An Update on Lithium-ion Battery Use in Critical Facilities (Safety Rules)

Overview

The document compares Li-ion and VRLA qualitatively. Li-ion systems can reduce battery footprint by 50-75% against VRLA, weigh less and have roughly double the effective life, while VRLA batteries lose about 50% of life for every 10°C rise in temperature. A 2013 Ponemon study found UPS and battery failure to be the leading cause of data-centre downtime. The text also explains why UPS-grade cells differ from consumer cells.

Safety and fire-code requirements are the centre of gravity. The 2018 NFPA 1 Section 52.3 requirements apply to Li-ion systems above 20 kWh (about a 5-minute 50 kW UPS load): batteries need UL 1973 listing, an approved BMS supplied with the batteries, a listed non-combustible locked cabinet, automatic sprinklers and smoke detection. Relevant standards are IEC 62619 (industrial Li cells including BMS), IEC 62897, UN 38.3 and IEC 62281 for transport, IEC 62477-1, IEC 62040-1 and IEC 61439-1/2.

Chemistry selection weighs LFP, NMC and LMO against LCO. The UPS BMS is two-level: cell-level monitoring of voltage, temperature and current reports to a rack-level controller that manages system safety, balancing and switching. The paper recommends only UPS-manufacturer-approved battery systems. Code citations are to 2018 editions, so current fire-code thresholds should be re-verified during a project. The practical message is that battery selection is not only a chemistry choice but a decision about approved pairing with the UPS, listings and room-level fire protection.

Key points

1. Li-ion systems can reduce battery footprint by 50-75% versus VRLA, with lower weight and roughly double the effective life.
2. VRLA batteries lose about 50% of life for every 10°C rise in temperature.
3. A 2013 Ponemon study found UPS and battery failure to be the leading cause of data-centre downtime.
4. 2018 NFPA 1 Section 52.3 applies to Li-ion systems above 20 kWh (about a 5-minute 50 kW UPS load): UL 1973 listing, approved BMS supplied with the batteries, listed non-combustible locked cabinet, automatic sprinklers and smoke detection.
5. Relevant standards: IEC 62619 (industrial Li cells incl. BMS), IEC 62897, UN 38.3 and IEC 62281 (transport), IEC 62477-1, IEC 62040-1, IEC 61439-1/2.
6. The UPS BMS is two-level: cell-level monitoring of voltage, temperature and current reporting to a rack-level controller managing safety, balancing and switching.
7. Chemistry options are LFP, NMC, LMO versus LCO; only UPS-manufacturer-approved battery systems are recommended.

Using it in design

• Give the battery catalogue chemistry (LFP/NMC/LMO/VRLA), kWh per cabinet, UL 1973 / IEC 62619 listing, BMS level and approved UPS models.
• When total Li-ion energy in a room exceeds the fire-code threshold (for example 20 kWh), require sprinklers, smoke detection and a hazard mitigation analysis.
• Block pairing Li-ion cabinets with UPS models not on the vendor-approved list.
• Apply temperature derating to VRLA life estimates.

Who should read it

Designers choosing between Li-ion and VRLA in UPS battery rooms and checking fire-code compliance.

Related standards

• NFPA 1
• NFPA 855
• UL 1973
• UL 9540A
• IEC 62619
• IEC 62040-1
• UN 38.3
• IEEE 1679.1

Publication details

Authors

Vertiv

Publisher

Vertiv

Year

2018

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation