How Alibaba’s Server‑Embedded Lithium BBU Revolutionizes Data Center Power Efficiency

Since the launch of the Double 11 shopping festival in 2009, Alibaba’s data centers have processed billions of transactions, relying on hundreds of thousands of servers. To lower data‑center PUE and improve power efficiency, Alibaba integrated lithium Battery Backup Units (BBU) inside servers, forming a distributed BBU system across the entire facility.

This approach makes Alibaba the first domestic internet company to provide server‑level backup power, joining Google and Microsoft in possessing such technology.

Traditional data‑center backup power relies on centralized UPS units with lead‑acid batteries, which suffer from four major drawbacks: a single UPS failure can affect thousands of servers, low conversion efficiency, high capital and operational costs due to over‑provisioned infrastructure, and labor‑intensive maintenance of lead‑acid batteries.

Alibaba’s design uses a 12 V lithium battery that activates instantly when external power is lost, delivering up to 99% efficiency—about 8% higher than conventional UPS or 240 V DC solutions—and reducing PUE by 10%–15%.

Because the BBU is installed inside each server, it can be procured and deployed together with the server, eliminating idle UPS capacity, cutting capital expenses, and accelerating data‑center delivery by roughly 15%.

For a typical 10 kW data center, annual UPS operating costs of tens of millions of yuan and upfront UPS and distribution equipment investments can be fully avoided. The lithium batteries also have a lifespan of 10–15 years, compared with 4–6 years for lead‑acid batteries, halving long‑term costs.

Managing tens of thousands of batteries presents a significant challenge. Alibaba leverages the same PSU interface protocol for the BBU, allowing the existing server management platform to locate and replace faulty units quickly, mirroring the reliability of automotive battery‑management systems like those in Tesla vehicles.

Since 2011, Alibaba has continuously upgraded its data‑center technologies—from the “Scorpio” project for full‑rack servers to the world’s first immersion‑cooled server clusters in 2017—positioning the new lithium BBU servers as the next breakthrough in data‑center power architecture.