Make your own Crude Battery Spot Welder with a Car Battery!

[@arnab1804]

GreatScott = Potentiometer ElectroBOOM = Full bridge rectifier!!!

[@deadbird99]

Finally a spot welder I might build! Thanks a lot!

[@denndy]

Your comment is 2 Days old. This Video is uploaded 2 Hours ago. KZbin?... What is going on?

[@deadbird99]

@@denndy Patreon.

[@GRBtutorials]

I might build the other, though, because the reason it didn't work was some critical mistakes when designing the PCB, not its feasibility, and I don't have a spare car battery nor a 1000 A relay (which are quite expensive).

[@TecSanento]

you may even use a 200A Battery disconect Relay - as i did - wich is cheaper

[@raiptv3393]

Old saw blade kzbin.info/www/bejne/jaWxnJKnfsiBbbM

[@michikipsy1951]

pro tip: don't crimp or skrew soldered wire; it will get loose after a while - after all, nicely done project! like

[@mickgibson370]

I used a homemade spot welder 40 years ago. 120 vac to 15 vac using a 12 v octal timer and 1/4 kwatt transformer. Did flat heater wires! The most expenses part was the 1/4 kwatt transformer!

[@loukashareangas4420]

I would be very interested in how that big relay is constructed, specifically the contacts. Would you do a teardown? It seems to be screwed together so the teardown shouldn't be destructive.

[@jkbrown5496]

Generally, they are just solenoids with a thick copper washer on the end of the plunger that is pulled into contact with the two high amp terminals when the coil is energized.

[@loukashareangas4420]

Well, yeah, I know how a relay works, I am more interested in the contacts themselves. Can they make the contact (easier) as well as break the contact under a 1000A DC load (doubtful), or is the contactor supposed to be operated under no load only. Those kinds of details.

[@loukashareangas4420]

@@mustafayasiraydin exactly!

[@Schniels65]

Ich würde auf Graphit Tippen.

[@jkbrown5496]

@@mustafayasiraydin Perhaps and I know they use alloys for high voltage contacts. But the ones I've seen generally use the large contact surface area, along with dual contacts one on each side of the disk to deal with the low voltage, 12 volt, high amp car solenoid switches. The solenoid action and the spring return ensure short make/break periods. These are expensive commercial devices with exotic alloys.

[@TomaszWiszkowski]

Don't mean to spoil the fun of building spot welders to anyone, as this is a pretty awesome thing to do, but in case anyone needs something to get the welding task done, welders have now become cheaply available on Amazon for about $50, or AliExpress for about $30-$40. Probably not as great efficiency as ones we can build ourselves, and certainly less configurable, but get the job done. Sharing this only because i recently needed just that to recover a 84V battery (leaking cell). My first impression after coming across this video was that the welder would cost as much as a power cell, but thankfully it wasn't that bad. Bought myself a tiny and great looking box that gets the job done.

[@chewbaccarampage]

I've started watching your videos because I wanted to learn some basic electrical engineering. Three years later and I actual understand what's going on! Thanks for sharing your ideas and lessons.

[@hidde3064]

You are the hero I needed. I messed up some cells in my Esk8 battery pack because of broken parallel cconnections due to solder connections failing. I don't want to resolder new cells so I need an affordable spot welder and this is definitely a viable build. Thanks for persisting and finally designing a working spot welder. I cannot thank you enough.

[@AlCapwndYou]

For those newer to electronics, like myself who were wanting to build something like this, there were a few components that were not included in the list of this video or in the Instructable: The red film capacitor appears to be a Würth Elektronik WCAP-FTBP Film Capacitor (which is what came up when I was finally able to get a clear shot of it at 6:10). I am not sure if this is the 470UF cap or the 220UF cap. WE does not carry a 470uf capacitor, but they do carry ones listed as 470nf (.47uf). So now I am wondering if I am looking at the schematic incorrectly, if it is mislabeled, or if the standard aluminum cap is 470uf and the film cap is 220uf. This is why it is important to label all of the components during assembly, because there is no way of telling what is what for those who are new. I tried to find the 10U capacitor, but couldn't see one on the project. Instead, there also appears to be a tiny SMD Ceramic capacitor that is soldered on the bottom of the breadboard. This was shown as a loose component next to the WCAP-FTBP at 3:41, and then shown on the underside of the board at 4:41. I am presuming this is the 10uf (not nf?), but at this point I don't know. I would appreciate some clarification from GreatScott or more electronic-savvy individuals on this channel to be able to correct me if I am wrong on these observations, or the labels of these components, but I thought I would try to help those who are confused by the omission labelling of some of these components in the video. An updated PCB trace would be amazing to help those looking to repair their 18650 battery packs without needing an electrical engineering degree in order to complete the project. As a backup to this project, since I am not confident in being able to find/layout the exact components, I plan on toying with using a 555 Timer in monostable mode with a potentiometer to control the pulse duration of the relay. EDIT: After re-examining the schematic, it would appear that the 470uf cap is the standard aluminum capacitor as it is next to the 12V, and since the red WE film cap is next to the TC4420, that would likely be a the 220nf (.22uf) - but I am not certain.

