Wire Compacting and Multi-Stranded Wires for Electric Vehicles

Apr 27, 2022


By Bryce Bytheway

Micro Welding Consultant


Wire compacting has become more and more popular in recent years as manufacturers scramble to find a better solution for wire connection management. The problem that many encounter is when attempting to weld multi-stranded wire, it can often be difficult to capture all the strands in the electrical connection, thus increasing electrical resistivity and reducing overall effectiveness and weld consistency. The solution? Wire compacting!

What is wire compacting? 

Using high-tech welding technology, a production team can take a multi-stranded wire and weld all of the individual strands of wire together into one, easy-to-manage singularity. Thus, the production team works with only one single-bonded bundle instead of many individual strands. Visit the Sunstone YouTube channel to view a number of examples of stranded wire compacting.

How does wire compacting benefit the EV production process? 

Now that the multi-stranded wire has been reduced to a single bonded bundle, the production team can work with it more easily and with greater consistency. Additionally, it is much easier to bond the wire to an electrical connector with results that are guaranteed to be clean and consistent. The connector can also be abandoned altogether and two separate wires can easily be bonded together without the use of a connector, which adds time and expense to the production process.

What welding technology works best? 

There are a handful of different welding systems and technologies that can be utilized, including resistance welding and even ultra sonic welding. However, overall high frequency (HF) inverter resistance welding systems provide results that are clean and trackable. HF Inverters are the pinnacle of resistance welding technology as they offer high power, smooth welds, adjustable weld durations, and full closed-loop weld monitoring. Linear DC and capacitive discharge (CD) welders can also be used for wire compacting though to a lesser degree.  

With a resistance welder, a custom weld head is utilized to hold the stranded wire in place during the welding process. The weld head and electrode setup holds all the individual strands of wire, compacts them, and applies the welding energy as it compacts them further. This creates the bond between all of the strands and pulls them into one bonded bundle.  

Industries and applications that benefit from wire compacting: 

Using higher powered HF Inverters allows the bonding of thicker wires and cables. Electric vehicle (EV) manufacturing has become a big proponent of wire compacting as the ability to assure lower resistance in the electrical connections and greater consistency in end results improves. Lower resistance and greater consistency are two key components in providing quality electric vehicles. Other industries include standard electronics, wire to PCB pad connections, wire-to-wire connections, and battery pack manufacturing.  


While true wire compacting is still in its infancy, the benefits are such that it propels the industry forward with some of the greatest minds in resistance welding technology pushing the boundaries further. Sunstone is at the forefront of those committed to providing top notch welding systems and is ready to be your partner in your micro welding needs.