DIY Arduino Battery Spot Welder et 48 v?

Batteries, Chargers, and Battery Management Systems.
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DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 07 2020 8:55pm

HI
i do not have any battery car.
i do have a 48v 13s2p vtc4 cell.

i want to spot weld need battery using nickel stips.

what can i use?

can i use DIY Arduino Battery Spot Welder? is it compatible the last version

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by obcd » Apr 08 2020 7:23am

A good spotwelder should furfill 3 parameters:

Controllable current.
Controllable pulse time.
Controllable pressure of electrodes.

The first 2 can be achieved with electronics. The third is another thing.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 08 2020 4:20pm

HI obcd ,

i understant that you beleive those are important point. unfortunately it does not help me .

concretely what device could i use ?(not to expensive...

i also have couple vtc4 cell available. does ardurino malectronic can work with 3s1p?


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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 12 2020 5:38pm

yeah i did this search but didnt lead to success hence i am here

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serious_sam   10 kW

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by serious_sam » Apr 12 2020 6:30pm

want to build wrote:
Apr 07 2020 8:55pm
i do have a 48v 13s2p vtc4 cell.
IMO that pack isn't able to produce enough power to perform (satisfactory) welds.

And 48V is too high for spot welding. You really want something around 12V, give or take. Higher voltages are more likely to produce arcs and sparks.

As an example, my diy car battery powered welder is using a 750CCA battery (Arduino controlled with 16x low Rds mosfets), which probably puts out 1000A+ in short pulses (I have no way of actually measuring the current, but it gives you a ballpark). It produces satisfactory welds, but would be better with more battery.

You can weld with lower currents, but then you have to extend the weld duration, and you end up with poorer welds and hotter batteries.

If you configured your VTC4 pack into 4S6P, you could get nominal ~14.8V pack. VTC4 cell at 30A has about 0.7V sag. viewtopic.php?t=96162 So your 4S6P at (only) 180A has 2.8V sag, giving you 14.8-2.8=12V nominal.

So that sag is at only 180A. Highly doubtful that you can get anywhere near 1000A to produce a good weld. Like I said, not enough power from the pack you have.

So IMO you really need a better power source to start with.

And finally, if you can't learn anything from all the great threads here on ES, such as the ones John linked to, then I honestly think that you're biting off more than you can chew.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 12 2020 7:10pm

want to build wrote:yeah i did this search but didnt lead to success hence i am here
wut?

in answer to

> what device should i use

my understanding is there really are not too many choices

the DIY projects being far superior to the commercial products

at reasonable pricing anyway.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 12 2020 7:11pm

You cannot choose the welder to match your power input.

Only the other way around.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 12 2020 7:53pm

ok , if i find a battery is there a list of battery specs , company , trademark , size amps that will work ?

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by serious_sam » Apr 12 2020 9:22pm

All that info is in the threads. Read them yourself. I suggest the kweld and JP threads.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 12 2020 9:37pm

serious_sam wrote:
Apr 12 2020 9:22pm
All that info is in the threads. Read them yourself. I suggest the kweld and JP threads.
hi what don t you like about arduino's?

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 13 2020 3:12pm

We would love whatever the platform, if the end result came close in actual performance

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 13 2020 10:13pm

i understand than you are not satisfied with the performances .
do you know what they can be attributed to?

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 13 2020 11:02pm

Not sure what you mean.

Just parse through the appropriately relevant threads and start asking questions there.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 14 2020 12:23am

yeah i read a lot of them . a lot of people say use arduino .
my question was what do you think is the probleme of arduino that made it so for you that it did not perform well.
or maybe what do you think the 2 other have that arduino does not have?

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by serious_sam » Apr 14 2020 6:50am

want to build wrote:
Apr 12 2020 9:37pm
hi what don t you like about arduino's?
We didn't say that. My welder uses an Arduino. It's a good basic welder. Arduino is a good choice, and easy to use.

My welder works well. It's a bit rough looking, but I made it mostly with parts I had in my garage. It's a means to an end. I needed to make a battery pack. So I made a tool that can do the job. Nothing fancy. No frills. Minimal development time. Tough enough to do the job. Do the job, pack the tool away. More time for riding!

