Author Topic: kWeld - "Next level" DIY battery spot welder  (Read 142900 times)

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Offline FredNuno

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #650 on: January 11, 2019, 08:18:20 pm »
Hi Frank, thank you for your response.
I have tried everything you posted, but no avail, until now. But I'm over this matter and I will solve this problem, I'm sure. From the begin I have choosen 3,3 V. I have read the manual.
FredNuno.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #651 on: January 12, 2019, 11:03:46 am »
Here's again a new firmware, this one allows to alter the minimum current threshold through the menu. I realized that this would be important for users with weaker batteries who like to keep their system as it is. They wouldn't be able to use the welder anymore otherwise. And I had also the request to raise the threshold. If your battery delivers 1400A, then setting the minimum to e.g. 1200 might further improve the arcing detection sensitivity.
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Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #652 on: January 12, 2019, 11:17:08 am »
p.s. new kWeld electronics just arrived and can be ordered through the shop  8)
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Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #653 on: January 17, 2019, 12:17:16 pm »
I've been firefighting during the last days, after an increasing number of kWeld users reported me that the rotary encoder on the board had become unreliable. It turns out that it is a huge quality problem with the component itself. There are tiny plastic elements inside that break loose and end up blocking the contacts. The kWeld production test couldn't catch this, because this only happens after using the part for a while. It's even more annoying because I deliberately use quality brand components only for the entire design, in this case a Bourns PEC12R-4220F-S0024.

We are busy replacing the rotary encoders on the entire current production batch with this new component: EN11-HSB1AF15 (Digikey 987-1186-ND). I have disassembled one of these, their internal construction is way better. The only drawback is that they count in opposite direction, which is why I had to update the firmware again. This version has a new menu item "Encoder" that allows you to select "normal" and "reverse" counting direction.

If any of you guys are having problems with your welder, then please let me know. I'll do what I can to resolve this issue for you.
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Online EV

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #654 on: January 27, 2019, 09:33:32 am »
I updated the FW to r2.8. No problems!

I also tried to weld with 0.0J energy! It is not 0.0J! It was very big, the electrodes got very hot and burned hole to nickel strip! When setting to 0.1J the energy level is correct.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #655 on: January 28, 2019, 09:34:20 am »
I updated the FW to r2.8. No problems!

I also tried to weld with 0.0J energy! It is not 0.0J! It was very big, the electrodes got very hot and burned hole to nickel strip! When setting to 0.1J the energy level is correct.
You've actually found a bug that I have introduced in the latest firmwares. I was using E=0 to encode the "OPEN" calibration step (in need to disable the undercurrent test) and forgot about the consequenses. Just fixed this, new firmware attached to this post.
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Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #656 on: January 28, 2019, 09:39:43 am »
"Encodergate" is finally over. I switched production to a new type (after having disassembled one to see the internal construction): EN11-HSB1AF15. We have also replaced these parts in the entire existing stock.
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Offline bobmutch

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Re: low cost DIY battery spot welder [guesses on ... - solved]
« Reply #657 on: February 17, 2019, 07:55:42 am »

EDIT2: Okay, I'll have to take back everything that I said about using flux. The below welds are with 0.2mm nickel strips, and you can see the coloring which cannot be prevented when doing it as usual. Except both leftmost welds per cell, where I added a drop of flux! Awesome, I can definitely recommend that to everyone! The used flux was Chipquik SMD291.



Hi Frank, I posted your test on a FB group and some people think it may be that the better looking welds are because they are further apart (both far left welds on each cell are electrodes appear to be further apart). Do you have a picture showing this results where the electrodes are not further appear on the no-discoloured welds when you put the flux on top of the Nickel between the Nickel and the electrodes?


Thanks Bob.
« Last Edit: February 17, 2019, 08:12:24 am by bobmutch »
 

Offline tatus1969

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Re: low cost DIY battery spot welder [guesses on ... - solved]
« Reply #658 on: February 20, 2019, 09:09:36 am »
Hi Frank, I posted your test on a FB group and some people think it may be that the better looking welds are because they are further apart (both far left welds on each cell are electrodes appear to be further apart). Do you have a picture showing this results where the electrodes are not further appear on the no-discoloured welds when you put the flux on top of the Nickel between the Nickel and the electrodes?
Sorry, I wanted to repeat this but ... too busy... I see what you mean though, but I can reassure you that the results with and without flux were very different. It's not the larger distance that makes the spots shiny.
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Offline lothar77

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #659 on: April 06, 2019, 01:34:13 am »
Can someone point me to page 2 of the rev3 schematic? I have pg1 of rev3 from post 449 but nothing since. A parts list would do too. I have pg2 of rev1 but it's not matching up with my new-ish rev3.

