Battery energy storage system (BESS) investors typically seek grid connections at locations determined by non-grid factors

such as land availability, creating potential mismatches with optimal grid integration points. Compounding this challenge, tra-

ditional hosting capacity assessments rely on conservative worst-case scenarios that significantly underestimate viable BESS

capacities and reduce investment attractiveness. This paper presents a Multi-Period Quadratic Constraint Optimal Power Flow

framework for one-year hourly operations that evaluates cooperative investment models where investors grant operational control

to distribution system operators, enabling mutual benefits through larger installations and optimized grid operation. The convex

optimization leads to fast solving with approximately 160 seconds. The methodology integrates state-of-charge temporal depen-

dencies, degradation costs, and penalty terms to model comprehensive BESS operation while enforcing voltage, thermal line,

and power balance constraints. Applied to the CIGRE MV benchmark network with 2024 market data, the framework system-

atically compares standalone arbitrage operation against grid-integrated scenarios through Net Present Value analysis. Results

identify an optimal BESS capacity of 30 MWh at a single connection point, with network bottlenecks limiting further capacity

expansion. Although line congestion hours increase substantially as capacity grows, the configuration remains economically at-

tractive, demonstrating that cooperative operational frameworks unlock significant value for both investors and grid operators

while maintaining system reliability.