DIY Arduino Battery Spot Welder

Due to many of the requirements for cucsi, there are indeed some PCB sets and pre-built kits in stock at the moment.
Take a look here: Arduino Nano spot welder for battery welding this spot welder can be used to weld 18650 batteries.
It uses a 12 Vcar battery as a welding power supply.
Typically, a 40Ah Astra battery provides enough current to get a good weld of 0.
15mm nickel bars, 0.
25mm nickel bars.
For thicker nickel bars, you may need a bigger battery or two.
The welder generates a double pulse, and by default, the first pulse is 12% of the second pulse.
The rotary encoder can adjust the pulse time of the main pulse and display it on the screen in MS, so you can adjust the time accurately.
By default, it goes from 1. . . Adjustable 100 MS. (
Up to 500 MS in the system menu)
Watch the video for detailed instructions on how to use it.
Project documents :(
BOM, pcb File, aluminum template, arduino code. . . )01. 2018 (V3. 2)Update 12. 2017 (V3. 1)Update 09. 2017 (V3)
Spot welding machine New Version 3 released.
Improvement of V3: update 08.
2017 with a small module, you can power the spot welder directly from the car battery, instead of using a separate power supply.
For more information, see Step 9 in Instructure or my blog. Update 05. 2017New V2.
2 offers some pcb improvements and new \"auto-wiring\" features.
03 Read more updates.
2017 spot welding machine New PCB layout!
V2 improvements: you can find the Eagle/KiCad file for the pcb on my Github.
The easiest way for previous versions is to order the board at the PCB manufacturer.
In Safeway, for example. com .
There you can buy 10 planks for about 25 euros.
V3 is a bit expensive because the mosfet board needs to be made with a 2 oz copper layer.
Order the required gerber files at Safeway.
Com can be found in my Github.
You can sign up through this link to support me, you can get a $5 coupon for your order, I can get a certain order discount in the upcoming project.
But if you like diy, you can also make it on the prototype PCB board with manual wiring.
I am the first prototype of spot welder v1 to do this.
In the photo you will see a made Board look cleaner.
Many people ask how to order PCBs.
So here\'s a small note.
Order the new V3: for version 3 you will need to order the Mosfet and Arduino board separately as the Mosfet board will require a 2 oz copper layer.
Arduino boards can be ordered with standard 1 oz copper.
The size of the 2 boards is the same (50mm x 60mm).
Ordering tutorial :(pcbway. com)(V3)Just go to (
This is the \"PCB instant quote\" tab on their website)
Type BoardDimension (50mmx60mm)and quantity (cheapest is 10).
The rest of the options for the Arduino board do not need to be changed.
Of course, you can change the color of the welding mask (board colour)
Or screen printing (
Text on board)
What do you like.
This does not affect the price.
You can see what it should look like in the photo.
Then click quote now, select your favorite shipping option, and then click add to basket \".
You are now required to add the gerber file.
Use arduino_board _ v3.
From my Github.
The process needs to be repeated to order the Mosfet board, but now select \"2 oz copper layer \".
All other options can be kept the same as the Arduino board.
Use moset_board _ v3. zip this time. (V2 or 2. 1)Just go to . (
This is the \"PCB instant quote\" tab on their website)
Plate size type (100mmx60mm)and quantity (cheapest is 10).
No changes are required for other options.
Of course you can change the color of the welding mask (board colour)
Or screen printing (
Text on board)
What do you like.
This does not affect the price.
You can see what it should look like in the photo.
Then click quote now, select your favorite shipping option, and then click add to basket \".
You are now required to add the gerber file.
Use spot_welder_v2_gerber.
Zip or spot _ welder_v2. 1_gerber.
From my Github. (
For older versions only: You can also order each motherboard on your own using arduino _ board _ gerber.
Zip and mosfe_board _ gerber.
From my github. )
After clicking Submit Order now, the person at Safeway will check if the gerber file is OK.
It may only take a few hours, but it may also take a few days depending on how busy they are.
In Spot_Welder_V2_Gerber.
