Welding machine for Lipo Cells

[999zip999]

Don't forget to have weilding goggles. As you don't look into the sun.

 

[Giovanni LiCalsi]

What is the price?

 

[Spacey]

I have contacted the German guy to buy his battery welder...but no reply.

 

[agniusm]

What is the price?

Something like 7k $

 

[mistercrash]

Would anyone in this forum care to inform everyone else on a very good capacitive discharge battery welder (double pulse would be awesome) that a newb like me with not much money can buy for under 600 dollars? Is it possible that there is a CD spot welder out there at that price that can bring many years of good service on a hobby level? If you know please share it with me because all I can find that looks good enough is in the $2000 and up category.

 

[Jonathan in Hiram]

Would anyone in this forum care to inform everyone else on a very good capacitive discharge battery welder (double pulse would be awesome) that a newb like me with not much money can buy for under 600 dollars? Is it possible that there is a CD spot welder out there at that price that can bring many years of good service on a hobby level? If you know please share it with me because all I can find that looks good enough is in the $2000 and up category.

There's a lengthy thread on making your own capacitor discharge spot welder on ES from a few years back, all the information you need is there and the actual circuit is remarkably simple, you could build one easily for under $200 and probably under $100 if you are at all a resourceful scrounger.

Use a car audio capacitor, Monster Cable brand, Rockford Fosgate or another brand I can't recall, the rest of them are not all that good with often extremely overrated specifications.

I have the parts ordered for a unit but they haven't all arrived yet. After I have my unit put together and get a couple or three packs welded up I probably won't have much use for it and might be interested in selling it.

The thread is here, I would strongly recommend that you read the entire thing, there's a lot of good information there on building and using a spot welder for battery tab welding:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=2633


And this is the circuit diagram by Jeremy Harris, note that the second 8 ohm 5 watt resistor to the right of the SCR symbol has been deleted since it caused problems and the circuit worked better without it.

 

[circuit]

Dont know about you guys but i like this machine:
[youtube]m86qwHKGXZc[/youtube]

Very neat welder. Looks like a scaled-down and well automated TIG.

By the way I do have a spot welder with two "audio" 1.5F 12V caps, 10 300-amp mosfets, proper driver and laboratory PSU and huge 50mm² wires to electrodes... It does the job, but is not very user-friendly, requires some better mechanics.
But those caps are no good. On my next build, I'd use Maxwell's ultracaps instead.

 

[mistercrash]

There's a lengthy thread on making your own capacitor discharge spot welder on ES from a few years back, all the information you need is there and the actual circuit is remarkably simple, you could build one easily for under $200 and probably under $100 if you are at all a resourceful scrounger.

Use a car audio capacitor, Monster Cable brand, Rockford Fosgate or another brand I can't recall, the rest of them are not all that good with often extremely overrated specifications.

I have the parts ordered for a unit but they haven't all arrived yet. After I have my unit put together and get a couple or three packs welded up I probably won't have much use for it and might be interested in selling it.

The thread is here, I would strongly recommend that you read the entire thing, there's a lot of good information there on building and using a spot welder for battery tab welding:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=2633


And this is the circuit diagram by Jeremy Harris, note that the second 8 ohm 5 watt resistor to the right of the SCR symbol has been deleted since it caused problems and the circuit worked better without it.

Thanks for your informative response. I haven't read the whole thread but I hope I find the time to read it all and take some notes. The OP of that thread is I think this guy here. http://ledhacks.com/power/battery_tab_welder.htm He did a first CD welder than a second version then a higher voltage version and finally combined all of them to have a dual pulse CD welder. Pretty cool stuff. So your post answers my question, there's only two options to have a good reliable CD welder, either make it yourself for cheap or spend a fortune on something like a Sunstone. Anything else looks like rubbish. Thanks again.

P.S.: I can't read a circuit diagram, that's how ignorant I am. A good reason why I would've preferred to buy a welder and learn to use it rather than risk hurting myself building one, but it is my only option.

