First spotwelded battery by Bart

Författare: Lars Lindmark | Datum: 7 oktober, 2022 | Projekt: Projekt #008| Nyckelord: #008-5, Bart, spotwelding

 

I’ve just finished my first spot welded battery. The spot welding is still tricky, but I seem to get better at it.
Sometimes I burned a hole through the zinc plate – or even into the battery, I think because of a bad copper electrode-to-zinc strip contact causing a too high temperature (fast oxidation).
I have now used full zinc strip, but it is difficult to make a strong connection at the minus side of the battery. I therefore started spot welding at the edges of the zinc strips, where the temperature rises quicker and a stronger connection was made. In the future I will try this zinc strip, because it has a small slit where the centre of the battery top will be, so that that area will become hotter quicker.
I read online that hot glue was recommended to connect the batteries, but I do not recommend it. It is a bit too weak for a glue and then the battery falls apart. Instead, these battery spacers are more robust. Off course, you can still use hot glue in between for heat transport.

The battery pack uses a a simple and cheap BMS  with configuration  4p13s (48 V). With this model you get the overvoltage protection of the overall pack from charger (only charges to 54 Volt), and the undervoltage protection from the controller (stops working at 42 Volt).

Builder: Bart Oostenrijk