The Zip Gerber file has \"Mosfet\" pcb and \"Arduino\" pcb on one PCB.
So, ordering 10 pieces means you have 10 full sets.
When you receive the plates, you have to cut them in half in the middle line.
Most of the parts used by this welder are three-hole parts.
Only about 1206 SMD parts are used and the smaller ones are rarely used.
So it\'s easy to weld.
If you buy the parts, I suggest you order more smd parts because these little things will disappear on the floor if you are not careful.
List of materials and trade.
I used about 1206 SMD parts and other sizes to keep the pcb size the same as the previous V2 version.
To weld this SMD part, I think this is the easiest way to place some welding on all pads.
The SMD part is then held in its position with tweezers and welded on one side.
Now the parts are left in place and you can weld the other side.
Now, alternately heat both sides, the solder will automatically pull the part to the correct position.
Note the polarity of SMD diodes (See pictures).
If they place it in the wrong way, it will not work or it may cause damage.
It is very direct to fill the rest of the permeable parts.
Start with small flat parts, all the way to larger parts.
You can see this in the picture.
The new mosfet pcb can use the aluminum part instead of u-The wire is bent 16 mm².
This makes it easier to make because you don\'t need high power soldering iron and a lot of solder paste.
You can still use u-
Instead of the forming wire of the aluminum part.
The template for the alumni section is on my Github.
Aluminum part templates, or if you would like to purchase a ready-made aluminum part, check it out here: malectrics.
EuFirst soldered 8 small tvs diodes to the top of the pcb. (
No longer needed on V3. 2 and newer)
Then unscrew u.
Connect the molded aluminum piece to the pcb with m2. 5x8 or m2.
5x10 screws and m2. 5 nuts.
Make sure the screw head is on the pcb side.
This is necessary if your srews is a bit long (m2. 5x10).
If you place them the opposite way, they may touch the mosfet later and cause a short circuit.
You can also rivet the parts to the pcb with 2. 4 × 8mm rivets.
Or weld 16 mm² Wire bending to u-shape
The shape of the Pcb.
Now you need to install the mosfet and the straight aluminum section.
To do this, bend the leg of the mosfet to a 90 degree angle with some pliers.
Insert the aluminum part into the mosfet of the pcb using m3x10 screws, m3 nuts and nylon washers.
Make sure to place nylon washers between the pcb and m3 nuts to ensure that they do not scratch the pcb and cause a short circuit.
After that, weld the mosfet leg to the pcb.
Put a lot of traces of the welded pcb mosfet and run to u.
Forming aluminum parts that make these traces harder.
Since you have installed the pin head on the arduino pcb, it is now easy to install the pin head on the mosfet pcb.
Simply place the female head of the mosfet pcb on the female head on the arduino pcb.
Place the Arduino pcb on the table, place the mosfet pcb on it, and weld the pin head. Update 12. 2017 (V3. 1 and later)
4 TVS protection diodes can now be used instead of one.
SMD can be used (5. 0SMDJ13A)
Or through the hole (625-5KP13A-E3).
SMD diodes are powerful enough for car batteries up to 800CCA.
Before installing the aluminum parts, Weld 4 TVS diodes on the mosfet board.
This is much easier than welding diodes after installing aluminum pieces. Update 10. 2017: (V3)
Although the specifications of smd tvs diodes are almost the same as the larger straight-through-hole TVS diodes used in previous spot welder versions, it seems difficult to compete with very powerful car batteries.
There, users using a 800 CCA or a stronger battery reported some faults in the diode.
So I decided to replace the diode with a permeable version, which is a bit more robust.
The BOM for V3 has been updated with a new TVS diode.
Here is how to install it to the pcb: scratch the solder from the ractangle part with a box knife to stop the paint, there are many holes on the pcb, and add some welding to the blank copper in the scratch area.
We need this because the straight through holletvs diodes are a bit wider than the SMD version.
As close as possible to the diode 90 degree bend through hole TVS diode legs and cut them short so the diode can be mounted on the pcb.
