricity create heat for the moment he's welding. The electrodes losing heat will make the rig more consistent as well

[@RinksRides]

Simple and nice setup. Lead acid batteries only make hydrogen/ oxygen gas as a bi-product of electrolysis that is a reaction to charging/over-charging the battery. Harmless enough just sitting round on a bench though. Also a very simple adjustable 555 timer IC circuit in monostable configuration using a transistor/mosfet to control your solenoid into the uS range.

[@brodpincott6181]

Hi Michael any chance of putting up a schematic of this for me to try?

[@oz93666]

Great work .... I'm working on exactly the same thing so may have some pointers ... you will be getting much more than 350A from that battery perhaps 1KA...350A is when it feeds a starter motor ... much higher resistance !! you are basically shorting it ... This high current is no problem for solenoid which is rated at 150A? for perhaps 5 secs ... you are pulsing at 50msecs so the relay contacts won't get too hot .... Here's how you make an excellent timer from scrap components you have lying around ...you need a 5 or 10 uF capacitor ... small 12V relay .... 2 or 4 Kohm resistor ... the capacitor is constantly being charged from 12V through the resistor . Press and hold the button dumps the energy from the capacitor into the small relay , only enough energy in capacitor to close contacts for 50 msecs (change time by changing capacitor) , this is the pulse, the small relay switches the big relay ... when button is released the capacitor is recharged in 1/3 rd of sec ready for the next pulse... the big relay will generate a large reverse voltage when switched off , this can damage contacts in the smaller relay(or in the push button in your current setup) ...putting a diode across the coil of the big relay stops this ...

[@karlburke276]

Nice build, I have built the same setup but I added a timer to the switch which is foot operated. I have timer set to lowest setting which is 0.1 second, this works out perfect every time. My only problem at moment is my leads are not thick enough and get hot with prolonged use.

[@darkkevind]

Nice! Just up the guage of your wire?

[@drmachinewerke1]

Do you have a link for the foot switch with timer

[@derricklewis8720]

having watched this video i built one, went to a car dismantlers for the battery, they sold me one for £20 with 550CA , rest of parts cost about £20 so in total cost me £40. have built 2 batteries so far for 2 friends they are very happy and look much better than my soldered battery, also soldering on wires for a balance board was much easier onto the pure nickle strips. Thank you is this vid that made me try

[@darkkevind]

derrick lewis I'm glad I could help bud! ;)

[@orcoastgreenman]

I don’t think a two to one mix of hydrogen and oxygen are toxic... just highly explosive. Great video and project description! Bought a solenoid the other day at my local auto parts store :-) have a few good salvaged/gifted automotive batteries in good shape in the 600-800 CCA range, old jumper cables, and a box of heavy wiring connectors I’ve built up over the years from various projects. Need to build one of these! Hopefully the high CCA batteries won’t be “too much!”

[@zakbroad9130]

ummm, you know you breath that everyday to live?

[@ahunt]

Your first video was definitely clear enough to understand the setup but definitely appreciate the update

[@darkkevind]

Thanks. Lots of people asking for more instructions and details though 🤦‍♂️

[@MrBobWareham]

Nice and simple it just will never go wrong, well it will fail one day but I love it your springy tips are easy to make with some copper braid and some tubing perhaps I will do a drawing for you so you can see how simple it would be to make then you would have a perfect connection each time as they would be spring loaded Bob-UK

[@abunatkat]

Bob Wareham I would like to see your drawing as well.

[@Devillman90]

From all the videos on youtube about Spot welder. This one just nailed it simple and easy to use. I think that's my next DIY project thank you! :)

[@darkkevind]

Thanks! You're welcome 👍🏻

[@leeackerson2579]

The ideal solution for a tab welder is to deliver an exact amount of energy every time to the nickel strip to weld batteries. You can do that manually or electronically by charging a bank of capacitors to a precise voltage level. The energy is equal to 1/2 times the capacitance times the voltage squared (.5CV^2). So, use battery to charge caps, disconnect battery, then close switch to weld.

