Search found 289 matches

by tatus1969
Oct 15 2019 4:38am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: New welding metal

ElectricGod wrote:
Oct 14 2019 9:37pm
check out that .1mm thick alloy! Not much more resistance despite being 1/3rd as thick.
That's awesome! Curious to see how that welds.
by tatus1969
Oct 11 2019 3:58am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: KWeld modding

tore off the resistor at R31. Looking at the other board it is labeled 657 or 650,000,000 ohms or 650 meg ohms, but that seems unlikely. Murphy got you, because that's a 6k57 0.1% precision resistor, which you most likely don't have in your drawer :-) That's part of the internal voltage reference g...
by tatus1969
Oct 09 2019 10:40am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

As a side measure, something that I have assumed is that all the caps are charging to the same voltage and actually balancing. I don't really know if that's true or not. The module does balancing, but it does it in a way that it equalizes the voltages across the capacitors (within a few ten millivo...
by tatus1969
Oct 08 2019 9:41am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

flippy wrote:
Oct 08 2019 9:36am
does the thicker leads also help with the cable length performance
They help reduce resistance and increase current, but the inductance doesn't change and therefore the system's current limit. These are actually also longer, 650mm instead of the stock 400mm.
by tatus1969
Oct 08 2019 9:24am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

Just wanted to share a piece of work with you that I am doing for a customer. These teflon handles 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.
IMG_20191008_161404.jpg
IMG_20191008_161404.jpg (101.74 KiB) Viewed 134 times
by tatus1969
Oct 08 2019 4:21am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

Perspective is everything... Not risk adverse: Colin Furze... https://www.youtube.com/watch?v=s4QBhNkaAk8 https://www.youtube.com/watch?v=LDM9aXVAoOw Risk adverse: Sloooooooow drivers... https://www.youtube.com/watch?v=hnml1rxiyIw Guess which one applies to me? I'm definitely of the first category....
by tatus1969
Oct 07 2019 4:46am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I've put lots of stuff in series and they work OK. That approach would be suitable for stuff that is not potentially dangerous like ultracaps or Lipos, but in this case I have to raise the :warn: :warn: flag again and strongly discourage from doing this. Please don't treat this as an offense toward...
by tatus1969
Oct 03 2019 3:43am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I have purchased a second super cap board so I can run them in series for more voltage. I want to mess with using my many LIPO packs as a power source, but they are all 4S or larger which isn't compatible with a single super cap board...as I demonstrated previously. My existing super cap board will...
by tatus1969
Oct 01 2019 3:57am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: K-weld super cap board experiment with over volting

WARNING: Do this at your own risk and frankly I recommend that you don't!!! WARNING: Please do not do this at all, this is very dangerous and can even lead to permanent injury! These caps can break down violently when being charged beyond their rated voltage! What can legit Maxwell caps handle? [.....
by tatus1969
Sep 17 2019 5:01am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

Can you figure out what might be wrong? The voltage is absolutely okay, and if the welder makes consistent welds as well then I suspect an entirely different problem. Do you have the firmware updater so that I can send you two different firmware images for testing? I'm varying the 'short' detection...
by tatus1969
Sep 16 2019 12:33pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

@tatus1969. Perfect. Thanks for info! This is a well documented thing and there is a paper (among several) from a Chinese searcher in a university I can't remember, detailing scientifically his findings. I will post a link to it soon. Traveling overseas now with only my phone and missing my desktop...
by tatus1969
Sep 16 2019 8:18am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

Question for Kweld's designer: Do you have any plans for adding a function in a future release that would switch the polarity half way through the welding cycle? As I am sure you know, DC spot welders don't form a similar nugget under the anode and the cathode for reasons we do not need to get into...
by tatus1969
Sep 10 2019 5:28am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