Then put some solder on the leg and weld the diode to the pcb.
Weld left first.
Welding the right side when the diode remains in the right position (
Pcb side scratches).
Make sure to use a strong enough soldering iron so you don\'t heat the diode for a long time.
It is necessary to weld the diode directly on the pcb without extension cord.
In this way, it can eliminate the high pressure spikes best.
If you do not want to use the automatic pulse function, the pulse will automatically trigger after touching the nickel band with two welding tips, and you can choose to use the 1 feet switch.
For the first welder, I built it with a simple wooden box and a small switch.
But at the same time, I bought a special foot switch.
For example, you can use any switch that you don\'t have (normally open)
1 feet switch.
It has no current.
You can find the STL file for this case in thingiverse.
Here is a better readable assembly instruction with a picture after each step: Assembly option: case with extension cable assembly option: install directly to the car battery terminal: if you want to power the spot welding machine with a Lipo battery, it is recommended to use a fuse on the positive welding cable.
If the spot welding machine fails and causes a short circuit, you cannot separate the welding tip for whatever reason, which will prevent the lipo battery from burning your house or exploding.
The 300A fuse works well and can handle higher current in a short period of time, no problem.
Search for \"ANL fuse 300\" on ebay and you should find it.
First of all, you need to make an adapter to connect the Lipo battery to the spot welding machine and the fuse.
In my case, the battery has an XT90 connector, so I made an adapter with this connector, two short films of 10 mm² silicon wires and two cable shoes.
When everything is connected, you need to isolate the fuse.
The easiest solution is to wrap it with tape.
But the 3d printed box looks cleaner.
You can find the STL file of the case on Thingiverse.
Other parts required to complete the case: upload new software (V3. 1 or later)
A little complicated.
I did a special tutorial on my blog for the old V3: to upload Arduino code to Arduino, you need to do some preparation.
After installing the Arduino IDE, you need to add two libraries.
\"Adafruit_gfx\" and \"adafruit_ssd306 \".
Install them through the library manager in the Arduino IDE (click: Sketch -
> Including Library-
> Management Library)
Then go to the ssd306 Library folder (
This is usually the case on windows: C: \\ Users \\ Marc \\ Documents \\ Arduino \\ libraries \\ adafruit _ ssd136-master )
And open \"ssd1346.
H \"with text editor \". In the SSD1306.
H you need to define 51 lines (
# Define ssd1306_i2c _ address 0 x3c)and line 69 (
# Define ssd136_28 _ 64).
In the latest versio, it\'s line 55 and line 73.
After changing the code, the code should be like this: Don\'t forget to click save when you\'re done \".
Now you can go back to the Arduino IDE and open the Arduino code from the Github project you downloaded.
Connect the Arduino Nano to your computer using a USB cable, and it should automatically install the driver for the Arduino Nano.
If it is not connected, check that this site Arduino is connected properly and a new Com port should appear under the \"tools\" of the Arduino IDE
> Port select the new Com port.
Selct as Board: \"Arduino Nano\" and processor: \"ATmega328\" finally click \"sketch-
> Upload \"writes the program to the Arduino Nano.
Upon completion, the display on the field welder should show a low battery warning for the USB port voltage, as the default low battery warning is set to 11 V.
Now that you have completed the construction of the spot welder, this is how to use it.
Basic information: security instructions :(V3)
Use this product only if you have some basic knowledge of electricity.
The water flow here is very large and dangerous.
For safe operation, the on-site welder is able to provide welding current up to 1000a.
Do not use car batteries that can provide more amps.
For example, the 40Ah Astra car battery can weld 0 well. 1mm to 0.
There are 25mm nickel bars on the battery.
If you want to use a higher current or a longer welding cable, you can take the risk yourself.
The absolute maximum rating is about 1400A welding current.
Do not connect it to the car battery by mistake. The U-
The aluminum part is negative to the battery (black)pole.
Set the welding time to 2 or 3 MS on the first use to see how it is welded.
Then increase the time until you get a good weld.
If the time is high,g.