[@vivi-fe5rj]

Thanks for the write-up. Apart from playing around with assembly projects, I'm an absolute beginner at this kind of thing, but I came to the same conclusion that the red film capacitor is 220nf, and that the 470uf is a standard electrolyric capacitor. Hopefully that's correct, because waiting another 2 months for Aliexpress will kill me haha. I wish he made the parts list a little clearer, but the schematic certainly helped. Like you said, I'm just some guy with limited electrical experience trying to make a cheap spot welder but for what it's worth, I think what you're saying is correct.

[@conorstewart2214]

If you go to the instructables page it has the schematic. Capacitors are mostly generic and interchangable. As long as you use the right values and voltage ratings then you should be fine. If you can't build this from the schematic then you likely shouldn't be thinking about building something like this and should instead just buy a spot welder.

[@AlCapwndYou]

@conorstewart2214 What a helpful and insightful reply to a genuinely curious inquiry 3 years ago, which may or may not be relevant today! I am so glad you took the time to read what I posted and decided to have a trite smug gatekeeping response instead of taking the time to actually educate others, like the purpose of this channel is for. I am also grateful that you said, "as long as they are the same value, it doesn't matter" because heaven forbid RIFA capacitors were a thing. There is a reason why Replace Immediately Fire Ahead is the joke acronym. So yeah, no, you're wrong. Components matter. But hey, if you are not able to have a basic sense of time, you probably have no business replying to infer that someone wanting to verify a tutorial lines up with the schematic and proper component selection is too stupid and should just, "buy the thing". When, in fact, at the time of this posting, there were serious deltas between them. It's not like a schematic has EVER been wrong or anything... Have a great day.

[@lukas7626]

I build the exact same spot-welder. But I upgraded it then with mosfets instead of the relay. I also replaced the car battery with a "car starter Powerbank". It works perfectly.

[@reallyiffy]

Cable shoes 🤣 that must be the German Translation for ring terminal! Love the German language.

[@jaras1969]

Well here in Denmark we call those "Ringkabelsko" (Ring cable shoes), as opposed to Spade connectors (spadekabelsko) or Pin terminals (stiftkabelsko).

[@supercunthunt7756]

Yes, your right🤣 🤣

[@andreidicu2882]

In Romania we call them "papuci" and it means shoe so nothing out of the ordinary here.

[@reallyiffy]

@@jaras1969That's really interesting! Does that mean that "shoes"(sko, and Schuh for that matter) has a meaning that is more broad than shoe in English? Possibly something like distal appendage cover?

[@FlyingShotsman]

@@reallyiffy The word shoe is used for electrical contacts in English also. The sliding contact on an electrically powered trolley, for example, is called a shoe.

[@emersonsrandomvideos248]

Hey great scott you really are "THE ELECTRONICS GOD" I hope i can make my own spot welder base on your circuit diagram. Excellent job!!!

[@cfzone8685]

When I am thinking about building a spot welder, here you are making a video! Great video!

[@Jajaho2]

Hi Scott, I really enjoyed this video. It was very well made as usual, with nice drawings explaining everything. But the project(s) itself were the main star, very creative and what I liked especially was that you finished the job and didn't just call it a day after the first failed attempt, goes to show that stuff like this needs several iterations, which is very important IMO.

[@awesomefacepalm]

6:57 isn't it a bad idea to tin wires that you put in screw terminals?

