Investing.com -- Fluence Energy (NASDAQ: FLNC) shares jumped 51% Monday after Siemens published a reference design for an NVIDIA DSX Vera Rubin NVL72 system that includes Fluence's SmartStack battery energy storage system as part of the electrical architecture for a roughly 103 MW AI factory.

The design specifies a 2-3 hour battery configuration, above prior assumptions of approximately 1 hour. Fluence is the only named BESS partner across seven infrastructure OEM designs in the NVIDIA ecosystem.

The Siemens reference design includes the full electrical architecture, bill of materials, and microgrid controls for the AI facility. The longer battery duration specification suggests potential upside compared to earlier market expectations.

Mizuho analyst Maheep Mandloi downplayed the news, saying, "... the DSX ecosystem is crowded and non-exclusive (multiple partners) and we already assume a 10% market share for FLNC BESS in data centers." The firm maintained its Underperform rating and $15 price target on the stock.

Fluence provides energy storage products and services for utilities and commercial customers. The company's SmartStack system integrates battery storage technology with software controls for grid-scale applications.