[@laurabarnes3295]

Mine is works but dosent stick to d battery what could be the issye

[@mouhssinekandoussi1399]

@@laurabarnes3295 Maybe not enough current . Excuse can i ask you a question about the battery ??

[@JKLauderdale]

Wanted to thank you for posting this build - I'm just getting into welding my battery packs for a project I'm hoping will have some retail value. I had a spot welder from when we built tube-lights for ye olde 70's disco floors but it's pressure triggered with vertical poles. Easier to DIY from scratch than try to reconfigure a 40yr old spot welder for something that may not even sell.

[@darkkevind]

You're welcome 👍🏻

[@thumperman8490]

Great video, and just what I need to do repairs to a load of dead Dewalt drill battery packs. You forgot to mention your 18650 battery supplier as there are a lot of suppliers ...some better than others. Any recommendations? Stay safe out there.

[@marklimbrick]

It's great that you have kept everything so simple and it works. Screwfix or Toolstation do a 30A ceramic block connector. That nickel strip will glow white hot at hundreds of amps for a long time. It is the ohmic area(lots of routes probe to probe) resistance, it is not a fine wire! Spot welding is 'resistance welding' - if there was a short circuit then it wouldn't heat up. The probes provide a localised area of contact with high resistance. For the minimum safety instead of just trying to tap the button = I suggest a simple circuit of a resistor and a capacitor that charges up to 12v, then your switch button connects that to the solenoid coil. If the pulse is a bit short, press again.

[@jameskrivitsky9715]

Thanks for the upgrade info as well as the failures of burnt strips if contact time is excessive. I made a crude set-up which had partial success. Copper nails may help. Timing is the key. J K

[@darkkevind]

James Krivitsky timing certainly IS key!

[@aberavon]

What a brilliant idea, Kevin. Tried to recover drill batteries by soldering. not satisfactory. Your method will enable me to do that.

[@darkkevind]

Brian Walters thanks! That's awesome 👍

[@raymondj8768]

its a great setup u dont need a timer you have plenty of power just hit it quick n bam its done great job

[@darkkevind]

lol thanks! :)

[@dennisfox2344]

Looks like a great little spot welder, something I have needed for quite a while. Thanks for the review.

[@kylelongstaff]

great video, I happen to have a cheap foot pedal that's very tactile. I find using my big toe for the button and having two hands-free woks quite efficiently ;)

[@robinwills350]

Great video and I have made up my welding rig pretty much like yours. I've made one slight alteration in that I have used a lever moment switch which gives a much more consistent connection as you flick it and get a consistent weld.

[@darkkevind]

Thanks! Would be great to see your setup 👍🏼

[@ronsen9974]

Hi Robin, i am trying to create this setup but would appreciate if i can get some help in seeing your setup. Thanks again

[@MusicByJC]

I am going to give this a shot. Already purchased 1/2 of the items.

[@douglasbattjes3991]

Have a Solenoid, Bat, and everything but the switch,, lot better than $300. 00 mini spot welder,,,Thanks so much, Great updates on your videos,, Thought about doing it by just hooking a Bat. up to two pins, and just touching the strip, love this way much better,,,

[@Tonyplat98]

That's pretty good. Why are we paying 100$+ for arduino welders when we can just make one of these... Thanks for the informative video...

[@darkkevind]

Thanks! :D

[@Noxoreos]

@intra morph because they actually include some safety mechanisms and don't wear out over time, except on the batteries. It is also easy enough to create a custom Arduino solution including the power source for less than 50. Actually you can buy a full kit for less those 50 bucks nowadays, when you already got a viable power source. And that one is much less likely to suddenly explode, because they don't leave that much room for user error.

[@therealchayd]

I was talking to a guy who builds a lot of packs as a side business and he said pretty much the same thing. He'd spent a fortune on different types of "pro" welders and they'd all eventually failed for some reason or other, but his DIY solenoid welder was still his favourite and going strong.

