Electrical Contact Resistance

The Electrical Contact Resistance at a metal to metal contact is primarily governed by: The surface structure can be further described by the surface flatness, surface oxidation and water adsorption. These joints in a battery pack will either be welded or bolted. Initially the easiest to think about is the bolted busbar joint. The bolt … Read more

Pre-Charge Resistor

When the battery pack contactors are closed onto a motor and inverter there will be an inrush of current into the inverter capacitor. This very high current is at a minimum likely to age the contactors, it could permanently damage the contactors. Therefore, when we closed the contactors on the battery pack we do this … Read more

Internal Resistance 101

electrical symbol showing single cell and internal resistance

Let’s take a tiny step and understand how IR is measured in the first place. How are resistances measured? A small current is injected into the component and voltage is measured across it and then resistance is calculated by R=V/I; yes! This is how a multimeter does its’ job; it’s not rocket science. There are … Read more

Cell Level Fusing

Accelonix cell wire bonding

When we connect cells in parallel to increase the capacity we might also want cell level fusing. This fusing being by definition designed to disconnect a cell that for some reason is sinking or delivering high currents. The fusing can be inside the cell and sealed or external to the cell, sometimes both internal and … Read more

Photo Etching

ACE busbars

Whether prototyping or creating busbars for production runs we often want high quality parts and this is where photo etching comes into it’s own. Advanced Chemical Etching take us through the process of photo etching and how this can be used to create high quality aluminium or copper parts. We are concentrating on busbars, but … Read more

Aluminium Busbar

Tesla Model Y 4680 Busbar

Electrical grade aluminum busbar material also known as ec grade aluminum busbar. 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 common grades of aluminum for electrical busbars: 1060 1100 1350 6063 6101 Cross-Sectional Area … Read more