Three different Aluminum alloys and tempers and one type of steel alloy were originally selected as potential candidates for qualification evaluation. The key design related requirements for material characteristics were strength, electrical resistance, stress corrosion cracking, and corrosion ratings; the last two requirements were necessary for metallic materials destined for exposure to harsh outer space environment. Weldability of those materials was further evaluated in correlation to selected welding tab material and welding tab designs. Direct processing parameters such as welding pulse energy levels, force and welding tab dimensional characteristics/design including surface finish were established based on capability of available robotic welding machine.

Finally the combination of materials that resulted in the batch of weldments with highest quality characteristics, weldments geometry, penetration depth, lack of deficiencies such as cracks, voids and expulsion features was exposed to thermal stress environment derived from the actual                                                                                                                                                                                                                                                      space program requirements. Metallurgical evaluation of weldments prior and after thermal stress was used for establishing the reliability of the processing representative of all elements integrated into the battery production.

In conclusion, the result of this experimentation revealed the most reliable material type for the bus bar, surface preparation, pulse characteristics, electrode conditioning and welding tab design that met all requirements for electrical and mechanical battery modules design.