[@Noxoreos]

@@PersonalStash420 you can find them on ebay or aliexpress. The keyword "spot welder" should bring up a few products. some of them sell from 25 to 50 bucks and are good enough for personal use. Just make sure to take one that's powered with a lipo battery or similar

[@ExtantFrodo2]

Very helpful and useful video that addresses any question regarding this method. BUT, "Shorting" is any Zero Resistance connection between the terminals. It is specific to zero resistance only ie no load. That said, a cars motor is not a no load device regardless that the ohms measure essentially zero. An ohm meter is not generating emf to turn it, and so does not present as a load to the meter. Clamp an ammeter on the motor leads when you power it up. That said, you're absolutely right that this is perfectly safe. I plan to build one of my own this way very soon

[@darkkevind]

Thanks! 👍

[@ExtantFrodo2]

@@darkkevind Nevertheless perhaps to err on the side of caution, a strip of that nickle (perhaps double thick) connected as a fuseable link between an electrode rod and the battery would be safest. The worry free life is better is it not? Maintain throughout. LL&P

[@npatrcevic]

You could use Tungsten rods for TIG welding instead of copper nails xD

[@pierredembele9439]

Thanks so much for the instructive video. Can it work on prismatic bigger batteries with aluminium busbars?

[@diymadness747]

You can add a 200 amp fuse, just in case if the solenoid get stuck.

[@junexjeyesmallbrain3477]

rigth

[@irate74]

Where exactly would you place the fuse?

[@Dorngrunder]

Between the positive terminal on the battery and the relay i presume?

[@errcoche]

I was thinking about that. Not nice to touch the nickel strip and find the circuit is closed. I get nervous around big batteries.

[@reefer2917]

@@irate74 anywhere on the positive battery main leads

[@Rocky3ooo]

As soon as hit the SpotWeld Button I hit the LIKE button ,great video thanks

[@markstrathern2986]

Thanks great video, everything clearly explained. One warning, not a good idea to work around batteries, especially high power ones wearing a metal ring. If you short out across the ring it can get red hot before you really notice and then you can't get it off before you loose the finger. Doesn't happen often, but a few people loose a finger that way each year.

[@darkkevind]

Mark Strathern thanks for the heads up! ;)

[@sophiechollet2643]

Very simple and effective. Well done! What you are doing is safe, but just a couple of corrections to your commentary to help others keep safe. The gases from lead acid batteries are not toxic but are explosive - so ventilate well when charging and don't do any welding for a couple of hours after charging to let the gas disperse. The battery WILL GAS WHEN DISCHARGIING HEAVILY ie. when welding! However, in a sealed AGM battery or even a low maintenance battery, this is unlikely to be a problem in this application. to be on the safe side do your welding in a well ventilated area and even use a fan to blow the gases away from the weld area. If you are using old fashioned flooded batteries then definitely think carefully about dispersing the gases (hydrogen + oxygen). A little common sense and understanding of what you are dealing with is all you need to stay safe - enjoy.

[@lawriecarr2964]

Like your Spotts, Just an idea/question re doing 4 spots in one go ie using 4 copper nails with a spacing insulator (maybe four holes evenly spaced in a bit of wood to start with) just a very little extra wiring to 4 terminal blocks? It sounds like the battery could handle it OK ???. Nothing like cutting work in half. I think your return spring idea could also work better using a bigger four-pronged foot.

[@darkkevind]

Lawrie Carr that's not a bad idea, but sometimes 4 are required and sometimes 6. Also with some awkward shaped nickel strips out would be time consuming to line up the prongs so they sat correctly. But good idea! 👍

[@wilc4u]

Very good. Questions: Can you explain or expand on why you need a Solenoid? What's the purpose of the Solenoid, why not connect the switch wire directly to the battery? What would happen if you dont have a Solenoid? And then, what kind of solenoid you used or recommend? do you have a link to the the one you used? Thank you !

[@darkkevind]

The solenoid is a switch capable of switching VERY high currents. The little switch would blow up should you try and put a few hundred Amps of current through it.

