Lithium-Ion Battery Safety in UPS Applications: Facts vs. Fiction

Are Lithium-Ion UPS Batteries Actually Safe? Here’s What the Data Really Shows

By Molly Gross, Principal, Power Solutions, LLC

Li-ion batteries got a bad reputation from EV and consumer electronics fires. But UPS-grade lithium-ion is an entirely different product — with an entirely different safety profile.

Viral videos of cellphone fires and EV battery incidents created a stigma around lithium-ion batteries that followed the UPS industry into the data center. But UPS-grade lithium-ion batteries use fundamentally different chemistry, packaging, and safety systems than consumer devices. This whitepaper addresses the most common safety misconceptions, explains what causes thermal runaway and how modern UPS batteries prevent it, reviews the lithium-ion chemistries used in UPS batteries, and details the Battery Management Systems that make today’s Li-ion UPS batteries as safe as the VRLA batteries they replace. If your organization has hesitated on Li-ion UPS batteries due to safety concerns, this whitepaper has the answers. For the cost side of the decision, read our guide, Lithium-Ion UPS Batteries: A Complete Guide to TCO, Safety, and Making the Right Choice for Your Infrastructure. 

Whitepaper Summary

Q: What causes thermal runaway in lithium-ion batteries?

A: Thermal runaway occurs when a short circuit in a battery cell triggers a rapid chain reaction that produces heat, which can spread to adjacent cells. Proper installation, battery chemistry selection, cell and pack safety design, and Battery Management Systems greatly reduce the risk and keep a single-cell failure from spreading.

Q: Are lithium-ion batteries used in UPS systems the same as those in electric vehicles or phones?

A: No. UPS-grade lithium-ion batteries use chemistries selected for stability and service life. Schneider Electric uses NMC in its Galaxy and Smart-UPS Ultra/Modular Ultra lines and LFP in Smart-UPS Lithium-Ion models. Both are more thermally stable than the Lithium Cobalt Oxide (LCO) used in consumer devices, and UPS batteries add cell- and pack-level safety design, a multi-layered BMS, and independent
certification.

Q: How do Battery Management Systems (BMS) prevent lithium-ion battery fires?

A: BMS platforms monitor individual cell temperatures, balance charge across cells, detect fault conditions, and disconnect the affected battery module or cabinet before a problem can spread — providing multiple layers of active protection.

Q: What safety standards do lithium-ion UPS batteries meet?

A: Schneider Electric’s cells are certified to IEC 62133 and UN 38.3, and its battery modules to IEC 62619, UN 38.3, and UL 1973. UL 1973 and IEC 62619 both include thermal runaway testing, and installations follow NFPA 855.

Q: Are lithium-ion UPS batteries legal to use in data centers?

A: Yes. No major US city prohibits them. New York City and California regulate lithium-ion energy storage, including UPS batteries, through their fire and building codes and require listed, tested equipment such as UL 9540 systems. Galaxy UPS systems paired with Schneider Electric Galaxy Lithium-ion battery cabinets are offered as UL 9540 energy storage systems.

Q: Are lithium-ion batteries safer or more dangerous than VRLA batteries in UPS applications?

A: With the right chemistry, BMS, and installation, lithium-ion UPS batteries are as safe as VRLA and are an increasingly preferred option for data centers. Schneider Electric reports more than 500,000 Li-ion UPS units deployed with no reported safety incidents. Li-ion batteries also contain no lead.

Download this whitepaper.