Batteries were arranged with 3 cell series, and 25 parallel(3s25p). The cells were spot-welded using the Spot welder, which I built during my last project. The 12V output of the battery can be connected to an inverter to convert the DC voltage into mains AC voltage. Interconnections of the components in the system are illustrated below.

Power Diagram

I used Fusion360 to design the 3D printed enclosure by arranging all the parts in the system beforehand. This allowed me to optimize the component placement in tight space. Due to the limited space, steady airflow is critical for cooling the modules during operation, hence the 6mm cooling fan on the top.