[@wilc4u]

@@darkkevind Thank you, I appreciate your quick reply! - Reason I asked is I saw this other video and was wondering why you needed the Solenoid: kzbin.info/www/bejne/n6KUi36kaLOdqac

[@gxy4833]

great video and easy to follow, spot welder working perfect with a 220 CCA battery, thank you for sharing

[@darkkevind]

gxy4 thanks! 😁

[@giftcp82]

I had collected loads of batteries but could not figure out how to get a spot weld. This is fantastic. I don't know why I am only finding this now after years of searching for a simple diy method. In regard to the switch. did you consider having a capacitor and resistor to control the timing. I think a simple circuit like that could work. Perhaps in combination with a transistor.

[@ronniepirtlejr2606]

This is a good Brute Force welder with proper amperage! None of that fancy electronic bs! Hehe

[@tomijorg]

And my fancy electronics delivers about 800 amp at 25 to 35 msec. With short protection 😂✌🏼

[@sajadeshahidpour2008]

Greetings - thanks a lot for such a detailed explanation ! I am not knowledgeable in electricity so I have one naive question if I may : why a solenoid rather than directly putting a switch on one of the cables between the battery and the welding rods ?

[@darkkevind]

One word: current. The amount of current passing through would probably melt any regular switch contactors within moments.

[@sajadeshahidpour2008]

@@darkkevind Thank you for the quickness of your response! So if I understand correctly, it would be rather hard to find a classical "button switch" for such levels of intensity, otherwise you would certainly have used one. Thanks again! PS : fun fact, in France we colloquially call those choc boxes "dominos" or "sugar cubes" :D

[@peterpham4846]

OK..I got it to work now. The battery CCA should be around 250 - 400. I change my battery from 800CCA to 310CCA. It work greats now, also the nickle strips needs to be real 99% pure nickel not plated. I had some plated strips mixed into my supposedly pure nickle batch and they did not stick at all to the 18650 battery. The real nickle strip were very easy to spot weld and held firm! Also I found an easy way to spot weld is to put a small strip of solder under the strip(for plated nickle strip only). I angled the tips and let it do the quick heat spark and it melted the solder and welded the strip to the battery really fast and hold firmly too! This process made the welding stronger and easier.

[@sparkiekosten5902]

Now that's using your noggin! I will use that idea and make good use of it! Thank you!

[@aznative_]

What issues did you have with a 800 CCA battery? I was going to build one using an 800 CCA that I have laying around.

[@peterpham4846]

@@aznative_ It's way to strong. It will burn through the nickle strips every single time on spot welding. Once I went down to 310 it work perfectly.

[@aznative_]

@@peterpham4846 that's what I was afraid you were going to say! I need to build a battery today so what I'm going to do is use a pair of my 15 foot jumper cables and hope enough energy is wasted in that set up. I'll definitely be doing some practice tests on things besides batteries before I actually try it on a battery not looking to risk the potential of thermal Runaway.

[@peterpham4846]

@@aznative_ you can try spot welding the nickle strips by angling the two prongs 45 degree or more, don't do a straight vertical spot weld..it will burn holes into the strip..or put a little ring of solder under the strip and spot weld it. This will melt the solder and make a better spot welding with the high CC.

[@alexandersingh2181]

Nice project. Thanks for sharing. Just a quick thought. You could also insert the copper nail from the top side keeping the head on. Now you can spring mount the nail using tiny spring on top of the nail head. Because there is a little room between the two screws that are holding the terminals in place. Thanks again bro. Keep them coming.

[@chrisduke3251]

"Nothing sinister" Haha, man, I'm going out this weekend to get a battery and the other parts. I'm glad I waited for this update because I was only going to get a 200A.

[@darkkevind]

Chris Duke 200A is enough to be honest, but 300A is a bit better and a bit stronger, but you have to be SO quick with that switch! Lol

[@Zain.Shikari]

Simple but better than so called expensive spot welders. Nice job 👏

[@fayebrier6820]

Doing it like this makes doing it any other way look dumb.

