Saturday, July 3, 2010


I have measured the ESR of my welder and its much lower than anticipated. The ESR of the welder bus bars at the front of the welder measures less than 0.0005 Ohm (500 micro Ohm). With such low resistance, this welder can produce astronomical currents and will only be limited by the resistance of the probe, wire and material being welded.
I am way behind schedule with my version 3 processor and spent most of my time getting the new welder built.

 Most companies and people out there that are welding A123's are very tight lipped about how they do it and I would like to get to the bottom of it!!! I'm  doing some experiments with inverted resistance welding and was wondering if there are some of you guys that would send me some of your old A123's to play with ??? I will post all my findings on here!!!


  1. My friend had some old ones, I will check to see if he still has them and will send your way if still needed for testing.

  2. I found out that both the negative and positive terminals contains nickel. The positive terminal is very thin so care has to be taken not to burn through it though. This welder should easily weld A123's. I have someone that is going to send me a couple but I will appreciate it if you can get me some more Swallaceok.

  3. I talked to a A123 seller in China. Here is the welding info that he got from A123:

    Pressure: 7kg force per electrode
    Squeeze: 250ms
    Weld Time: 5ms
    Weld Power: 5kA
    Hold: 250ms

    Positive terminal is 0.2mm Ni-200 laminated to 1.0mm Aluminium
    Negative terminal is 0.8mm Nickel plated steel

  4. Thanks for the information Mark!

  5. i got the date from a buddy that designed a caseing for a123 systems he said thay do a 5ms pulce at 1000a to clean the contact area and a 100a pulse for 1 sec to weld the tabs i got some lose cells new and the nickle plates that used to welld them fresh if u want i can send u some tabs to mess with and some batterys my emails let me know if u need some more info i will conferm the information

  6. The 1000A/100A numbers cannot be valid. The A123 cells are designed to generate well over 100A in normal operation. If 100A could generate enough heat to weld the tabs, then they could easily unweld themselves during normal operation.

  7. I have some cells I would be willing to send to you for testing if you still need them. Drop me a line at with your address and I'll ship them out when I get the chance.


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