There is a new software version 3.3.3 available.


  • fixes the slow progress bar drawing problem on “Auto Pulse” mode that sometimes occured.

It is available on my Github: Arduino Spot Welder V3.3.3 Software

What it does

When you use the Spot Welder in Auto Pulse mode you can set the delay time in the menu of the welder. For example if you set it to 1.5 seconds you can touch the nickel strip with both welding tips and after 1.5 seconds the pulse will be activated.

During this 1.5 seconds the welder will display a progress bar on the screen that acts kind of like a count down until the weld happens. But sometimes this progress bar took way longer than the set 1.5 seconds to finish. This problem seems to be caused by the latest SSD1306 display library.

With the code improvement in V3.3.3 the delay will always be exactley the delay time that was set.

4 thoughts on “New Software Version 3.3.3 available

  1. bob mutch says:

    Just a couple of questions about your spot welder. 1. With the malectric welder the adjustment for different welds is in time (ms). I’m just wondering if there will be a difference in the weld energy used in each weld when your battery is fully charged and when the battery is close to the LVC? or will the setting of 50ms delivery the same energy from the first weld when the battery is fully charged to the last weld when the battery is as discharged as the system allows?

    2. When you change from an approved LiPo battery to an approved SLA battery will the same 50ms deliver the same energy to each weld with the two different batteries?

    • Marc Schoenfleisch says:

      1. If your battery is empty the weld energy will be a bit less with the same pulse time setting compared to a fully charged battery. But with a car battery you can do a few thousdand welds before its empty. I recommend to charge it after every battery build, because thats best for the battery lifetime. And then you only use it in the top 70 – 100 % state of charge and never have to worry about changing the pulse time setting.

      2. When changing the battery you need to adjust the pulse time setting for the new battery. The welder only controlls the time. The Amps depend on the battery used.

      • bob mutch says:

        >>> And then you only use it in the top 70 – 100 % state of charge and never have to worry about changing the pulse time setting.

        Ok so between 60% and 100% SOC on an approved battery there is no noticeable different in weld energy?

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