 

[Hillhater]

For a hobbyist it would seem logical to go with the $150 chinese welder and gamble on it lasting a few hundred welds.
Even If it did fail, it has to be simpler to fault-find /repair (upgrade) a functional m/c rather than build something from scratch ?

 

[bigmoose]

Just a thought about the parameters for welder selection. These welders and the battery spot welds are rated in watt-seconds delivered to the welds. To know what will work, we need to know the watt-seconds for a successful weld, then we can look at alternate weld machines and/or building our own welders. As said above member texas pyro developed a good welder IIRC a few years ago.

 

[Jonathan in Hiram]

For a hobbyist it would seem logical to go with the $150 chinese welder and gamble on it lasting a few hundred welds.
Even If it did fail, it has to be simpler to fault-find /repair (upgrade) a functional m/c rather than build something from scratch ?

Normally I would agree but Jeremy's spot welder is brilliant in its simplicity.

Other than a car audio capacitor and a variable power supply that goes to about 19 volts, this is it, there's only three parts in that box and only one of them is more than five bucks or so.

 

[Jonathan in Hiram]

Just a thought about the parameters for welder selection. These welders and the battery spot welds are rated in watt-seconds delivered to the welds. To know what will work, we need to know the watt-seconds for a successful weld, then we can look at alternate weld machines and/or building our own welders. As said above member texas pyro developed a good welder IIRC a few years ago.

It works out to a Farad or two at fifteen volts plus/minus depending on conditions and efficiency of the rest of the circuit, it's an easy one to get a lot of losses in since it's very high current (~1000A), total circuit resistance in the single digit milliohms. With more capacitor you can use lower voltage and still deliver the same energy to the weld site.

Two hundred Joules actually delivered to the welding site(s) sticks in my head but I've been looking at a lot of different things related to this lately so I could be wrong.

 

[Hillhater]

but Jeremy's spot welder is brilliant in its simplicity.

Other than a car audio capacitor and a variable power supply that goes to about 19 volts, this is it, there's only three parts in that box and only one of them is more than five bucks or so.

It seems like this is a basic tool we all should be using... but....
That 40 page thread goes round in circles and off in numerous tangents :?
Could someone do a simple listing of parts and summary of this build. ?

Better still, someone should put these together and offer them up for $50 -$100 a piece !

 

[Jonathan in Hiram]

It seems like this is a basic tool we all should be using... but....
That 40 page thread goes round in circles and off in numerous tangents :?
Could someone do a simple listing of parts and summary of this build. ?

Better still, someone should put these together and offer them up for $50 -$100 a piece !

A 40 page thread that ~didn't~ go round in circles and off on numerous tangents would probably make internet history.

That's a potentially somewhat dangerous device to be offering up for sale, the liability exposure for a kit is probably less than for a finished unit.

 

[silviasol]

Would anyone in this forum care to inform everyone else on a very good capacitive discharge battery welder (double pulse would be awesome) that a newb like me with not much money can buy for under 600 dollars? Is it possible that there is a CD spot welder out there at that price that can bring many years of good service on a hobby level? If you know please share it with me because all I can find that looks good enough is in the $2000 and up category.

There was a guy here in the US that was selling these and had good feedback for them other then some people complaining the cords are too short

http://www.ebay.com/itm/110V-Hobby-Mini-Battery-Tab-Spot-Welder-Custom-Built-Machine-for-Small-Projects-/151197460025?pt=BI_Welders&hash=item2334122639

 

[parabellum]

This hobby tab welder is not capacitive type.

 

[Punx0r]

Perhaps an ignorant question, but does it need to be?

Not for batteries, but of the commerical single-sided spot (poke) welders I've seen the transformers ones perform as good as, or better than, the cap ones. I think it was stainless rather than nicel strip we were using, but similiar dimensions to small battery interconnect strip and welded to steel plate.

 

[mistercrash]

Better still, someone should put these together and offer them up for $50 -$100 a piece !

I'd buy one right now.

That's a potentially somewhat dangerous device to be offering up for sale, the liability exposure for a kit is probably less than for a finished unit.

