With a century-long application history, lead-acid batteries are classic core equipment for UPS backup power in data centers with a highly mature technical system. Compared with new energy storage batteries, they feature predictable performance attenuation and controllable failure modes without sudden faults, adapting to the 7×24-hour uninterrupted operation of data centers. Mainstream valve-regulated sealed lead-acid batteries are maintenance-free, suitable for unattended computer rooms, and have excellent high and low temperature adaptability. With stable floating charging performance and reliable discharge capacity, they remain the mainstream backup energy storage solution for data centers of all scales.