Resistance Welding for Cell Interconnect

Effective battery pack design must encompass manufacturing practices that will withstand the rigors of deployment within a customer’s device. To this end, Aved Electronics has determined to employ resistance welding for intercell connections within our battery pack designs.

Aved has invested in Unitek Miyachi Dual Pulse power supplies with Unitek’s proprietary EZ Air pneumatic weld heads for our resistance welding equipment. These state of the art welders provide consistent, refined and controlled results for this critical component in pack manufacturing.

Resistance welding is the most cost-effective method for joining tabs on a wide range of battery types and sizes. With fast rise times, closed loop feedback control, polarity switching, and options for displacement and force sensing, the process can be finely tuned and monitored to ensure both high quality and yield. For nickel tab thicknesses up to 0.007 inches, the tab can be welded without modification. Aved prefers to use Nickel 210 materials for good electrical conductivity and bonding to the host surface of the cell cans. Beyond this thickness of 0.007 inches, and to prevent electrical shunting and excessive electrode wear, a slot and projections are placed in the tab as part of the stamping or formation process for the tabs. The projections act not only as energy concentrators for the weld but also greatly increase electrode lifetimes.
Aved’s design engineers consider the IR created in multicell connections for the overall performance quality of the pack design. Instron testing can be conducted to promote the ideal strength of weld and energy pulse investigations determine optimal tab geometry for lowest IR in the constructions.