[@Nedeles]

No, you have a better and stronger connection thats is also protected from corrosion

[@nrdesign1991]

It is not recommended, since the solder will settle after a while, leading to a loose screw connection. It is better to crimp the wire with a ferrule to cold-weld the strands together, and also provide a grip for the screw holding it in place. Tinning the wires is forbidden in the electrical wiring of houses, and in manufacturing of switching cabinets.

[@awesomefacepalm]

@@nrdesign1991 that's what I was thinking. I have a 3D printer and I remember the biggest nono was to solder the leads for the bed. Apparently it was a reason for loose contact and melted terminals.

[@mat.phillips]

Yes it is, definitely do not solder wires to use them in screw terminals.

[@Djhg2000]

@@Nedeles It actually gets a weaker connection because the solder has a creeping effect over time. It's a common mistake for newcomers because you intuitively think the solder makes it into one large conductor, but then you don't account for the odd microscopic properties of solder.

[@michak8029]

for screw connection of the cable you shouldn't solder the cable... IPC-A-610 norm...

[@yereverluvinuncleber]

The high surface area in the copper in the cables exposes to oxygen which eventually tarnishes and causes increased resistance, generating heat in the cable and reducing the current. Soldering it as one mass reduces that corrosion and keeps the current flowing. If it was higher voltage (240v) and continuous current flow then I would have said not to solder but for 12v it is fine as long as that screw connection is good and the solder is soft.

[@mich29sm]

Yes, it is recommended to use ferrules instead. The solder become brittle under mechanical stress (and with time) and the termination becomes very unreliable, causing high resistance/hot spots.

[@yereverluvinuncleber]

Agreed, always difficult to decide what to do. For an application like this, with only occasional usage it should be fine.

[@NL00iemand00NL]

I did a test on this and after about half a year the wire was lose and didn't make contact anymore. With these connectors it could work since the screw itself pushes the wire together if you screw it tight enough altho I wouldn't recommend it.

[@TheAshish60]

Ive made a spot welder by using microven transformer. And I control the 220v input of the transformer with my diy SSR with a triac which can easily pass 20A. And rewinded the transformer so the output is around 6-7 volts and its the cheapest spot welder with 2 pulse system

[@petersage5157]

Nice project! I'd simplify it even further by replacing the Arduino with a 555 timer. Same footswitch and RC tank, but simpler trigger circuit with no need to code.

[@Inventor101]

Fantastic job great video like always 👍

[@GapRecordingsNamibia]

Hi GreatScott! Thank you for your great content! I found in your code that when the "timems" reads "0ms" the welding tips can still be live/ shorted if the foot switch is pushed by accident. The code in your void weld reads as follows: void weld() { if(digitalRead(2) == LOW) { digitalWrite(9, HIGH); TCNT1 = 0; OCR1A = timems * 250; wait = 1; detachInterrupt(0); } } I have amended the following lines to make it safe. void weld() { if(analogRead(A0) == 0) digitalWrite (9, LOW); else if(digitalRead(2) == LOW) { digitalWrite(9, HIGH); TCNT1 = 0; OCR1A = timems * 250; wait = 1; detachInterrupt(0); } } Regards Charles

[@Moonwalker917]

Thanks a lot for this tutorial. I have tons of 18650s and I'm building a huge 25s1p pack to power a 1940s portable tube radio which requires a 90v battery and I was going to solder them the "bad" way, with a soldering iron... Anyway, some of the stuff like the relay can be found for much cheaper on ebay: Arduino Pro Mini 1.48€ TC4420 1€ IRLZ34N 1.40€ (price for 1 in packs of 2) DK238 Relay 19.68€ Foot pedal 1.15€ 0.96 Oled display 1.99€ Battery terminals 1.63€ 200A fuse holder 5.40€ 200A fuse 0.40€ (price for 1 in packs of 5) Copper nails 5.10€ (price for 5) Which makes it a total of around 40€ not accounting for thick wires, potentiometers, veroboard all that stuff. But let's suppose it's around 15€ (10€ of cables and 5€ of extra hardware) so the real total price is 55€. You could even remove the copper nails from the list and replace them with heavy duty ground wires if you can get your hands on a foot or two. If you want to go the cheaper route with a 555 monostable circuit you can shave 10€ off the price. And if you think the big chinese electronics lobby is trying to scam you with their scary "safety" gibberish simply get the relay and a foot pedal just like AvE did: Spot welder for 30€!! (anyone reading this, please don't do that, accidentally burning down your table or you house is not worth it for this price.) And again, thank you for this video! Love these useful and effective projects!