[@juniormorgan7458]

I agree there is no real danger of the battery exploding, but disagree that every time you use a battery you are "shorting" it. A short is where there is a direct line between the anode and cathode with no load in between. A light bulb filament is a load because it offers resistance, which is why it lights up.

[@shinobi6622]

Well, now I'm regretting not grabbing that solenoid from the junk yard last night..

[@anothersummer2782]

What kind of solenoid can u use? I'm only aware of starter solenoid or is there anything smaller.

[@mkorn3492]

The best guide ever uploaded on diy spot welder dude! Your amazing!definitely gonna order the pieces and build one!

[@darkkevind]

Μάριος Μιχάλης thanks! 😁

[@84ggo84]

excellent craftsmanship, nice low-cost project. I appreciated the copper nails really a great idea ....... ty

[@padysrini9955]

Awesome video. For a beginner, this was very helpful. Thanks.

[@darkkevind]

You're very welcome 👍🏻

[@artfulcoyote]

Nice update thanks..

[@darkkevind]

artfulcoyote thanks! ;)

[@YakubKristianto]

20:40 screw it up, and you're done XD

[@scottl7644]

Received some copper probes but these are blunt. How should I sharpen them and would 8 or 10 awg cable to better to reduce resistance??? The cable that came with the 12v max kits says there are 12 and 10 awg but from China they don’t look like the legit 10 awg or 8 I’ve got??? Sunbed.

[@darkkevind]

Sharpen them with a file or sandpaper. I wouldn't go lower than 10awg to be honest.

[@nelsoncuesta6057]

I'll have a go making one, if I get stuck would drop you a line

[@FIGUEIRINHA]

nice and inexpensive idea! still working fine? I guess the grey cable can be shorter - less loss in it nickel strips are really expensive here. 6mm copper wire are not. there is some problem to use 6mm (semi)rigid copper wire? it can handle 36A and I can hammer it to be more flat in the weld place

[@darkkevind]

Still working absolutely fine 👍🏼

[@FIGUEIRINHA]

@@darkkevind and about the copper cable? you tested / tried do weld it using this "machine" ?

[@darkkevind]

@@FIGUEIRINHA I've done thousands of welds with this welder. Not sure about the cable, I'm using 16mm2.

[@FIGUEIRINHA]

​@@darkkevind grateful for the return. looks really nice! I will ride one for myself. but I am talking about using 6mm wire in the cells replacing of the flat nickel plate.

[@chrisduke3251]

12V 35Ah 330A must be a UK thing. In USA, the search engine always converts A to Ah, and all the parts stores know how to do is add what car it's for into their system. None of the batteries on display show A ratings. Anybody here in the states who can help? Some truck batteries list cold cranking amps, but they usually start around 800.

[@darkkevind]

Chris Duke yes, it's CCA that you want to search by... CCA is the same as A basically. It's the amount of current the battery is able to discharge to the starter motor...

[@chrisduke3251]

Thanks. Yeah, it looks like no car batteries in USA under 500A (CCA). I'll have to look at motorcycle batteries. A motorcycle battery may be a better choice for me anyway because it's more portable on my E-Bike. Now to dig up an old laptop so I can break the dead batteries out of it for practice.

[@darkkevind]

Chris Duke you could try it... Mine was crazy at first @ 330A but it seems to have settled down now, even though I've kept the charge topped up...

[@NeoAH90]

Use the more big battery for a motorcycle 12-14A 12V battery

[@njfulwider5]

Hope you found your battery? But at AutoZone, I have purchased the (Lawn & Garden) Batteries for my welder. They have a fairly cheap 250CCA or 325CCA batteries" under $40". I have experimented with both, and the 250CCA giving me the best welds.

[@carlomariamosco]

Only brilliant people can develop such simple solutions. Thanks for sharing it

[@AC-nt1ph]

How about a wireing diagram. Thanks.

[@darkkevind]

kzbin.info/www/bejne/pJ65ooihg8-omM0

[@rr8y]

Great video and looks solid. can i use a relay vs a solenoid?

