This study used historical data from a Park & Ride facility in Amsterdam to build a validated computer (Python) model to optimize battery and grid connection sizing. The case study modelled is equipped with 8 EV chargers (16 connections), an on-site supplementary battery, and a limited capacity grid connection. This model was then used to optimize the battery energy storage capacity and grid connection capacity for minimal annualized investment, using a future proof monthly load profile. A variety of battery control strategies were simulated using both the optimal system sizing and the current system sizing. The results were compared and a recommended control strategy presented, considering a number of performance metrics.