Battery use is expanding beyond electric vehicles and energy storage systems to server racks as AI data centres push rack power density higher. Facility-level uninterruptible power supplies are seen as less able to handle rapid power swings, lifting demand for rack-level battery backup units, or BBUs, defined in open rack standards such as OCP Open Rack V3. Samsung SDI forecasts the global BBU market at $800 million this year, up more than 70 percent, while suppliers prepare new products and production.

South Korea\'s three major battery makers posted weak first-quarter results. LG Energy Solution and Samsung SDI swung to operating losses, and SK On is also expected to remain in the red. Brokerages see the first quarter as a cyclical trough and expect a shift to profitability from the second quarter as energy storage system sales ramp up and electric-vehicle demand recovers. Key variables include the pace of ESS revenue recognition and normalization of North American production.