Johnson Controls, Inc., Milwaukee, WI, USA

A 300-kW, 600-kWh BESS was developed by Johnson Controls as a turn-key, customer-side-of-the-meter demonstration project. It was placed in service at an in-house brass foundry with a base load of about 1.1 MW with 4 or 5 daily peaks to 

5 to 1.6 MW. The peak loads corresponded to the melt cycles of two, inductively heated furnaces that were operated at the foundry. The BESS was used for peak 

The battery was assembled from VRLA modules of a gelled-electrolyte design, which had excellent deep-discharge capabilities. The modules had lead-coated copper terminals and bus bars, a status indicator that warned if the SoC dropped below 20%, and an internal air manifold for thermal management. The facility contained 64 modules connected in series to produce a 384-V, 1500-Ah battery. 

The power-conditioning system was a self-commutated, dual-bridge, six-pulse design. The a.c. output was three-phase, 480 Vac. The BESS typically operated in a constant-power output mode. Charging of the battery was conducted initially at constant power and then finished at constant voltage [20]. 

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