[@ipissed]

I used an arduino with a potentiometer and simple timer code to pulse a 5v 30a relay to pulse a Ford starter relay. Cheap and simple. $20 if you already have an arduino.

[@gerrymcerlean8432]

Great video. A starter-motor relay (from a car) can be bought very cheaply (mine was free) from a car dismantler.

[@twistedshadowsaf]

Listening to this while my eyes are closed made me super aware of your breath in before starting each sentence.. 😅

[@cameron20020]

I'd love to see that relays contacts monitored with a scope. Curious what it's minimum on time is or if it has any contact bounce. Glad you got the project working well!

[@RinksRides]

Thank you Great Scott. Your last designs inspired me to DIY my own spot welder first from a car audio 20V 1F capacitor. It was not powerful enough even charged to 18V. So I turned to a car starter solenoid/car battery/timer configuration back in February. Simple, consistent welds on my 13S8P bike pack from recycled laptop batteries, (don't use recycled laptop batteries for an e-bike). 880CCA car battery: have, $16 starter solenoid from autoparts store, 3D printed holder for spring loaded welding tips recycled from an actual automotive spot welder and processed in a lathe. Borrowed the auto-pulse idea from Maletric's design. No idea how many joules i'm welding with, enough would be my guess. 15mS seems a happy medium between 8mS just starting to contact and 45mS blowing holes through 3 layers of nickel strip.

[@8867348]

This would be handy for so many projects. Not just electronics. Great build!

[@richardnanis]

Interesting idea but a few remarks on that solution: 1. Why do you use an arduino setup? Its so much easier just with a classical NE555-timer with the same precision :-) 2. I tried big solenoid switches too with a 66 Ah car battery. They wont last long as the current can easily raise over 1000 Amps for a few ms. Even below 1000 Amps the switches wear out rather quickly and tend to stick! The fuse will be your only safety measure then. 3. In my opinion an electronic switch without mechanical contacts is much better here (power mosfets). 4. A good crimp is much better for power connections than soldering. And soldering strips to put into screw terminals is generally a bad idea - as already mentioned below. But i fell into the same trap a lot of times but i had cases where these connections went very bad after a time due to mechanical stress and settling of the solder.

[@messermachen]

I liked the idea of GreatScott and I build the same circuit with the same solenoid and had a similar problem with a 54 Ah (about 500 A CCA) car battery. After welding about 150 cells of 18650 the welding properties were getting more and more worse. In the beginning i could weld with 30 ms. At the moment i had to increase the timer up to 65 ms to have a connection which is also not as good as when doing the first welds with 30 ms. I also think that the solenoid does not like the use for many welds. Therefore i will try to use the circuit for driving some MOSFETs instead of the solenoid.

[@itsmilan4069]

Finally a proper working diy spot welder we'll need a "DIY OR BUY" video to for this one

[@cxmmax4265]

finally a spot welder wich work and is not dangerous to use on this Channel, look great, i'm just a bit disappointed that it's not a cd one, anyway this one work and is cheap so....

[@greatscottlab]

Glad you like it :-)

[@cxmmax4265]

@@greatscottlab sure

[@johnfarris6152]

Knowledge is better than love and it's only getting better everyday.

[@danibiomedicalengineer860]

Legends straightaway proceed to end, and then rewind whole video and watch 😊

[@dagdernit572]

I bought a similar 18650 battery spot welder made by Malectrics. It is very nice to and was about half the price. Before getting it, I tryed making different welders myself. The last was using an friends old microwave oven transformer. Wife was nervous every time she saw me using it and made me get a good one. Night and day difference on the quality of the welds. Unless you really know what you are doing, stick with buying one.....

[@ahmedsiddiqui9515]

Amazing !!! You have access to really high class accessories, tools, components and all that is needed for any projects.

[@mid9ightwalker]

There is another very popular and relatively easy way, It's to use a rewinded transformer from the microwave oven as a power source for spot welder. It would be nice you to make the video about that.

