Virtues of Megacasting

The six megapresses being installed at the Anna Engine Plant in Ohio allow Honda to create a simpler structure for the aluminum diecast battery cover, going from more than 60 parts to five. 3D friction stir welding, which can weld different materials of different thickness, is used for high quality joints which improves production efficiency. There is less heat and deformation than arc welding. The combination of megacasting and stir welding results in a case that is lighter and 6 percent thinner. It can have a thinner protective case because the body structure of the vehicle was designed to disperse the impact of a collision, rerouting the force around the vehicle.

A thinner case makes more room for the battery itself in a vehicle with a low floor, ample cabin space, a range of about 300 miles. Honda has also developed a thermal management system to use less energy to keep the cabin warm in cold weather. Honda also wants to limit the degradation of the range to less than 10 percent after 10 years of use.

The batteries, which are lithium-ion pouches as opposed to prismatic cells, will be produced in a new joint venture plant with LG Energy Solution in Marysville that should be completed by the end of the year. It adopts a flex-cell layout and highly automated process to adjust volume to demand for medium or large battery cases.  

Retooling for the Future

Honda is updating the vehicle assembly plant in Marysville, making it flexible enough to make vehicles with internal combustion engines, hybrids, and battery electric vehicles all on the same line. It will start making an Acura EV in late 2025 based on the Acura Performance EV concept, and riding on a new architecture. The new flexible line will run alongside the current one that builds the Acura Integra and TLX and the Honda Accord and Accord Hybrid.

Honda will use a new CDC (Constant Direct Current Chopping) joining technology for spot welding of the body frame. Honda says it is first to do so, and the use of CDC gives the frame greater rigidity with higher tensile but lighter materials. Difficult materials can be welded together, resulting in a thicker weld with less splatter. And Honda can install the CDC welding gun onto existing robots. Honda will start using it on 0 Series vehicles and expand the technique to all future vehicles, regardless of powertrain.

The Ohio plant will make the 0 Series as well as the Sony Afeela. Honda’s first EVs, the 2024 Honda Prologue and Acura ZDX SUVs, stemmed from a partnership with GM. While designed by Honda, they use GM’s Ultium battery and EV platform and are made in a GM plant. 

Next-Gen EVs in Canada