Lithium battery copper busbar withstands current

Do you need a bus bar for your DIY lithium batteries?

We are continuing our deep dive into bus bars for our DIY lithium batteries. Bus bars (busbars) are short strips of conductive metal for high current electric connections. We are going to use some to connect the battery cells in our batteries. While the concept of a bus bar is simple, getting the right bus bar is nuanced.

How much current does a copper busbar need?

The current is an estimated continuous rating and plotted versus the cross-sectional area in mm 2. The gradient of the “straight line fit” shows that 5.9A/mm 2 is a rough estimate for copper busbar size. However, to be on the safe side of this I would initially size at 5A/mm 2 before doing the detailed electrothermal analysis.

What is a good size for a copper busbar?

The gradient of the “straight line fit” shows that 5.9A/mm 2 is a rough estimate for copper busbar size. However, to be on the safe side of this I would initially size at 5A/mm 2 before doing the detailed electrothermal analysis. An important aspect to consider in all busbar designs is to consider the environment and the materials.

What is the difference between copper and aluminium busbars?

Compared to copper busbars aluminium offers a weight and cost save, but requires an increase in cross-sectional area of ~62%. Hence aluminium busbars need more volume for packaging. The highest conductivity is achieved by high purity aluminium (purity of 99.9 wt% Al and higher) in soft temper.

Are copper bus bars corrosive?

Copper bus bars come in a variety of forms. Copper quickly corrodes when exposed to air. Therefore, many bus bars have a thin layer of non-corrosive material around them, such as tin. Coating copper is particularly common in corrosive environments, such as the ocean. So you’ll often see tinned copper as a marine-grade connector.

Are busbars good thermal conductors?

These should be a physical clip that is designed for the life of the pack and considers all of the above points and all environmental inputs. Busbars are good electrical and hence good thermal conductors. This means they can conduct heat away or to other components.

Busbars are the main electrical connections between cells, modules and connect all of the HV system to the outlet connector. Normally made from copper or aluminium. Careful …