Thank you Adam. $20 well spent! It's worth at least twice that in entertainment value! Mine you the video title is a little misleading. It should read "Super Cheap Smoke Machine... single use only"
Its more like somthing went wrong my spotwelder from just 7 euro from Alie express is Just a super welder and really works verry good i must say my buids is a lifepo 4 56 ah 13.33 volt 800 watt accu by the way
Absolutely no. Those welders are awesome. The main fault is of the operator. Because if you use a weak battery, the voltage drops while the welding pulse initiated, which doesn't supply enough voltage for the N channels, they become high resistance, then overheat and fail. If you use strong enough battery, these won't happen. You are supposed to use minimum 60C 5Ah battery - which means minimum 300A capable battery. The one used in the video definitely can't do so.
@@AdamWelchUK You could remake it using an arduino with your skills very easily. More mosfets would help, maybe add an extra layer, as would bulking the main tracks with lots of copper "rebar" to carry and distribute the current more evenly and effectively. Thanks for taking one for the team!
You had the same problem I had on my first attempt. The 12V input source dropped and did not provide enough gate voltage for the switching FETS. The FETS did not get to or remain at their low resistance state and dissipated a huge amount of power, overheating them. The FET internal silicon melts internally and shorts out. I solved this by using a separate 12V supply to power the board and connected the positive welding probe to it's own high current 8-12V separate source. The negative welding probe is fine connected to the normal board connection. Connect the high current negative source to the normal board connection as well. I am using 3 3000F supercapacitors in series (8V) for the welding power source. The board works fine for me with only three of the original power FETS.
Absolutely no. Those welders are awesome. The main fault is of the operator. Because if you use a week battery, the voltage drops while the welding pulse initiated, which doesn't supply enough voltage for the N channels, they become high resistance, then overheat and fail. If you use strong enough battery, these won't happen. You are supposed to use minimum 60C 5Ah battery - which means minimum 300A capable battery. The one used in the video definitely can't do so. Another modification can be done - search Maker Fabio's videos. He explained this and suggested a modification.
Yep, that's what I've seen too. Weak battery and you get smoke. Instructions say you need a battery with at least 50ah, I think, so a car battery with ~363 CCA (50 x 7.25). CCA / 7.25 will give you a close estimate of the AH of a car battery.
Diddos...and I even went through a dual makita battery rebuilt(with solder ::smh::). Still holding albeit a bit fat around the waist (bulge from solder lol)
@@Flav_M Or it might be a good idea to hack it as soon as you get it and fix the solder on the mosfet run so it doesn't smoke...and try to start small rather than hit it so hard it burns a hole in your desk (good to know it has the oomph to actually spot weld alot...because boy howdy did it ever!)
@@haydenc2742 We really ought to shift this way of approach. We know if we bark loud enough we can get a decent product. If I have to set up the solder station I might as well detach them all and replace with proper ones. I just did this to the switches of my EXACTLY 1yr(you guessed it, 1yr warranty, and we f'n accept this as normal) old Logitech G502 mouse. Glad I looked into it... well known issue, across multiple brands, something I have adequate skills for. So I did them both(obviously) which resulted in a working part going in the bin. This is probably why there's plastic in our food. Oh I went off the rails there. My bad, have a good day ✌:).
You might as well go to your local scrap yard(unless you have one at the ready) and pick up a starter relay, since you have the pedal, battery and decent cables. Also been eyeing these for a while, thanks for saving me a few bucks.
Absolutely no. Those welders are awesome. The main fault is of the operator. Because if you use a weak battery, the voltage drops while the welding pulse initiated, which doesn't supply enough voltage for the N channels, they become high resistance, then overheat and fail. If you use strong enough battery, these won't happen. You are supposed to use minimum 60C 5Ah battery - which means minimum 300A capable battery. The one used in the video definitely can't do so.
Thanks for sharing. I was both sceptical and hopeful as you began. I saw looking for a welder, for use on 18650s, and I guess I will continue that search.
Those welders are awesome. The main fault is of the operator. Because if you use a week battery, the voltage drops while the welding pulse initiated, which doesn't supply enough voltage for the N channels, they become high resistance, then overheat and fail. If you use strong enough battery, these won't happen. You are supposed to use minimum 60C 5Ah Lipo battery - which means minimum 300A capable battery. The one used in the video definitely can't do so. Another modification can be done - search Maker Fabio's videos. He explained this and suggested a modification.
