welding 18650 cells with DN-5 spot welder

[madin88]

willow, did you use pure nickel or some kind of nickel plated steel?
if you go below setting 1, than the welder does nothing what means time cannot be decreased (at least thats what the DN-5 does).

Well makita and hilti uses plated copper in powertool packs. There must be reason for that too? I have to check bosch, hitachi and dewalt. Also those plated copper strips were easier to spotweld than purenickel (with dn-10). I just dont know why?

are you 100% sure its tinned copper makita uses and not some kind of nickel-copper alloy below the surface). visually i think you will hardly see this..

what about mechanical strength of nickel vs copper? what happens if you pull if off?
what happens to the weld under vibrations?

many many things to think of and not only electrically conductivity..

 

[Willow]

http://www.yoybuy.com/en/show/35788308198/

You can select model in the drop down menu.

They have a strange arrangement where they get you to make 2 payments, one to purchase the goods then another for them to release it from the warehouse...

their PAYPAL was not working - so had to do cred card....

I'm going to try a few things with the welder - like cranking it up and weld some tin cans together... just to try it out for other applications. Though it is advertised as an 18650 battery spot welder, I'm not sure it was designed as a dedicated tool to do the job - rather 'marketing hype'.... and it just happens to be able to weld tabs to batteries.

test pieces were trimmed from batteries that had already been welded - so most likely pure nickel strip.

 

[ridethelightning]

i think with slightly thicker strip, the slight varyations between welds may not be so noticable, and it might be more forgiving at slightly higher settings.
with the 0.12 mm, its just luck weather you blow a huge hole in it or not.

very interested to hear about plated copper being easy to weld. that would be like 10 times better cause the conductivity of the nickle is ratshit anyway(4 times worse than copper).

copper does work-harden though so there may indeed be issues with vibrations on the welds...

would love to hear what andreym has to say about this at this point as he has an identicle unit i believe and makes some really nice packs with it.

 

[anttipaa]

No im not sure is it tinned or nickel plated. Im starting to think it might be nickel plated? When I pull those strips welds stays on cells. You need to use some force also. So I think thats good thing. Dewalt uses thick strips (I think its pure nickel) and when you rip those off it leaves holes to cells..

Its just hard to find plated copper strips and I was hoping someone would know where to get them.

 

[madin88]

these are the nickel-copper alloy strips im going to try out: http://www.amazon.de/Lötfahnen-Schw..._sbs_ce_1?ie=UTF8&refRID=1GR9CP7A9CN6Y9ZKRGQ9
they are available in other thickness sizes and length etc.
conductivity will be about 20% better what i have found out about nickel-copper alloy (need to ask the supplier how many percent copper and nickel it has, than check again), but first lets see if they can be welded good with the DN-5

 

[kdog]

Hey does anyone know the output voltage of these spot welders? Im trying to make one ( think YouTube) and whilst total power is not a problem (easy to melt stuff) delivering it is a bit trickier... My results are sort of similar to willows vid in that I can blow holes and ( more promisingly) do weak tacks that don't hold well. Currently testing at about 3.5v but i might try down to 1v and up around 10 v (sacrifice some amps)- need to achieve hotter and shorter heat delivery.
It's fun if anything, and only cost me two bucks so far (tip shop specials)
Kdog

 

[Willow]

in the hood KDOG.... should catch up.

 

[Nobuo]

Hey does anyone know the output voltage of these spot welders? Im trying to make one ( think YouTube) and whilst total power is not a problem (easy to melt stuff) delivering it is a bit trickier... My results are sort of similar to willows vid in that I can blow holes and ( more promisingly) do weak tacks that don't hold well. Currently testing at about 3.5v but i might try down to 1v and up around 10 v (sacrifice some amps)- need to achieve hotter and shorter heat delivery.
It's fun if anything, and only cost me two bucks so far (tip shop specials)
Kdog

3.3V, 3.5V is what I find the common on the spot welders. Higher voltages could reduce the ability to make close spots because the poles would short.

 

[litespeed]

I think that is the lure to capacitor discharge welders is the ability to adjust the voltage for a quicker weld with less heat left behind. The higher the voltage the quicker the weld time. The trick to the transformer/low voltage welders is a proper audrino to achieve a dual pulse perfectly timed to minimize heat but still get the job done. Fritz's dual pulse capacitor welder I am building is supposed to be up to 10,000 amps and voltage adjustable from 0v to 23.5v. I'm building the 800watt second one and it appears it's going to cost me right under $600 to build. I'm about 85% done. This is what I understood when deciding what I wanted to build.

Tom

 

[riba2233]

I hope that that one isn't intended for 18650 cells. There is a lot cheaper option for that, almost 10 times cheaper.

 

[litespeed]

Actually it is for 18650 cells and what ever else I want to use it for. I never wanted the cheapest way, I wanted the best for a budget. I tried a cheap welder and it was a waste of time.

We will see if I regret it in the end but I feel pretty good about it right now.

Tom

 

[ohzee]

Sounds like you have the right mindset Tom.

I have been kicking these things around in my head lately. Like to do my own welding , but don't wanna pay and pray.

 

[riba2233]

I will be offering affordable solution for welding 18650 cells soon.

