Search found 349 matches

by tatus1969
Jun 22 2020 5:07am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

You can also try spotweld pulse with long strip. Like 10-30cm or so with electrodes on oposite ends without a cell. That could give most accurate results regarding resistance difference of different materials. Very clever idea. I will try it. Thanks for the suggestion Yep. It worked. It makes sense...
by tatus1969
Jun 09 2020 5:23am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

I think I know the answer but I wanted to ask in case I’m wrong. Tonight I was spot welding .25 mm nickel plated copper strips (about 65 - 75 joules). I was curious why I encountered an “over current” message when I used two Lipo batteries in parallel instead of using just one Lipo battery. I have ...
by tatus1969
May 21 2020 9:28am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

Re: AGM Battery Results - "Next level" DIY battery spot welder

ODYSSEY Extreme PC925 12V Auto Battery -I 1389A That sounds like an amazing option for kWeld, since that battery delivers more than enough current while still being considerably smaller than a regular 65AH/100AH starter battery (at least what I can tell from your picture). Please tell me the amount...
by tatus1969
May 18 2020 5:22am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

garolittle wrote:
May 16 2020 1:18pm
1 Pack
R=2.20 mr
Std=29.2
I=1530A
T=32.1C

How do these numbers look? Am I ready to go? Thanks for all the great advice.
Perfect!
by tatus1969
May 16 2020 5:21am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

The calibration numbers I got out of it were: 1 Pack R=2.37mR 2 Packs R= 2.19mR Very nice. Low resistance numbers. I guess that I need to explain something here :D The displayed resistance from the SHORT calibration step is not the measured internal resistance of the battery, but the resistance of ...
by tatus1969
May 14 2020 3:05am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

XT90 is already too weak to carry the current from a single battery (~1400A). In fact, given the ratings of these batteries, both AWG10 and XT90 are not appropriate. Running up to 2000 amps through them will probably cause them to melt -keep in mind: 41% more current results in doubled conduction lo...
by tatus1969
May 13 2020 3:36am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

Got new Kweld. Awesome machine. Followed setup instructions for calibration but I do not get a resistance reading after pressing the electrodes firmly together and pressing the knob when the “Short” message is displayed. I can feel the pulse but instead of an IR rating it just displays “10J”. Any i...
by tatus1969
May 11 2020 4:29am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

For the power source, I ordered two Turnigy Nano-tech 5000mAh batteries, with the intent to run them in parallel to reduce the 'abuse' on each battery, but I've read what seem to be conflicting information. I've read posts saying that you can't calibrate it with both attached, but it'll work fine. ...
by tatus1969
Apr 29 2020 3:57am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

leads get pretty warm and so does the battery. I don't have a good feel yet for how warm is too warm and thus time for a cool-down. Please make sure the battery doesn't exceed 50degC in order not to further reduce its lifetime. In most cases, the necessary cooling periods for the electrodes are eno...
by tatus1969
Apr 27 2020 12:12pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

Seakane wrote:
Apr 27 2020 11:01am
Is it okay that my R value is lower than the manual's range?
Yes, that mistake is actually not with you but the manual. That number is from the previous electrode design and I haven't been able to make up the time to update it. Your result is spot on.
by tatus1969
Apr 27 2020 6:23am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

@tatus1969, what are your thoughts on Headway LiFePo4 cells and the kWeld? Yes these are much safer and can be used. You'll need to run the calculations with regards to voltage (should be ~ 10 to 15V) and the pack's internal resistance (~ 3 to 5 milliohms) however, and that's where it becomes trick...
by tatus1969
Apr 27 2020 6:17am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

R = 2.37mR (typically between 2.5 and 3.0. Any problem with my value?) Looking good, but you shouldn't get such varying results. Please check all nuts and bolts, also the electrode set screws (but be careful there as they thread into copper). You might also want to clean the electrode tips with san...
by tatus1969
Apr 23 2020 11:18am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

hi guys, any idea why I'm getting only around 1000A with these batteries (2S, 7500mAh, 90C rated)? Yours is a 2S model, the 1400A figure is for a comparable battery with 3 cells in series. That's why your current is lower. The ESR measurement is certainly way off, these packs have a few milliohms o...
by tatus1969
Apr 23 2020 4:23am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