Adam, I think you killed the welder as a result of your old battery. These welders require a strong, fully charged battery capable of delivering the current & keeping voltage high enough. This blown FET issue is very common with these, and some people have discovered a fix by adding a cap AFTER the diode that powers the FETs. The cap keeps around enough energy to keep the FETs fully turned on, and not in the resistive state where they burn a lot of energy. Adding this cap and/or using a nice and beefy high C-rate LiPo would've likely let the welder work a treat. and not kill itself.
I had the same problem with the first two that I tried. They failed after the first three weld. I received the third one and decided to used some lithium ion battery 4-in series (yuasa LEv 46) but they were halfway charge so the voltage was around 14v. The third spot welder works perfectly, After I decided to try the ones that blow up with this new battery and they work fine, even the first one that caught fire. I could be wrong but the problem seems to be voltage drop once the dead short happens for the weld.
Nice video! Regarding the failure there is mod you can do to maybe prevent this. You connect a capacitor on the control circuit to be sure that MOSFETs are full saturated even if battery voltage is a bit low.
Do you think? I always find that the title that gives away the punch line is always a bit disappointing. I should use more click bait running up to Christmas ;-)
Awwwww man! I was really hoping this would be a nice bit of kit, as I've nearly brought one a few times... Kinda glad I haven't now!! Still want one tho...
€ 7,74 8%OFF | Diy Draagbare 12V Batterij Vlekken Lasser Pen Model Pcb Printplaat Controle Lasmachine 18650 Energie Opslag Spot Soldeer a.aliexpress.com/_BT4I1L this one works y have one and IT works like crazy y used a 54 amp lead accid battery .to power the PCB
@@AdamWelchUK I read a number of these units have been dying in user reviews when I looked, same thing FETs detonate. The units with the in-built lithium batteries seem to fare better, possibly due to the low voltage (1S, 3.7V) used. I imagine the output loop on these is nice & inductive and that ~500A @ 12V pulse would likely cause an inductive spike that exceeds the VDS breakdown voltage of the MOSFETs and short the FET permanently. Probably needs MOSFETs with higher VDS voltage.
Have I missed the point wher the foot switch get attached to the welder? I'm looking specifically for a video how to attach the foot switch to the welder. 🤔
The welder has a barrel jack connector which is the external manual trigger. You could attach a foot switch or any other type of momentary switch to this connector.
I've have one of these exact units and it's very good I'm very happy with it the only issue is the size of the end of the tip it's a bit big but no problem just filed it down
Yep , mine blew up as well - only it let a lot more smoke out . To be fair the suppliers have sent me more mos fets , but it looks a bit fiddly to solder them in. I am now constructing a welder using a 200amp auto relay , I might see if I can use the timer function from this device to control it.
this happened to mine on the first weld,i replaced the fets (all were sc),added a cap+ diode on the microcontroller supply,been fine since (about3years ago+ lots of welds),i use a 30ah car battery but always charge it before using it on the welder,it also works for blowing away dendrites on nicad cells too!.
im wondering if the foot pedal was on for too long. the auto function should shoot the current for half a second max usually even shorter time. should have first used it as it came from the box in auto mode.
Absolutely no. Those welders are awesome. The main fault is of the operator. Because if you use a weak battery, the voltage drops while the welding pulse initiated, which doesn't supply enough voltage for the N channels, they become high resistance, then overheat and fail. If you use strong enough battery, these won't happen. You are supposed to use minimum 60C 5Ah Lipo battery - which means minimum 300A capable battery. The one used in the video definitely can't do so. Another modification can be done - search Maker Fabio's videos. He explained this and suggested a modification.
cnx-software wrote an article about this unit linking to an other yt video. There is a warning that the controller needs a cap to work properly. (tldr don't burn your IRL40SC228CT because of voltage drop )
It doesn't need a capacitor if your power supply can supply a literally infinite amount of energy without voltage drop. These poxy old Lead Acid batteries had zero hope of providing enough current
Hi Adam. How to say this polite. It is good to see I am not the only one that blows stuff up on first try. It also happens to the best 😁. Of course bad luck the thing started smoking. I would have done exacly the same. Asumjng the device would protect it self from buring out.