I used 4x 8AWG cables in parallel, kept them as short as physically possible, and used 16x very low Rds mosfets. So the welder has the lowest practical inductance and resistance, and is capable of handling very high currents without burning up. But I just don't have the batteries available to push those high currents (another car battery in parallel would be good). IMO I had to set the pulse duration a little bit too long to get enough energy into the weld. I think I could produce slightly better welds more consistently with higher current and shorter pulse duration. But that has nothing to do with the Arduino. It's the battery. That's why I said I think your VTC4 battery is too small.

If you plan on making your own welder, you should read those threads previously mentioned. They're long and a bit boring, but there's some great information in there that's worth the read. Sorry that English isn't your first language, so it makes it harder for you to find the important parts. But I only know one language, so you're already smarter and more persistent than I am.
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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 14 2020 7:29am

DIy you build it your self?

it does not look like v3.3 https://malectrics.eu/product/diy-ardui ... lt-kit-v3/.

your loosing me with that I used 4x 8AWG cables in parallel, kept them as short as physically possible, and used 16x very low Rds mosfets. hahaha i guess you build one whit those parts and used mlectric electronic parts right

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by serious_sam » Apr 14 2020 5:28pm

See the cables: more and bigger cables is better. I used 4x 8AWG in parallel. It's what I had at home so I used it. Anyway, thick cable is better for low resistance. Multiple cables is better for low inductance and slightly more flexible than single thick cable. Cable is cheap. Use lots.
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See the mosfets: there's no kill like overkill. I used IRFB7430PBF because they are the lowest Rds I could find at the time in TO220 package with 40V rating. They have a high avalanche energy and high pulse drain current rating. I used a MIC4452 12A driver to drive all the mosfets through individual gate resistors (~18 ohm each IIRC).
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It's very simple stuff. I just went overkill because I only wanted to do it once, use it, and move on. This is not mass production. It's designed like it is because the aluminium and copper I already had at home, so that dictated the layout to some extent. I only had to buy the mosfets, drive ic, diodes, and the battery terminal clamps. I didn't want to waste time with designing and getting PCBs made. Perf board is fine for the job. I don't care what it looks like. Actually I like how it looks anyway. I like cap screws, aluminium, and copper. Maybe an enclosure would be nice, but I've already packed it away on a shelf.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 16 2020 6:29am

I'm not saying anything against Arduino.

For me, rather than DIY re-inventing the wheel, just read through the threads starting at the top of the list I sent you

and the best one, all ready to go, will be obvious, just order it put it together

and buy the recommended battery to power it

and you are done, easy peasy.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 16 2020 9:47pm

serious_sam wrote:
Apr 12 2020 9:22pm
All that info is in the threads. Read them yourself. I suggest the kweld and JP threads.
hi john 61 my questions what dont you like of the arduino was adressed to the participant that wrote the above.

I read you last comment you feel that '' the best one, all ready to go, will be obvious,' which one do you find obvious? cause when i read them I saw 2 most recommended Kweld more expensive and malectronic but the this is that i dont get what peolple that prefer kweld have to reproch to the cheaper Arduino...
do you understand?

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 17 2020 5:00am

This is not something to skimp on price.

The commercially sold products are crap.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by serious_sam » Apr 17 2020 6:14am

want to build wrote:
Apr 16 2020 9:47pm
You should be clearer with what you are trying to do. Which one of the following options is your plan:
1. Do you want to design and build your own welder (DIY)?
2. Do you want to buy a kit that you need to assemble?
3. Do you want to buy a welder that is ready to use?

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 17 2020 3:30pm

Or

4. DIY but assemble / build only, from a proven, tightly spec'd design.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by want to build » Apr 18 2020 11:23pm

Hi
my goal is to spot build correctly and i dont have money do buy elaborate stuff.

i can do to save a bit of money i can buy a kit that you need to assemble yes
but not to design and build your own

i figure that is more precise in deed.

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Re: DIY Arduino Battery Spot Welder et 48 v?

Post by john61ct » Apr 18 2020 11:44pm

So, OP, genuine question here.

Why have you not ordered this yet?

https://www.keenlab.de/index.php/portfolio-item/kweld/

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