Battery Pack Architecture
The work
Rameez led the architectural studies for the world’s first iron-air battery packs in a 40-foot container, mapping cost, field deployment time, battery sensor integration and the auxiliary loads the system draws at the grid. First-order sensitivity calculations set the fan sizing needed to evacuate hydrogen gas and hold the cells thermally stable, while structural load work set how many cells a pack could carry against trailer weight limits and the risk of electrolyte leaks.
Much of the architecture is safety architecture: conforming to UL 9540 and NFPA 855 for hydrogen venting, material selection, thermal runaway containment and control system coordination. Where the risk was highest, he wrote the memos that forced decisions to be made rather than deferred, on fire suppression detection and on electrolyte containment.
Alpha 1 build, the first ever prototype pack that met system-level requirements, unlocked numerous learnings, and challenged some theoretical assumptions to allow for improved cell, module, and pack architecture revisions
Architectural trade-offs allowed for an early understanding of charge asymmetry. This was driven by the cell voltage difference between charge and discharge, resulting in a DCDC combiner that was custom designed.
40ft battery packs placed on 6 points only, to allow for simpler and faster field install. The cable connecting each pack was high-voltage (1.5 kV), fuse and contactor protected.
Front vents for thermal intake and H2 dilution intake.
Image: Form Energy