I was moving right along on my second pack when I had to adjust my p/s battery. On the next weld sparks and smoke ... it seems one jaw of my small bent-nose pliers snuck through the hole in the case on the output side. D8 now shorts the output. I noticed that D19 has the same marking and I'm thinking D8 is the LF SMDJ28A (two on order). Also, it looks like D18 was populated - a part number for that would be appreciated too.

Many thanks T. for a great device. I appreciate all of the thought and care given to the project. Truly impressive
« Last Edit: April 06, 2019, 08:05:47 pm by lothar77 »
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #660 on: April 06, 2019, 06:41:28 pm »
Can someone point me to page 2 of the rev3 schematic? I have pg1 of rev3 from post 449 but nothing since. A parts list would do too. I have pg2 of rev1 but it's not matching up with my new-ish rev3.
That component blows when a quite common mistake happens, and that is feeding voltage into the electrodes from your battery under construction. In most cases, this only causes this component to turn into a short, which protects the rest of the circuit from this voltage.

That diode (it is actually D18, this is a misleading print) is in fact a SMDJ28A, but to improve protection you can also solder an SLD8S28A (= D8) to the bigger pads instead. That one can take more power (but will still eventually fail if that accident takes too long).
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Offline lothar77

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #661 on: April 06, 2019, 08:34:22 pm »
Thanks so much for the speedy reply and confirmation of the components. I'm eager to get the kWeld unit back into action!
 

Offline lothar77

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #662 on: April 10, 2019, 01:09:18 am »
A quick update ... I got the parts yesterday, finished the kWeld board repair, finished the last weld on a new 26650 LFP pack (the one where things went south), and repaired an 18V NiCd tool pack. Many thanks for the support and a unique product that I enjoy using.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #663 on: April 10, 2019, 07:11:00 am »
A quick update ... I got the parts yesterday, finished the kWeld board repair, finished the last weld on a new 26650 LFP pack (the one where things went south), and repaired an 18V NiCd tool pack. Many thanks for the support and a unique product that I enjoy using.
Happy to hear that your unit survived!
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Offline Fraser

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #664 on: April 24, 2019, 04:44:53 pm »
Hi Frank,

I bought one of your first generation kits with the potentiometer control  :)

Sadly ill health got in the way of putting it all together  :(

I am revisiting the world of battery tab welding and see that the KWeld has been developing nicely  :-+ I have taken a look at what fully built tab welders are coming out of China these days and they look as bad as ever. The KWeld is so much more refined  :-+

I think I will just buy the complete set of parts with the latest board revision and make life easy for myself this time. The MK1 PCB is languishing in a box with all the bits and pieces needed to construct probes etc.

You can expect an order from me very soon  :-+

Best Wishes

Fraser
« Last Edit: April 24, 2019, 04:46:46 pm by Fraser »
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #665 on: April 25, 2019, 09:29:42 am »
Sadly ill health got in the way of putting it all together  :(
I hope you are doing well again?

You should only need the new electronics module and the cable assembly, you can order them separately from the shop. Plus maybe the busbars, I don't remember anymore if they were different in rev1 (I don't think so). Can you maybe post a picture?
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Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #666 on: May 10, 2019, 04:58:25 pm »
I finally made it! "kSupply" power supply module 0-12V 0-70A to charge the ultracapacitor modules are ordered and available in my shop for preorder. https://www.keenlab.de/index.php/product/ksupply/  8)
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Offline Will_SG

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #667 on: May 20, 2019, 03:32:27 pm »
I finally made it! "kSupply" power supply module 0-12V 0-70A to charge the ultracapacitor modules are ordered and available in my shop for preorder. https://www.keenlab.de/index.php/product/ksupply/  8)

Ordered!

Understand that you had recommended the DPS-800GB to be used with kSupply. I am assuming that DPS-1200FB (12v 100A) will work as well. If it doesn't, what are the criteria for selecting the power supply? thx!
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #668 on: May 21, 2019, 09:08:24 am »
Ordered!
Thanks!