And here comes the lawyers :lol: Seriously, and sadly I have to agree. Did Jeremy Harris start a thread to show his welder or was it part of another thread, I searched but couldn't find it.

How about a kit to assemble? If something happens, you can always blame the user for assembling incorrectly.

The transformer welder does work according to many but I don't understand how that red glow at the welding point is better than a soldering iron.

 

[Spacey]

Just bought some 5F Super caps and all the other kit to build one. Will gut my Chinese crappy pulse welder and hook this bad boy up inside the case

 

[Hillhater]

Just bought some 5F Super caps and all the other kit to build one.

Any chance of a "shopping list" ..??
..and specifically a cheap source of the 1F power caps that seem to be all up near $100 !

 

[Melbourne]

Just bought some 5F Super caps and all the other kit to build one.

Any chance of a "shopping list" ..??
..and specifically a cheap source of the 1F power caps that seem to be all up near $100 !

Currentlt at AU $89.00 pickup Adelaide, South Australia, Australia

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=321288010029&ssPageName=ADME:B:WNA:AU:3160
Battery Spot Welder Welding Machine with Battery Charging Capability & Foot Pedal Features & Specifications: • Unique digital battery recharge function for constant current/constant voltage recharge if you are out for work. • Advanced MCU current controller achieved precise micro-computer soldering. • Soldering Thickness: 0.1~0.5mm • Wider current range and single/double pulse soldering mode selection perform powerful function and high reliability. • MCU start control. • Touch digital control with temperature display has precise spot soldering. • Battery recharge LED display 2 X 3 digits. • Short circuit protection in recharge output. • For assembly soldering all kinds of mobile battery, notebook battery. • Also for precision processing soldering metal parts. Voltage Input: AC 180V~240V Primary Current: 2A~15A; Soldering Current: 50A~800A (Related Pulse Range 1ms~19ms) Soldering Thickness: 0.1~0.5mm Dimensions: 140X245X200 mm Net Weight: 4.3 kg Accessories: Foot Pedal, soldering electrodes, hex wrench, specialized wrench, charging wire, fuse Charging Capability: Voltage Recharge Range: 4.2~15V Current Recharge Range: 0~2A Delivery to purchaser at cost - varies dependent on location, or local pickup available.

 

[agniusm]

Could someone elaborate on differences between CD and transformer based DIY welder? The web is full of both but which one is better and why?
Thanks

P.S. Here is DIY pulse discharge welder:
[youtube]2PPvtOW3Xpk[/youtube]

 

[circuit]

Could someone elaborate on differences between CD and transformer based DIY welder? The web is full of both but which one is better and why?
Thanks

Depends on complexity of the device. If we are talking about primitive DIY welders, then capacitive is better. I have them both. Here's my transformer spot welder (MCU controlled):
http://circuit.lt/?section=projektai&page=welder

I don't have a picture of capacitive welder, but it is made of two "car audio" 1.5F caps, 10 massive mosfets, proper driver, etc.
The main problem with transformer-based welder is that you get a minimum pulse length of 10ms (one half-period on 50Hz outlet), which is often too much. So you have to keep current low and this leads to more heating than actual welding.
And the main problem with cap-based welder is that you need a LOT of capacity and very low Ri to do proper welds. And MCU control, of course. Good caps and mosfets add up to much higher BOM cost.

 

[agniusm]

Sure we are talking about diy, I have pointed it out. The question is to what extent? I notice smaller welds on diy CD welders vs. Transformer based. In theory larger welds- more surface area but again, no one knows how good are those larger welds from transformer welder. So summing up what would be desired voltage/current/timing for satisfactory weld? Theoretical?

 

[circuit]

Another problem with transformer-based welder is that it tends to blow up craters in the material. Maybe it's a mechanical issue, but that is my experience.
We tend to see bigger welds from transformer-based welders because it is a lot harder to achieve with CD at the same hobby budget. Transformer-based welders are preferred by DIYers because it is dead-simple to make, like an American muscle car: just throw a lot of weight at it and you're good to go. CD on the other hand requires some real knowledge and attention to details.