Can you figure out what might be wrong? The voltage is absolutely okay, and if the welder makes consistent welds as well then I suspect an entirely different problem. Do you have the firmware updater so that I can send you two different firmware images for testing? I'm varying the 'short' detection...
by tatus1969
Aug 27 2019 4:39am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld -

A right size resistor to limit current? Longer avg6 batteryleads and or smaller and worse connectors :mrgreen:. Not recomended mut if you keep them under max allowed lenghts if will loose some current.. Adding resistance in whatever way isn't recommended as it only produces more heat. Adding cable ...
by tatus1969
Aug 26 2019 7:55am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld -

Doubling capacity halves the C-rate for given current, or doubles current at the same C-rate. That's right but doesn't show the full picture. kWeld does basically short circuit the battery when pulsing, and the amount of current is directly given by Ohm's law: voltage stays constant when parallelin...
by tatus1969
Aug 26 2019 7:49am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I have moved over to the recommended Turnigy nano-tech 5000mah 3S 65~130C Lipo Pack for my Kweld. But I still cannot get good welds for the thicker .3mm nickel. The highest Joule I can get at this time is 62.5 ...after that I get an undercurrent message. Has anyone tried these Turnigy packs in para...
by tatus1969
Aug 13 2019 4:37am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

Is this "REMOVE SHORT" error cause only possible if this diode is somehow damaged (even if it looks ok)? If so, can it be easily replaced with an ordinary soldering iron? I need to order from you new electrodes, so if indeed I should replace this diode for stopping the error, maybe you can send me ...
by tatus1969
Aug 11 2019 6:45am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

If I disconnect the fuse (from the electrode side) and connect it again it stops giving "REMOVE SHORT" and it welds without problems. Any other ideas? Please do not trigger welding pulses without a replacement in place, this diode is protecting the switching MOSFETs from inductive kickback energy t...
by tatus1969
Aug 07 2019 3:49am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I have about 50cm 4AWG pure copper cable on the input. Should i shorten them because of inductance? What is the downside of worse inductance? I'd rather not because of the size of the car battery :) What a wonderful piece of welder :) Thanks 8) I am explaining the theory behind wire inductance in d...
by tatus1969
Jul 24 2019 3:08am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

eikido wrote:
Jul 23 2019 5:04pm
why not go with 0.2mm directly?
One good reason: less thick nickel means less required energy, which means less thermal stress for the battery.
by tatus1969
Jul 23 2019 7:15am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

Will someone please be kind and explain why something like kSupply exists? Why can't i just connect an appropriate/cheap power supply up to 8.1v to the kCap? However 2s 18650 wouldn't work->4.2x2=8.4v? The main reason why I developed that module was that I realized that the welder not only requires...
by tatus1969
Jul 04 2019 12:16pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I am currently building a pack using .2mm nickel. I have to crank the Kweld up to 125j for good welds and as a result the electrodes and their lead wires get pretty hot after just 4 spot welds and I have to let them cool off. Is this setting normal for .2mm nickel? And what about the heat in the el...
by tatus1969
Jun 17 2019 5:42am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I did that to both green and red graphenes, and the problem is the same, usually only one out of 6 gets unsticked, but that is probably from the heat, I once put my finger on the terminal and did a weld and it got hot for a really short time If you have disassembled one of the red ones on your desk...
by tatus1969
Jun 17 2019 3:03am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I actually bought the ones you recommended, calibrated the welder and the 2nd day of welding they broke beyond repair Which exact battery model is that? For example, I know from other customers, that the green Hobbyking Graphene cannot be recommended as the cell interconnects seem to be too weak. I...
by tatus1969
Jun 14 2019 4:32am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 864
Views: 100739

Re: kWeld - "Next level" DIY battery spot welder

I keep blowing my lipos, will i reduce the time required to make the weld by increasing their voltage? And there by reducing the heat and stress on the thin aluminum terminals Im currently at 3s and can make a 5s batters from the cells I have left that are not broken (all the same 5ah 75c panther) ...