The compared techniques are resistance spot welding, laser beam welding and ultrasonic welding. The performance was evaluated in terms of numerous factors such as production cost, degree of automation and weld quality. All three methods are tried and proven to function in the production of battery applications.
The low melting point of lead means the welder can easily melt the base metal and filler metal with an oxy-acetylene torch to achieve a solid weld. TIG welding is also suitable for welding lead due to the capability of this process to weld at very low amperages. Stick welding is unsuitable for welding lead because the SMAW process is too hot.
Lead welding is used in the construction industry, particularly for applications involving lead sheets or lead-coated materials. Examples include roofing, flashing, and waterproofing systems, where lead’s malleability and corrosion resistance make it a preferred choice.
And that means lead acid batteries aren’t either! The assembly of reliable, high-performance lead-acid batteries for use in automotive, marine and industrial applications, however, poses a significant challenge. The basic application involves welding a series of lead castings or “tombstones” which make up the cores of the individual battery cells.
The findings are applicable to all kinds of battery cell casings. Additionally, the three welding techniques are compared quantitatively in terms of ultimate tensile strength, heat input into a battery cell caused by the welding process, and electrical contact resistance.
Battery cells are most often put into modules or packs when produced for electrically driven vehicles. The variable of greatest influence when welding battery packs is the contact resistance between the cell and the connection tab. It is crucial to minimize this variable as much as possible to prevent energy loss in the form of heat generation.