For very thin nickel, your nickel material will \"explode\" at 20 MS \".
Optional: for maximum safety, do this before the first use: Open the welder and measure the resistance between the two aluminum components with a multimeter.
It should show arround Ohm.
If it shows 0 ohms, a short circuit is displayed or a defect occurs.
If you don\'t have a multimeter, you can do this: turn on SpotWelder, turn off the auto-identification function, then put a nickel bar on a piece of wood, and put a welding tip on the nickel.
Then quickly touch the nickel with another welding tip.
You\'re fine if nothing happens.
If you burn a hole in the nickel bar, it\'s wrong.
Quick start: new menu and OLED display function: Pulse time displayed on the home screen (
Adjust by turning the therotary encoder)
, Whether the battery voltage, the completed total weld and the automatic identification function are activated.
You can go to the menu by rotating the encoder \"click\"/\"press.
In the new V3 or v2.
2 with the \"auto exposure\" feature integrated, you can upgrade the \"old\" spot welder using the new feature prettyeasy.
You only need a few parts :(
SMD 1206 or wired parts according to your preference)
Connect them according to the schematic diagram. (
The probe is the middle pin of the mosfet)
Then upload the new v2.
2 Arduino codes for Arduino Nano.
When the AutoPulse function is activated, you cannot activate the pulse using a normal foot switch.
Therefore, it is recommended to use the connector to disassemble the cable connected to the arduino pin D3.
If you do this, you need to install a 20 k resistor from pin D3 to GND to make sure the Arduino reads a stable GND signal if the connector is removed.
Alternatively, you can start the Arduino with v2.
Disable the SpotWelder software of the spoulse feature again.
Using this method, there is no need for a 20 k resistor or a connector to make the cable operational.
Description video :(
20 k resitor from Pin D3 to GND is missing in the video, sorry)
Arduino spot welder needs automatic function on new V3, because with the help of this very simple plug-in, the default is already included, you can power the spot welder directly from the car battery instead of the 12 v power supply.
The only component that needs to be added is the 25 v 470f capacitor.
This is enough to keep the voltage of the Arduino board when the pulse occurs and the car battery voltage drops.
It works around 50 mS.
For longer pulse times, it is still recommended to use a separate power supply.
I added the capacitor between the Arduinos Vin pin and the GND.
Pay attention to the polarity of the electrolytic capacitor! “-
Go to GNDand to Vin.
You can then connect the cable input from the PCB voltage to the car battery positioning terminal to start the spot welding machine.
The GND input is not needed as it has been connected to the car battery via an aluminum sheet.
The oscilloscope measures to check if the mod is working :(
Reference picture)
Arduino will continue to run even if there is no extra capacitor, but I will not recommend it.
The 22 v voltage spike is very short and there is no problem with Arduino Nano and other components.
As you can see in the picture, there is no significant voltage drop in this short pulse time.
Here you can see that the voltage goes down as the 45 MS pulse goes down to about 8 v.
This is still enough for Arduino to work properly, so the pulse time of about 50 ms is the maximum time that the module can use. All the components used for this sopt welder are through the hole assembly.
So it\'s easy to weld.
Starting from the small part, all the way to the larger part.
The welding head is made of solid copper wire 10 mm² thick.
The cable is a flexible copper wire of 16 mm².
Do not make the welding cable long (max. 50-60cm each).
Very long cables can cause high induction voltage spikes, which can damage the welder. (update 08. 2016)-
In the new version, you must connect the JP1 on the Arduino board to the JP1 on the Mosfet board, and the JP2 on the Arduino board to the JP2 on the Mosfet board.
Use pin heads and sockets.
These jumpers connect the ground of the two boards.
You can see the effect of the green pcb in the new picture. (update 12. 2016)-
A new series of pictures filled with the pcb was added, which should make it easier to understand.
New v3 diodes used do not require protection diodes: Schottky:-
100BGQ015 cottage. com Part: 844-
TV: 5KP13A-100BGQ015E3/54 Mouser. com Part: 625-5KP13A-
Why add diodes?