Understand that you had recommended the DPS-800GB to be used with kSupply. I am assuming that DPS-1200FB (12v 100A) will work as well. If it doesn't, what are the criteria for selecting the power supply? thx!
You can use the mounting holes to connect any kind of 12V power source, but the card edge connector on the module will only fit to certain PSU models. I've started a list of suitable models, so far these are on that:
Fujitsu DPS-800 GB
HP HSTNS-PD05 (connector layout identical to DPS-800 GB, but yet to be confirmed)
HP HSTNS-PR01

Here are pictures from the two different card edge layouts that I am aware of, and that are supported:
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Offline Will_SG

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #669 on: May 21, 2019, 05:09:13 pm »
guess I have to try my luck for the 1200FB. Although the pins layout are similar but the width are different.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #670 on: May 23, 2019, 11:15:24 am »
guess I have to try my luck for the 1200FB. Although the pins layout are similar but the width are different.
Yes, the connector won't fit, but you still can solder the wires directly to the PSU and follow the info online how to enable it.
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Offline mzzj

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #671 on: September 03, 2019, 12:55:26 pm »
Took less energy than I expected to weld 0.10 and 0.13mm tabs and I was able to get sound welds with only 0.132F total capacitance.
0.10mm tabs were welding best at about 21 volts =  29 Joules
0.13mm tabs were ok at 25 volts = 40 Joules.

Weld pulse is pretty damn short and if the contact pressure is not sufficient I get loud bang and blackened terminals.
Need to re-write the program to actually use dual-pulse functionality, now the pre-pulse is already doing all the welding and draining the caps.
Took only a bit over a year to cobble up the 0.7F 35v cap bank.

Welds the 0.13mm tabs fine at 11 volts =40 joules

Same energy input but without the loud bang the 25v charge voltage previously was making  :-DD
Still throws shover of sparks if the contact is bad but without loud bangs.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #672 on: October 08, 2019, 02:23:54 pm »
Just wanted to share a piece of work with you that I am doing for a customer. These teflon handle will provide additional heat insulation and should allow significantly faster welding speed. The assembly also uses 6AWG leads, which should help keeping them cooler as well.

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Offline dirtcooker

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #673 on: October 18, 2019, 05:42:20 am »
I'm using, an HP DPS-1200FB with kweld, kcap, and ksupply. I can confirm that it works well, no problems unplugging it with ksupply and kcap attached. This power supply seems to be bullet proof. However, I had to make the following modifications to ksupply: remove R23, solder a 12k resistor between pins 36 and 37 (to turn the power supply on), and remove the connection of pins 13 and 52 to the circuit board. +12v ouput fills positions 1-13 and the corresponding positions on the opposite side, and pins 14-26 are ground (see photo). Thus, the unmodified ksupply when attached places a short circuit directly across the power supply output. Fortunately, the supply is well protected against such things, refusing to power up at all with an unmodified ksupply connected.
I dug up some information about this power supply on the internet, which I summarize here:

DPS-1200FB Power Supply
http://colintd.blogspot.com/2016/10/hacking-hp-common-slot-power-supplies.html
Pinout:
1-13: +12V Power out
14-26: GND Power out
27, 28, 29: I2C slave address selection pins.
30: signal GND (for I2C and I2C slave address selection, I guess)
31: I2C SCL
32: I2C SDA
33: ENABLE#
34: LOAD SHARE
35: STATUS
36: PRESENT
37: +12V stand-by, good for 2.5A
38: PSALARM, normally have an active low alarm output
I can confirm that pin 37 is +12v when the power supply is plugged in, and connecting pin 37 to 36 and grounding pin 33 turn the supply on. I have not used the other pins.
I found on ebay a circuit board for sale with edge connector for these supplies, which list the models that it works with (listed below). DPS-800GB is one of them, which is mentioned in the manual that ksupply will work with. Since these power supplies obviously have different pinouts, I am curious to see how they solved the compatibility problem so I ordered one. When I receive it I'll post again.

Common Slot" Power Supply Models:
DPS-800GB A
DPS-1200FB A
DPS-1200QB A
PS-2751-5Q
PS-2751-LF-1F
HSTSN-PL12
DPS-700LB D
PS-2112-5L
DPS-750RB A
https://www.ebay.com/itm/DPS-1200FB-Power-Supply-Adapter-Board-10-Pcs-6-2P-Cables-For-Ethereum-Mining/292358226805


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When all is said and done, much more is said than done
 
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