[@danielspastars5298]

You finaly nailed it. Now make functional welder

[@ralfblumhoff7930]

The flyback diode extends the set welding time, because the relay shuts off only when the magnetic field in the coil is reduced

[@BillySugger1965]

Ralf Blumhoff V = L x dI/dt. If relay current is 100mA and inductance is 1mH and mean voltage across relay during decay is 6V, then inductive hold time is around 16us. Negligible for a device operating in tens of milliseconds.

[@ninadtaralekar]

Hey Scott, that's a great video to introduce spot welding and also explain in detail the whole schematic of welder circuit... Nice built up... Thanks

[@paco_rider]

Another video = another reason to be subscribed 👍👍👍

[@keithking1985]

Your projects always look so clean with everything brand new. NICE😊

[@traced82]

Never tin wires clamped in screw terminals!

[@The231447LucidDevTeam]

how come? Just wondering

[@zaprodk]

@@The231447LucidDevTeam The solder cold flows under pressure. It will lead to a bad contact, heat and fire in the end. It's a big NO-NO.

[@The231447LucidDevTeam]

@@zaprodk makes sense. thanks for explaining

[@traced82]

@@The231447LucidDevTeam solder gets kind of weak over time and connectors heat up because of higher resistance. you have to crimp those connectors.

[@djruido1]

I’m so glad you reviewing this spot welder, and make a different one from it

[@johannes5219]

Awesome that you were finally able to create a working DIY spot welder!

[@greatscottlab]

thanks :-)

[@MrPronoz]

For cheaper option just use car starter solenoid :)

[@Hamid9e]

Cheap option if you want to make holes on the battery...

[@Hamid9e]

Just get a microwave transformer and a cheap controller from aliexpress.

[@Ulrich_5000]

Nice informative video, thanks. But the solder skills are improvable.

[@snaj9989]

yesterday I looked for a DIY video for spot welder then I watch the old video. I was thinking when he is going to try again :D

[@unknownsauce3768]

Wow! Swap out the expensive relay for the solenoid off a car starter motor (which includes a relay in it) and this is almost free!

[@moritzkoslowski5920]

I am not an electronics super Student like you, but I managed to build such a simple Version 2 Years ago. The point is that often the simple Version is the best version. My Spotwelder only consists of a Car Battery, an Arduino, a Resistor, thick copper Rods and Powerful Mosfets, I control the on/off time via my Laptop, so no other complicated circuitry. This stuff is literally no Rocket Physics. I did not even made the Math for on/off Time of the Mosfets. I just tried around a little bit until I became good Results. I think it is a little bit amusing that you tried these complicated versions when the key is simplicity. But nevertheless the approach with the Supercapacitors was pretty interesting. Greetings from Hamburg.

[@kubaxd25]

You should not tin wires while using screw connectors. The solder can corode and the connection will come loose. The best way is to use special crimped connectors made of copper tube.

[@bakuhost]

Microwave transformer and big relay on the primary side driven by 5V arduino relay is good option I use it and it's great and muuuuch cheaper

[@bakuhost]

@@closure4791 Yes. Relay is in the 230V side so it can be smaller and much cheaper. It is also faster because those big ass relays capable of hundreds of amps have to move large contacts and it takes time. Only down side of this relay is that it is using 230V to switch. But 5V arduino relay module is well enough for switching relay that powers the transformer.

[@RealitaetsverlustTV]

@@closure4791 There are modules available on Ali-Express which do exactly that. They offer precise timing control and zero-crossing-detection. Some of these modules even offer double-pulse welding and they come with a powerfull SSR allready soldered in.

[@davey2k12]

Least someone got good idea lol

[@DrexProjects]

I just use 2 copper wires from a car battery. I press 1 down on the Nickel Strip Tape and then touch the other one on it. Works for me. Minimal parts.

[@shiftyjesusfish]

I gave just come from the other video and this is a much better idea! Too bad I'm a year late to this party.

[@DMadHacks]

Connecting batteries with batteries... Batteryception.

[@nilswegner2881]

It's always nice to find people I know from other comment sections under videos from another KZbinr... Gives me the feeling that there's people out there that think the same way I do Sadly it's Sunday today so your catch phrase doesn't work

[@davidrubio8673]

how did you get over here, i always see you on Wintergatan Wednesday

[@nilswegner2881]

@@davidrubio8673 that's why I was talking about his catch phrase...