It probably means that you have to manually press the switch. Auto would initiate the weld when it detects low resistance between the probes. At least that's how it works on the much less dodgy kWeld.
A good question but I’m fairly sure I had the foot switch engaged for longer than the current was flowing (although I’m fairly sure that it was flowing longer than my suggested 10ms). I’m interested in looking a little further at this unit and that’s something worth checking out. Cheers Julian.
They are good but you must modify them (some of them anyway) before use. Adding a 16v 1000uf capacitor helps with voltage drop to the drain which causes the mofsets to fail. Beefing up the solder traces with copper wire also helps. To use these stock you must use a 100ah or above battery.
I Bought one like that, it didnt make a single weld, it blew up, and caught fire for a few seconds, it's the second one that did that! I don't see them working long, if they do work!
Absolutely no. Those welders are awesome. The main fault is of the operator. Because if you use a week battery, the voltage drops while the welding pulse initiated, which doesn't supply enough voltage for the N channels, they become high resistance, then overheat and fail. If you use strong enough battery, these won't happen. You are supposed to use minimum 60C 5Ah Lipo battery - which means minimum 300A capable battery. The one used in the video definitely can't do so. Another modification can be done - search Maker Fabio's videos. He explained this and suggested a modification
Just what I (didn't) need to watch with an Aliexpress order somewhere along the delivery process to me, but not a spot welder. I've been ordering like crazy off them and Banggood as the end of the year and import duty approach and this is the final bag of goodies still on the way.
i got the same welder 2 weld one mosfet blew up removed it and it did 50 more welds then another mosfet blew it now has only 3 of them in and is working great so far with 300 welds under it belt :-) those mosfets are 400amp ones so even with three a small lawnmower battery with max of 325 cca works great on it. I did order new mosfets from china and waiting for them to get here, They are real cheap :-) its two mosfets in each package hence the 6 leads on each one
I had the same spotwelder it broke the first time i use it lol Maby my automatic function is broken now i will try a foot switch and see id it still works
I want to ask about this machine. I bought it from the market and started to weld it, but it does not weld well. I used a 12 volt 7 amp dry battery. What is the reason? I hope you will give me an answer to that. Thank you.
I have a feeling you could pop off the damaged mosfet, widen out the solder blob, and carry on using it like that, just staying away from the higher power settings. That fet in particular might have been weaker than the rest, or like you said carried most of the current thanks to the incomplete solder job on that trace. Either way it's basically a free repair, so it's worth taking a shot.
Mine let the magic smoke out on setting 40 and using a 4s lifepo4. Stick to 3s lipo. Also connect the two red leads to the same screw terminal to avoid dragging all of the current across the entire length of pcb tracks.
@@AdamWelchUK I took a grinder to the first mosfet that blew. Ground through the shorted semiconductor layer. The device came back to life... sort of. The rest died the same way... genuine replacement Fets are $5 each so the ones on these boards are likely rejects or clones.
Nice video. Thank you! I would try to repair it and for good measure add plenty of solder on all those mosfets. Perhaps you can even add a second layer of mosfets to split the power that goes through them...
Those welders are awesome. The main fault is of the operator. Because if you use a week battery, the voltage drops while the welding pulse initiated, which doesn't supply enough voltage for the N channels, they become high resistance, then overheat and fail. If you use strong enough battery, these won't happen. You are supposed to use minimum 60C 5Ah Lipo battery - which means minimum 300A capable battery. The one used in the video definitely can't do so. Another modification can be done - search Maker Fabio's videos. He explained this and suggested a modification
Looking at 11:32 - what is the current-limiter? The R_ds_on of five FETs in parallel? They prolly don't expect you to put a beefy 12V car-battery as the source...
hi adam big fan i have a question about your epever dashboard , i am setting up my own for my epever UPower inverter charger . i am using ubuntu, python, influxdb, grafana and everything work fine except for the 32 bits register conversion, for example PVwatt is split in two 16 bit data high and low . i noticed that you did a bit of program to solve this issue , i hope you can share your solution . thank you adam
I have an ATX computer PSU that I modified to have a 12v output. Will that work with this welder? Since the ATX PSU is running off of wall power, would I have the same issue with the voltage drop?
