Battery Spot Welder Recommendations

• 

  iamherenow on 07/03/2023 - 14:36

  +1

  Sounds expensive. Why not use soldering iron? As long as you use flux on the battery end it's quick and there will be minimal heat transfer to the battery.

  • 

    impoze on 07/03/2023 - 14:39

    +3

    i don't think soldering is meant for making 18650 packs

    • 

      trapper on 07/03/2023 - 14:46

      You said you were repairing some batteries though.

      If you are planning to make a large pack then it might make sense to buy or make a spot welder, but for small jobs just solder them.

    • 

      iamherenow on 07/03/2023 - 14:46

      +1

      It's how i've soldered 18650s. I'm not aware of any issues with it.

      • 

        impoze on 07/03/2023 - 15:10

        thanks, I'll take a look

        • 

          afoveht on 07/03/2023 - 19:34

          @impoze: If they have tabs and you are okay with an iron then consider soldering them. If they don't have tabs then don't even try as you will very likely hurt yourself.

          • 

            impoze on 07/03/2023 - 20:27

            @afoveht: ok, attempting to repair LG A9 battery, i've opened it up and it's a 7S1P configuration

            https://www.youtube.com/watch?v=K19j4ohMnmg

            by tabs, are you referring to the pre-existing nickel strips?

            • 

              afoveht on 07/03/2023 - 22:49

              @impoze: Yes. You don't want to be putting heat into the cell - it's a recipe for disaster.

• 

  trapper on 07/03/2023 - 14:43

  +2

  You can just solder them, just be quick so the heat doesn't build up too much.

  You will need to use flux to get the solder to stick to the ends of the cells.

• 

  websterp on 07/03/2023 - 14:53

  If you are welding thin nickel strips and for occasional use any of those are(these are just glorified power banks modified to deliver a large current for a fraction of a second) fine but if your plan is to make large battery packs consisting of 10s or hundreds of 18650s and plan to use thicker strips for high current handling then have a look at Sunkko spot welders on Aliexpress. They have a large range so you can choose the right model depending on your budget and use case. Their welders are inexpensive and haven't had any issues with mine.

  Just noticed they also have a presence in Australia: https://www.vevor.com.au/spot-welder-c_10076

  • 

    impoze on 07/03/2023 - 15:56

    that looks a lot more useful than these portable ones for similar price,

    thanks

  • 

    lgacb08 on 07/03/2023 - 19:02

    I wouldn't go sunko path, last time I checked kweld or malectrics are the best options but will set you back $300 easy and requiring a bit of assembly.

• 

  rumblytangara on 07/03/2023 - 15:28

  I've used an iron to very quickly solder onto 18650 cells, when I haven't been able to find cells with pre-existing solder tabs. Only done it a handful of times, with no noticeable ill effects.

  • 

    impoze on 07/03/2023 - 16:17

    so just solder the old nickel strips when replacing a cell?

    • 

      rumblytangara on 07/03/2023 - 17:13

      I've just soldered bare wire onto the cells.

    • 

      websterp on 07/03/2023 - 17:35

      If you are only soldering a battery or two you can always use a soldering iron and can easily substitute nickel strips with a cable like this one or a thick enough bare wire as mentioned by the previous poster. You can't go wrong using a lead based solder with a resin core and a 40W+ soldering iron/station but you need to get the soldering done within few seconds and if you want to have a second go just make sure the battery has cooled down from the previous attempt. Optionally for quick adhesion you can lightly sand the battery terminals and apply some flux on both surfaces (terminal and cable end) before soldering.

• 

  altomic on 07/03/2023 - 17:46

  Have a look at this post from january
  https://www.ozbargain.com.au/node/751183