[@azyfloof]

You're a long way from home :P Hope you're well :D

[@DMadHacks]

It's great to know there are Wintergatan fans all across the internet. Have a great Sunday my dudes.

[@blackwingmaster141]

Don't forget to consider fact that relays require some time to swich on/off

[@kaoploAlt]

I don't understand how any of this works but I still enjoy these videos.

[@JS-kv8ey]

Congratulations! You did it! :)

[@greatscottlab]

Thanks :-)

[@electronic7979]

Excellent project 👍

[@crripper9770]

A Bulletproof plate for only $2 dollars, now that's what I call a good promotion :]

[@warrengray610]

Hi, that project is super, and now something you can rely on! Happy days!

[@frankmeyer9984]

At the moment I'm converting a 230/24V 16.67A transformer to a 2.5V 150A transformer. Let's hope that the current is big enough to weld some 18650... 🤪

[@tonythediyer8537]

Missed you last week. Good build, nice demonstration.

[@jessearrazola4283]

Por fin un experto en lo que hace, gracias por compartir tus conocimientos

[@chriss9836]

I've seen and used an even more primitive version. Take all the timing and foot pedal off, build a holder for both electrodes so you can use one hand to hold them, and connect a momentary button switch to the relay. Of course his will be far more consistent than the one i used. Also a far cheaper high amp relay is a starter solenoid and can be found in any junk yard for $10 or less.

[@pieceofpotato7883]

Some guy on the youtube just built one with must a mot, 2 relays, few leds, buttons and a few capacitor, the first relay is connected to a button and a 16v cap, he basically discharged the cap to turn on the relay for few seconds to turn on the second relay that will connect the mot with the wleder electrod. He also built it so the cap is easly swapable to change the pulse time

[@long-timelistenerfirst-t-us2yy]

seriously, this was one of your coolest videos to date 😎

[@noobulon4334]

You can actually get some really beefy mosfets for not that expensive for lower voltage applications, $40 for a 330a rated mosfet! (Max 40v)

[@trentjackson4816]

You are an awesome engineer. You could get a job anywhere doing anything! There must be more good money making KZbin videos?

[@mateuszsobierajski1097]

0:49 "diy crude oil refining" Great Scott the oil tycoon CONFIRMED! :D

[@Unmannedair]

thanks for this idea, i actually have most of this already. saves me a bunch of money to get started.

[@vasiavra]

Hello, For those of you who consider the price of the relay too high, you can do the same job with a much cheaper starter solenoid from a motorcycle. Those come really cheap in my country, about 5 euros. And you don't really need an OLED, since they are a bit expensive. You can do just fine with a 7segment. Be sure to not purchase just the bare bones one, or if you do, purchase a bcd to 7 segment decoder, and a sipo shift register (if you want to save pins on the arduino). Also, you don't need the arduino, if it is expensive where you live and you don't wish to wait 2-3 months for aliexpress/banggood (that's the waiting time for me in my country). You can do just fine with an atmega328p programmed in a arduino board or via ISP. GreatScott! has explained how to do so with an attiny85, and the process is similar , same pins, you just have to locate them. Kind regards. Awesome video, by the way. Congratulations !! :)

[@TommyCullen-VacuumConnisour]

hallo,du bist die beste made by someon in the uk

[@VKRenato]

Fantastic project, keep doing I really enjoy watching your videos. Thank you!

[@qwaqwa1960]

You shouldn't crimp/screw tinned wire. The soft solder will compress, and lessen the contact pressure.

[@Gabriel2.0]

I was actually thinking to buy one from eBay but after your video, I might give this one a try.

[@JamesPotts]

I never thought of using a starter solenoid. Very cool idea.

[@MrBlackFiction]

Hey Scott, Nice Move. I wanted to build it like forever. Thank you for your video and the code...

[@jsaturnus]

how about the accuracy of the relay? Because of the mechanics there will be time needed to turn the relay on, and the energy in the coil will flow thru the diode and keep the relay longer on.

[@ankitjha8413]

congratulations for 1M subscribers 🎉🎉

[@GigAHerZ64]

8:03 - you are using caliper wrong! You should always put the material you are measuring between the tips, not in the middle!

[@xoblyxanier]

Exceptional build, good job!