When using very high welding current or long welding cable, the diode can be used to make the spot welding machine more reliable.
They reduce the peak voltage that occurs due to the inductance of the welding wire.
This is necessary as high voltage spikes can damage or kill your mosfet.
A very detailed explanation can be found here, including adding diodes: you can make some beautiful wires with the diode\'s cable lugs to make it look beautiful, or weld directly to the welder.
The function is the same.
Just make sure that only the high power soldering iron is welded on the schottky so that the diode does not heat up when welding.
The cable of the diode should be 10 mm² (7 or 8 awg).
For TV diodes, you can also use thinner cables if it\'s just a short cable.
The short conclusion: I did some measurements with my $20 oscilloscope, which is not very accurate, but you can see the effect of the diode.
The first measurement was done on a normal spot welder without additional diodes installed.
As you can see at the end of the first pulse, there is a voltage spike up to about 34 V.
This is no problem because the rated voltage of the mosfet is 55 V max.
But if you use a longer welding cable or a very sturdy car battery capable of providing a very high current, the voltage may exceed 55 V.
This can then damage or damage the mosfet.
To eliminate voltage spikes, you can install diodes on the welder.
You need a TV and a Schottky diode.
I only installed shottky when I first measured it.
This leads to strange oscillation behavior and even affects arduino, so the program crashes.
You can see this in the picture of the oscillation voltage.
Finally, I measured it with two diodes (
TV and Shoreditch Tube)installed.
Now the voltage spike at the end of the pulse is only about 20 v.
Even if there is a higher current or a longer welding cable, the voltage will not be much higher because the diode will prevent this from happening.
What car battery can I use for spot welding machine?
It is recommended 12 V 40Ah car battery, but everything that can provide 400A to 600A should be good.
I do not recommend using the so-called \"deep cycle\" battery.
They look like car batteries, but these do not provide a high current for a short period of time.
They can provide a small current of 20 to 50 a in a few hours.
They can provide high welding current but may be damaged after some welding.
What nickel bars can I weld?
You should use 0. 1mm to 0.
25mm nickel bars. Typically 0.
The 15mm Nickel Belt is suitable for all standard applications. 0.
If the thepulse time of 3mm nickel-plated steel strip increases to about 6-10 MS (
This time set up with 440 a orCCA car battery).
If you want to use 0, you can also try using a slotted nickel strip.
3mm, because the slotted gives you better welding points in the case of small current or short pulse time.
What pedal switch can I use?
You can use any switch that you don\'t have (normally open).
The foot switch does not have any current, so even a very small switch can work. (
Example of foot switch.
Do not wrap the foot switch wire around the welded cable and try the manual switch.
This may damage the spot welding machine because of the induced voltage.
How long should the welding cable take?
Make the cable as short as possible.
Recommended 16 mm² (5awg)0.
5 m per cable.
If you make the cable longer, the welding pulse will weaken unless you use a thicker cable.
In addition, due to the high induction voltage generated in the long cable, you are more likely to damage the spot welding machine with a long cable.
What power supply does Arduino board need?
The new V3 does not require a separate power supply for welding time below 50 MS
It can be connected directly to a car battery or a fat absorbing pole.
The 12 V 2A or 1A power supply works fine for the old V2.
Alternatively, the 3 s Lipo/Liion battery can also work perfectly.
Can I power the arduino board with a car battery?
Yes, in the new V3 you can power it directly with a car battery or Lipo and the soldering time is less than 50 MS
For V2 or older in a standard configuration, you need a separate power supply or battery.
But if you add a 470 f 25 v capacitor between Arduinos Vin and GND, you can power V2 and the old ArduinoBoard from the car battery.
Is it possible to use a PC power supply instead of a car battery?
No, you need a car battery.
The Pc power supply cannot give you enough current welding.
You need about 400A.
The Typicall power supply can provide up to 50A.
In addition, the power supply usually does not like short circuit, which is the job of the welder.
When I plug into Arduino with USB, my computer can\'t find it!
If your system does not automatically install the necessary drivers that you need to install manually.