Hi Adam, good review. I followed your links on this and the update video but they don't go to a specific item on Ali express and the search terms don't bring a result either.
Ever Video I watch this same thing happens. Some suggest a mod to make it work better. Wonder why the maker of these don't make the mods before saleing them. I bough one last week and it burnt out on the second weld.
Single Use Chinese Smoke Generator... some assembly required. They really can't get some battery / high power stuff right for cheap... Have a KSGER lithium soldering iron and the balancer board trashed one of the cells, currently testing if the replacement board is any better.
If the small battery cannot maintain voltage under load, the microcontroller may reset in mid-pulse, extending the pulse until the FET enters thermal runaway.
It's easy to say for me since I have a kWeld and have spotwelded before, but from the first second I saw this device I knew it wasn't going to work well. I could tell be the look of that thing that it's just way too flimsy for what it's supposed to do, which is handling hundreds or even thousands of amps. I didn't anticipate it to blow up immediately though, that was a surprise :) And by the way, I don't think that this is supposed to work with any battery really. The cap is merely a hold up cap for the microcontroller and display to continue working when the voltage drops during the short circuit. It's not a power cap to deliver the current for the actual weld. Oh, and yes, you need a heat resistant surface when you aren't actually welding cells because, yeah, you've seen why :) I suggest you take a look at the kWeld. And the optional Power Cap Module for when you want it to work with almost any battery or power supply / DC-DC converter / charger of some kind to charge the caps. Otherwise you will likely need a bigger lead acid battery than the one you've tried here (or several of them in parallel) or a decent quality LiPo. Happy welding! :)
I may have missed it but at these prices these devices have current limits, maybe you should have took some precautions first. I would love to see this device work for us cheapskates. Nice video.
Oh man. I bought one of these a few weeks ago but haven't had a chance to try it yet. The reviews and videos are mixed. Sometimes they work sometimes not. The trouble is these designs get ripped off all the time in China so there could be one manufacturer that is actually making a good product but there may be a dozen mediocre or downright horrible clones. For us hobbyists who buy from eBay, Banggood, Aliexpress or others there's no way to guarantee the providence of a product. Even multiple purchases from the same seller on eBay/Banggood/Aliexpress could have mixed results. The sellers may A) not care B) not know which of their suppliers are legit. Anyway I have one and I'll give it a try. If it goes poof on the first weld I'll thrown in the towel and get a kWeld. (Which is probably what I should have done all along.) Thanks for the video.
Thanks! kWeld it is then :) Choose a proper MOSFET :) I looked at them & saw that I won't be able to tell how much power I put in a weld. And knew that the only way they can make it so cheap is to use solder as a conductor so I would need to solder some offcuts of a solid copper cable. Now I see it is even worse - a Chinese MOSFET released the magic smoke.
These all have a fatal design flaw where if the input voltage drops too low during the weld the MOSFETs clamp and never receive enough signal to open and they burn up. Usually one or 2 take the brunt of it and if you replace them you are back in business after adding a decent-sized capacitor to the mainboard to allow the circuity enough voltage to break the circuit even if the battery voltage drops too low. I have been through enough of a few of the different models of these and with lipo batteries, or super caps they seem to work ok at the start while the voltage remains high but as the battery goes low they reach a point where they then clamp, burn up and fail.
There’s a fella on Project Evolution that does some DIY mosfet spot welders that perform pretty dam well, maybe there’s some info on his channel you could see to beef this spot welder up.
Unfortunately, this is a well documented issue. You did not have a strong (or well charged) enough battery, and the voltage drop resulted in the mofsets not being saturated and it collapsed. I expected this to happen when you showed 12.6 volts, which is quite a bit below full charge. There is an excellent RU-vid video which shows an easy modification by the addition of a capacitor to protect against this blow-out situation arising. It is a great little welder but you need a fully charged and sufficiently strong battery with plenty of amps and voltage.
lead acid batteries will lose charge over time that's why if you dont plan on driving your car for a while you need to have someone drive it for a few minutes to recharge the battery. lithium batteries do not self discharge as much unless the bms is faulty or of older design that does not go into sleep mode to save power. anything above 50 and you will destroy the unit especially if you dont make the modification of a capacitor between a diode and ground on the fets.* they recommend use below 30 . the problem with damage caused by going above 50 is that when the battery drops in voltage the fets are no longer saturated and overhead and blow.* *= according to another youtube videos.