[@technicallearneronlysaarth2097]

That idea is very helpful us to done our project related with spotwelding Thanks to you for this video

[@IrishSkruffles]

So.. whats the hysteresis time of that big relay/contactor? There should be a minimum on time specified in the datasheet somewhere

[@filipvranesevic8722]

@@Mr.Leeroy bouncing can actually be a good thing here since it simulates dual pulse spot welding :)

[@budandbean1]

This is so great, I’m already getting the components to build my own... Thank you so much!

[@Calthecool]

Instead of using the arduino to control the pulse time, could you use a 555 timer in Monostable mode?

[@rolandmeiner4970]

Finally an other video

[@klave8511]

Arduino plus display or 555 and some writing on the pot panel? That is the question.

[@helmutheller1538]

I was immediately thinking the same! :-)

[@TheChemicalWorkshop]

Finaly ! After the hate on last video i'm glad you did it (more or less)

[@V8Power5300]

The easiest and cheapest way is still using 3 alligator clips, two pieces of copper wire( as the electrode) and two pieces of metal. Just hot glue the two electrodes together at the right distance. Hook one side directly to the battery. Hoot the other side to a metal object like a screwdriver. The other battery side goes to some other piece of metal that is secured. Hold the electrode on whatever you want to weld. Then strike the screwdriver on the metal. Depending on your speed the power is controlled. Use thin alligator leads as they act as a fuse in the worst case. has worked nicely for me

[@841106noel]

I've got one great spot welder on arduino and microwave transformer. But not long ago I buy 350F 2,7V supercap (8$). I just welded to supercap terminals wires and copper electrodes, and thats all. Simple and efective spot welder :) Just I need to be fast :P

[@shhh7698]

I love ur videos great scout!!

[@LePhone620]

Why did you used the big relay instead of the mosfet? Isn’t the relay lower and less precise in term of time? Thanks

[@mikeymike437]

Lol, I simply discharge a 25v, 20000uF capacitor - the pins can serve as the electrodes. Works like a charm every single time - Ive prob welded a few dozend li-ion packs that way...

[@aronrad]

Pretty cool! Noob here, how long do you have to charge the capacitor to be "fireable" again, i assume a few seconds? Also what do you charge it with, a car battery?

[@mikeymike437]

@@aronrad You need some sort of power supply, anything that will give you a stable, preferably 25v. Id say 18v is the minimum for it to work. Some old laptop power supplies run at that voltage or maybe you have an 18v li-ion power-tools pack that you can use to charge the cap. Also two 9v block cells in series could do the trick. Its harder to get a hand on 20000uf capacitors tho... My tip hence, buy two inexpensive 10000uf ones and put them in parallel. Good luck! Oh and as for charging time - just go with 30s and you'll be fine in any case. And make sure u got the polarity right otherwise they will blow up on you...

[@chrisbrett1857]

@Mikey Mike - I'm really surprised you get such a good result with such a small capacitor. Have I read it right - 20,000 micro-Farads? Theory says that size capacitor at 25V can only store/deliver about 6 joules of energy (0.5 * Q * V ^2 = 0.5 * 0.02 * 25 * 25 = 6.25 joules), which seems WAY too little to make a weld. My researches suggest that 40/50 Joules is the minimum, and that's with a really well-controlled and timed delivery pulse (preferably a double pulse). I've got to get me one of those capacitors. If it works, you would seem to have discovered the secret of cold fusion, Sir :-) ! Are you quite sure about the capacitance?

[@zaidmughal9772]

Stay Creative and I will see you next time Love that line

[@ChristianJoyAzucenas]

A successful project Scott, Congrats

[@chanakasat1]

Finally you have done it! 👍

[@256k_]

thank you for convincing me not to try this project :D I love electronics, but when it comes to high power/amp circuits, i don't mess with that

[@RichardBronosky]

4:10 Why do you need a mosfet driver in addition to the mosfet? (Why not just use a logic level mosfet?)

[@anthonyvolkman2338]

Very well done! I do car audio and like those battery adapters you bought.

[@mickgatz214]

Great Video!, GreatScott! :) I'm looking into creating battery packs, slowwwly ... Merry Christmas!

[@TusharGaurav]

I want to weld my car with this car battery welder!😂

[@csedwik]

not good because the whole gnd is the same