I haven't used Pb batteries myself, but have collected feedback from other users on the kWeld product page. A 65AH battery (the 'normal' size for cars, likely also your Subaro) seems to be in the 1000A region, and larger 100AH models are around 1400A. :warn: :warn: Can I make a poll from you guys us...
by tatus1969
Apr 22 2020 2:16am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

Any thoughts on using my NOCO GB70 Jump starter as a power source? The unit specs are: 2000 peak Amps 56WHr Lipo (5000mAH @ 11.1v nominal) and this funny J3S rating of 15,700 (Joules in 3 seconds). The Joules number seems to indicate a continuous amps of about 450A Iny my opionion most of this is m...
by tatus1969
Apr 22 2020 2:06am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

Seakane wrote:
Apr 21 2020 1:15pm
Timeout
n=000001
E=-23.2J
t200.00m
I= 1344A
R=-0.02m
T= 29.4C
I repeat, this is *not* the result of a SHORT calibration step. That step uses a 10ms interval. Is it possible that you have a shorting link in the foot pedal terminals? That is not allowed during calibration.
by tatus1969
Apr 21 2020 4:09am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

Okay held the knob for the "open" part of the test and got the following values: Offs: 62 Std: 5.6 And: Ok No problem :-) And what was the result of the SHORT part? Still don't know why my resistance value was off from spec at -0.02 milli Ohmes, but judging by the lack of concern here, I think I wi...
by tatus1969
Apr 20 2020 7:29am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

The manual says I should see an "Offs" value between 50 and 100, typically. When I run the calibration I get no Offs value. After I press the knob, the "Open" prompt goes to "Short" without any information being displayed. According to the manual, post short test should yield a resistance value of ...
by tatus1969
Apr 19 2020 12:39pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

Timeout n=000004 E=-23.4J t200.00m I= 1340A R=-0.02m T= 29.4C That is a result from a regular welding pulse with shorted probes, which is why the cables get hot quickly. This also represents a huge demand from the battery and could damage it. Please revisit the kWeld operation manual to ensure that...
by tatus1969
Apr 18 2020 5:23am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

My calibration test process indicated "Timeout" That is the expected result from the SHORT calibration step. The kweld reported 1233A after the short and a duration > 200 msec. The current is perfect, but are you sure that it reported 200msec timeout during the calibration SHORT step? The programme...
by tatus1969
Apr 06 2020 8:27am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

I have a dedicated 12V AGM, 100AH battery, practically brand new (4 cycles). Is this adequate to power the K weld 'as is'? I don't have sufficient references with regards to AGM batteries. If that battery has a CCA rating, then it should be at least 700A. Deep cycle batteries are optimized towards ...
by tatus1969
Mar 31 2020 4:16am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

What about putting copper braid between the terminals, wouldn't that allow better electrical contact under less force ? But it would maybe oxidize over time ? (first post here, I've been lurking for a while, so... hello! :D ) Hi :-) could be worth a try. Anyhow, at the moment I'm also only giving e...
by tatus1969
Mar 30 2020 5:30am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

I am looking into the Maxwell capacitors. Would it be possible to simply make the series connection by clamping om busbars in and enclosure or is it necessary to weld or something similar? I don't recommend clamping, because at these current levels you'd need quite some clamping force, and you'll l...
by tatus1969
Mar 27 2020 7:40am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

1800amp is perfect, as long as the welder doesn't complain about overcurent (provided that you also have reduced the cables to 1m total!)
by tatus1969
Mar 26 2020 5:06am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1165
Views: 160932

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

Have a question regarding calibration. I use 3s4p spim08hp. The cable I use from the battery to kweld is 4 awg wire, length of 300mm, so in cable setting I adjusted it to 1.5m. But I get overcurrent during calibration, and 1563a? The voltage of the battery is 11.66v. Is my cable setting correct, is...