Mosfets in parallel is a tricky subject and I’m not sure there are many out there that can truly handle the full current of the battery. I may revisit this device one day.
@@AdamWelchUK I bought the cheapest at Ali, and it is working just fine. I use a small 12Volt battery and 6 supercaps in series. The device has 3 or 4 levels, but i need to use the highest setting for 0.1 mil nickel strip. My unit was only 11 dollars or so and is no more than a pcb and a few wires and a simple push button to set the mode. and a buzzer as well. It sends bursts of power every few seconds, so the foot switch is not needed (but is handy if you can use it). I have not tested yet, but a (high current) capacitor of the correct value will do the job as well.
Should have started much lower instead of the preset 10. I would have started at about 4 or 5. Also auto might detect the current passing through the MOSFET's and shut off the current at a set point. Edit** I would contact the seller with a link to your video to show that it blew a MOSFET after the first use.
I too have recently bought one of those spot welders and the exact same thing happened to me. I can say that it is a good gadget with slight modification and I have enjoyed it for about a week now. According to another video I have seen (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-fdnO0Z-scjA.html) The issue lies with the drop of the battery voltage during a weld resulting in the control circuit not putting the mosfets into saturation. The solution to which was to put a bypass capacitor onto the rails of the control board. After doing this (and charging the battery) the spot welder seems to work pretty well and makes strong welds (while only running on 4 fets but I have of course ordered some replacements).
An easy mod makes these work. Check out Maker Fabio channel. He adds a small capacitor to combat low voltage drops which causes them to explode. Type "maker fabio spot" it comes up.
@@astrolite3192 Actually watch the video. He has a commercial oscilloscope and tests without the add on capacitor... huge voltage drop. Test with added capacitor... No voltage drops more than 1 volt.
@@thisphone5371 Actually find the post somewhere on the net explaining avalanche current, probe inductance, flyback / schotty diodes, oscilloscope levels of flyback current with no diodes, with diodes & the datasheet explaining that the avalanche current levels it ships with ultimately cooks the mosfets. I'm busy...
@@astrolite3192 Wasn't personal. If you want a cheap battery welder, dont give up b4 you try this one. This thing is plagued but delivers results even with an incapable battery. Low voltage safety is just a plus. Mine works fine with no issues after modding b4 first use. Worth a try when using the upgrade.
@@thisphone5371 Sorry, don't misunderstand, I have this welder and am currently running it fully stock. I just mean the people that developed the kweld &/or the other one went over it all on a fourum somewhere with a full explanation (with oscilloscope readings) showing the avalanche current exceeding the rating in the mosfets datasheet. I just don't have time to find it for about a month.
As Dave Jones famously said " I hope it doesn't work, so you can figure it out"..lol I wasn't interested in that one but as strange as it sounds I want one now...
The issue with these modules is that as soon as you weld, the input voltage goes down, thus the gate voltage goes down, thus the on resistance goes up, meaning the fets will get toasty :P If you mod it that the board itself uses a different 12volt power supply, and just cut off the battery voltage to the control module, the module will keep operating as normal
you had me mystified for a moment, we have a car parts chain store in Australia called super cheap auto, and I was wondering why they'd be stocking a spot welder lol
Great video. Like many imports, some instructions would have helped. You've shown why they don't use wooden ladles in Nickel refineries. I hope new fets fix it, maybe need a few though.
do some research online, also read the full description on AliExpress, you chose to use an inadequate Battery, that was your problem, replace the Mosfet, or just remove it, and try a decent battery...
At about 6:36 it was clear that the mosfets weren't going to last the length of the video. Battery way too low current. So many of these tests very unfair to these cheap spot welders. Instructions, bad translations, are quite clear about the power supply. Too low, don't saturate the mosfets so they don't trip.
This guy must have got lucky with his unit ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-OWSmOyh5Gvg.html (also Adam, looks like that battery you had wasn't good for this setup and maybe shouldn't have turned it up to 99 prior to weld... just guessing)
