MrNatural22
?SW sunshine =⚡️⚡️lit up thru the darkness✌️
Simple inexpensive diy spot welder for smaller battery packs. ?
DIY spot welder
- Thread starter MrNatural22
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BarkingSpider
Carbon Lifeform
I just completed mine based on your example. Works great. Handles .15mm zinc no problem.
I used this for the pen and switch from Amazon ($22)
This for a secondary switch that I prefer. ($7)
This relay ($13)
A small old 300a AGM battery from my garage and some battery cables. (Free)
Makes perfect, strong welds for under $45 — thanks for the inspiration!
I used this for the pen and switch from Amazon ($22)
This for a secondary switch that I prefer. ($7)
URBEST Black AC 250V 10A SPDT NO NC Momentary Foot Pedal Switch for CNC Industrial with Anti-Skid Rubber Surface: Amazon.com: Industrial & Scientific
URBEST Black AC 250V 10A SPDT NO NC Momentary Foot Pedal Switch for CNC Industrial with Anti-Skid Rubber Surface: Amazon.com: Industrial & Scientific
www.amazon.com
This relay ($13)
A small old 300a AGM battery from my garage and some battery cables. (Free)
Makes perfect, strong welds for under $45 — thanks for the inspiration!
Hedges
I See Electromagnetic Fields!
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OK, that works.
I see some of you are connecting cells in series, so you're fine.
If anyone wants to parallel cells like in the video, consider fuse per cell strips:
diysolarforum.com
Can you take a shunt or clamp ammeter reading of your welding current?
Current and time would be the parameters to control.
If you have a bad cell to play with, you could determine pull strength vs. spotweld time, make SPC charts and have an ISO-9000 certified factory.
(or at least aim for the middle of the process window.)
I see some of you are connecting cells in series, so you're fine.
If anyone wants to parallel cells like in the video, consider fuse per cell strips:
Thinking about battery backup
Correct, they will be 34 in parallel (2 rows of 17 cells). What gauge wire should i use to connect the 14 in series? 150A draw/34 parallel = 4.4A. Almost any wire will do. The question is what is the best mechanical or other connection method. Is there a way to manually connect busbars to the...
diysolarforum.com
Can you take a shunt or clamp ammeter reading of your welding current?
Current and time would be the parameters to control.
If you have a bad cell to play with, you could determine pull strength vs. spotweld time, make SPC charts and have an ISO-9000 certified factory.
(or at least aim for the middle of the process window.)
BarkingSpider
Carbon Lifeform
To get the right duration, I just practiced welding a zinc strip to a large washer. Just a momentary tap on the foot pedal is enough.
I make lots of Lifepo4 batteries in 12/24/48v formats for testing. It's perfect for that.
Its a 300amp 13v pulse. 4000W!
If your want a bigger weld, simply tap again on the same spot.
Its handy, I've been fixing other things around the house with it, tattoo anyone?
I make lots of Lifepo4 batteries in 12/24/48v formats for testing. It's perfect for that.
Its a 300amp 13v pulse. 4000W!
If your want a bigger weld, simply tap again on the same spot.
Its handy, I've been fixing other things around the house with it, tattoo anyone?
emeraldcoastcamper
New Member
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How do you adjust the current to avoid blowing holes in the tabs and the cells themselves?
schmism
Solar Addict
you typically dont. You vary the "on time" of the momentary switch that you press.
emeraldcoastcamper
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Thanks. I just ordered the three items from Amazon.
BarkingSpider
Carbon Lifeform
It takes some practice, just try it out on some old washers to start. Its old school, but it works well....
emeraldcoastcamper
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BarkingSpider
Carbon Lifeform
Did it all work out ok?
emeraldcoastcamper
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The welding pen arrived today and the solenoid and foot pedal come tomorrow. The pen has two separate plugs that appear to have a push button switch. Of course there are no instructions. Do you know the purpose of these plugs? And what do you do with the barrel connector?
I would appreciate some coaching as to wiring the foot pedal if you have the time to share some wiring instructions.
I would appreciate some coaching as to wiring the foot pedal if you have the time to share some wiring instructions.
Attachments
BarkingSpider
Carbon Lifeform
The key to remember is the welder can be either operated by the pen -or- the foot switch. Just a momentary pulse is still you need.