[@jons6125]

If you need solenoids explaining not sure you should be making battery packs quite yet sorry 😐

[@darkkevind]

Agreed.

[@rovcanada1]

BTW, your 1st video was top-notch for anyone that has a basic understanding of electrics. To be honest, anyone who starts banging on about exploding batteries etc., really shouldn't be attempting anything but adjusting their Warrior® armchair height, ffs! Anyway, I've not made a spot welder yet, but I was pondering whether using spark plug electrodes would be the way to go? Most have suitably sized platinum-coated tips, and are designed to last for bucket-loads of sparks. Smash the ceramic insulator off, and Robert is you father's brother! Also, I'm wondering if a 3-way automotive toggle switch set to [OC~SC~OC] would be a good way of getting the solenoid energising time perfectly tuned? As you throw/push the lever from open circuit through closed circuit, and on to the opposite open circuit. The short time that the lever closes the contacts as it passes over might be perfect?

[@Fungineers]

So when u press the button doesnt all the 300+amps get dumped into the control wiring? So the button and the small wiring all run300 amps while they are not supposed to. Amirite?

[@darkkevind]

No, the button activates the solenoid, which then in turn has all the current running through it... Not the little switch.

[@Fungineers]

@@darkkevind thanks for the quick reply. yeah I understand, but the button is also wired directly to the battery and when you push it, it basically also draws it's current from the battery. So whats keeping it from drawing big amps?

[@darkkevind]

@@Fungineers things you connect to a battery only draw the necessary current for them to work... Just because the other circuit is on the same 'ring' doesn't mean that the current going to weld the batteries is also going to the switch.

[@Bravo-ry9st]

Simple & perfect ! Best DIY I have seen for a battery spot welder. Thank you !!!

[@darkkevind]

Hey, thank you! 😁

[@faizanmuneeb6801]

Improvement Idea. I might be wrong. Add a little 12v relay. And a capacitor 4700uF or just try different values whatever works better. If you know current draw of solenoid you could prolly calculate the exact value you need. When switch is pressed it turns on relay. Relay connects positive (or negative) through capacitor to solenoid. It comes on and goes off when capacitor is charged. And use NC point of relay to short the capacitor to discharge it when switch is depressed. Hope i was able to explain my idea

[@faizanmuneeb6801]

Might cause arcing inside the solenoid though because the voltage would be dropping off instead of cutting off. Could add multiple values of capacitors with a selector switch to set trigger time

[@pierrickmiston3702]

Just built one...Works great.... Thank you for the detailed walk through

[@darkkevind]

Awesome! You're welcome 👍

[@vedatvural9768]

After two months of search on youtube I come cross with your videos. I found your videos very useful, Clear, simple. You describe functional and cheap to built device. What else we should be looking for more... THANK YOU for your knowlewdge and experiments that you shared with us darkkevind. I already ordered my components to built my own spot welder very soon.

[@darkkevind]

Vedat Vural you're very welcome 👍

[@lowjer]

Love it! Only thing I'd probably add would be an arduino timer that you could program the length of the relay engage cycle...and maybe a secondary relay wired up as an emergency shutoff if the first relay stays on too long. (if the arduino is fast enough that is).

[@naknakacknak]

Good thought, but I think you would need a bank of MOSFET devices. They are solid-state and would respond to very short times. I think a relay or solenoid has physical limitations and would not respond to short times properly.

[@sunilsenevirathne4245]

Very nice explanation any body can understand thanks for your explanation l wishyou post mor videos about your ideas l appreciate so much

[@luke040655]

Great video can you tell me what size yellow wire do i need that goes to the switch

[@darkkevind]

Anything will do really... something like speaker wire will do 👍

[@luke040655]

@@darkkevind Thank you will give it a go

[@harshwardhanpradhan5320]

Superb. I tried building one and it worked like a charm. Thanks a lot... 👍🏻

[@andriusst]

This is awesome! Love the simplicity. Just to add, I think a car starter pulls more amps when cranking the motor than this welding thing.