 

[ohzee]

I will be offering affordable solution for welding 18650 cells soon.

Great because I am in the market :0)

Look forward to your product. I have around 250 cells in route to me now and I cant use em all in flashlights.

 

[riba2233]

Thanks and lol for flashlights :lol:

I'm trying to get it done as fast as I can

 

[kdog]

Thanks nobuo for the voltages. With respect to the higher voltages and poles shorting, do you mean arcing between the close electrodes in air or something more complex like across the surface of the work piece.

Hey willow, I'd be keen to catch up, I'll PM you with my details.
K

 

[Nobuo]

Thanks nobuo for the voltages. With respect to the higher voltages and poles shorting, do you mean arcing between the close electrodes in air or something more complex like across the surface of the work piece.

Hey willow, I'd be keen to catch up, I'll PM you with my details.
K

Spot welding is about high current and low volts.

More current is better than more voltage. You may need more voltage is if you have a high resistance metal.

The idea is a pair of pulses of high amperage through two pieces of metal, which will heat up and melt a pair of spots, sticking them together.

electrical resistance = heat. We need low resistance metals on the poles (copper/Silver) so we could create heat in a higher resistance metal (Nickel/Steel).

This process is based on the principle of OHMS LAW where V(voltage) = I(current) x R(resistance) or I(current) = V(voltage) \ R(resistance). Most Metals have very low Resistance (micro-ohms). Low voltage outputs together with the Low Resistance can produce a very high current through the metals to be joined.

It almost instantly melts the metal where the electrodes make contact.

Higher Voltages could make an arcing through air, for the 2mm to 5mm of the spots needed for welding on the 18650 cathode and anode the Voltage shouldn't be more than 5V, there is also no need for that.

 

[chucho]

I will be offering affordable solution for welding 18650 cells soon.

Great because I am in the market :0)

Look forward to your product. I have around 250 cells in route to me now and I cant use em all in flashlights.

+1

What is the real diference between DN spot welder and the spot welders they use in car work shop like this one?

Could i modify one of these for welding 18650 cells?

 

[litespeed]

You need a timer system. You have to set up a set time through trial and error or educated guess. If you use a switch or even a foot switch you would be constantly sticking the probs to the work, blowing holes in what ever your welding and probably poor welds from to too short of cycle time.

Tom

 

[cj7hawk]

Please excuse what is probably an ignorant question, but why choose that kind of welder over one purpose built for 18650 cells?

eg;

The only thing I could think of was the shape of the cell packs, but even that didn't make sense...

Sorry if it's a stupid question, but I'm new to this and purpose built ones cost around $150 ro $250 shipped - I realize there's probably a really obvious reason why, but I haven't been on this forum for long.

Regards
David

 

[silentflight]

Please excuse what is probably an ignorant question, but why choose that kind of welder over one purpose built for 18650 cells?

I'm not certain what the limitations of the 788+ model in the photo you posted are. Perhaps it cannot weld the same thickness of nickel strips. A member from Europe bought the 787+ model and posted a generally favorable review of it.

I would like to buy the 788+ model in the next few weeks and wonder if anyone has purchased the 110 volt version. Some of the ads on alibaba and ebay say 110 volt in the title, but 220 volt in the small print. I'm concerned that the seller may have just replaced the cord. One dealer I messaged on alibaba said he was getting feedback that some 110 volt units sold to the US were not working properly. He suggested installing a 40 amp circuit breaker. This sounded risky at best and has put me off buying a spot welder for the moment. I may just buy the 220 volt version and install a 220 volt circuit in my house to accommodate it, but would rather not. I'm all ears if someone has advice/thoughts/experience with the 788+ on 110 volts.

 

[kdog]

i could only find limited reviews (1 on youtube) on these welders.. i was thinking of splashing out for a while but the one review i read was initially good then his enthusiasm dwindled but he never said why
anyone else got some info on them, how do they compare to the DN-5
k

 

[Nobuo]

i could only find limited reviews (1 on youtube) on these welders.. i was thinking of splashing out for a while but the one review i read was initially good then his enthusiasm dwindled but he never said why
anyone else got some info on them, how do they compare to the DN-5
k

That welders are on another division. DN-5 is the right machine. The other ones posted in this thread are a low-cost option. All that chinese ones below $300 are more or less the same inside. take the cheapest one if you don't want to spend ~$500

 

[kdog]

Well I achieved some welds with my microwave transformer spot welder. I wound secondary coil to 1.7v but it was to slow to deliver heat- so I rewound to 4.7v and it is much more lively. I welded a piece of nichrome wire to some sheet steel. mostly im having trouble getting the test bits to actually stick together, It seems to get the heat to weld, to much heat goes through the work piece ( battery would be frazzled ). I still have a couple more parameters to change and testing to do. i think smaller electrode tip diameter, closer spots and lower V/more A might do it

OTOH I have stumbled across spot soldering...and I'm getting some good results. A tinned tab hit with the spot welder solders instantly to the work piece with almost negligible heat imparted to the can. its a good bond with a big surface area.
It's all learning..
k

 

[ridethelightning]

i went to the tip shop the other day and picked up a couple of large microwaves on my cargobike.
i had similar results :lol:

we should go for a group ride sometime kdog, just round the corner from willow here...