They are both wired in parallel as in the photo below.
If I could only use one method, I would use the foot switch.
The extra micro switches that come with the pen are just spares.
Push down on the pen nibs on a hard surface and you can hear it operate.
Doing so just closes the circuit on the 2 smaller wires.
Is very simple, it just looks a little complex with all the wires. Both switches use red and white wires.
In my version, white wires go to positive on battery, red goes to the solenoid.
When the foot pedal or pen is pressed, power is sent to the solenoid, closing the main circuit on the large wires for the weld.
Is easy to test, just push the pedal, or push the pen on a non conductive surface (ie wood or plastic) and you will hear the big solenoid click into action.
Let me know if you have any other questions.
They are both wired in parallel as in the photo below.
If I could only use one method, I would use the foot switch.
The extra micro switches that come with the pen are just spares.
Push down on the pen nibs on a hard surface and you can hear it operate.
Doing so just closes the circuit on the 2 smaller wires.
Is very simple, it just looks a little complex with all the wires. Both switches use red and white wires.
In my version, white wires go to positive on battery, red goes to the solenoid.
When the foot pedal or pen is pressed, power is sent to the solenoid, closing the main circuit on the large wires for the weld.
Is easy to test, just push the pedal, or push the pen on a non conductive surface (ie wood or plastic) and you will hear the big solenoid click into action.
Let me know if you have any other questions.
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emeraldcoastcamper
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emeraldcoastcamper
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Thanks for the reply. So why do you need the solenoid?
BarkingSpider
Carbon Lifeform
The switches are lower power circuits that operate the solenoid for the high power circuit. Just like any relay.
The full current rush for the welder is too high and would melt the little switches in the pen or footpedal. The solenoid can handle that power with a much larger contact surface.
The full current rush for the welder is too high and would melt the little switches in the pen or footpedal. The solenoid can handle that power with a much larger contact surface.
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emeraldcoastcamper
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I don’t know why I am not comprehending this. Have wired plenty of 12 relays byt they were all in a 110V configuration.
From what I can read the welding pen should activate without a switch and it does indeed when connected directly to my battery...just way too much juice. Please tell me what to do based on the way I have this connected. There is 12.5 V at the battery terminals. Battery + to right pole of solenoid. Battery - to welding pen. Left side of solenoid to welding pen. I do not see a - or + on the pen.
From what I can read the welding pen should activate without a switch and it does indeed when connected directly to my battery...just way too much juice. Please tell me what to do based on the way I have this connected. There is 12.5 V at the battery terminals. Battery + to right pole of solenoid. Battery - to welding pen. Left side of solenoid to welding pen. I do not see a - or + on the pen.
Attachments
BarkingSpider
Carbon Lifeform
I will draw you out a circuit diagram, give me a moment ....
The small wires from the pen are for operating the solenoid, polarity is not important.
First get the solenoid working when you press the pen down.
Then connect the high power circuits afterwards.
The negative pole on the solenoid is shared with the power and switch circuit, you only need to attach the positive wire to operate the solenoid.
Look at my photos, all the info you need is there, it's much simpler than you think.
The small wires from the pen are for operating the solenoid, polarity is not important.
First get the solenoid working when you press the pen down.
Then connect the high power circuits afterwards.
The negative pole on the solenoid is shared with the power and switch circuit, you only need to attach the positive wire to operate the solenoid.
Look at my photos, all the info you need is there, it's much simpler than you think.
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BarkingSpider
Carbon Lifeform
Solenoid details
The 2 red wires are momentary power from my 2 switches. When these are live ( you press the pedal or pen), the solenoid will close and send full power to the pen.
The 2 red wires are momentary power from my 2 switches. When these are live ( you press the pedal or pen), the solenoid will close and send full power to the pen.
emeraldcoastcamper
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emeraldcoastcamper
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Wow. Thank you so much and I will need this...when I get a new solenoid. I should have tested it first especially with such a banged up box. I put 12 Volts to it and no click. I further tested for continuity at the load terminals and found none. So returning this one to Amazon and waiting for a replacement.
Newbie question coming. Does the solenoid have to be grounded for this application? It appears that you have attached the grounding plate to the neutral side of the battery.
Newbie question coming. Does the solenoid have to be grounded for this application? It appears that you have attached the grounding plate to the neutral side of the battery.
