GB 44240-2024: China’s first mandatory safety standard for energy storage batteries

#From recommended to mandatory

Before GB 44240, safety requirements for energy storage batteries in China were set by recommended standards (GB/T). GB 44240-2024, Safety requirements for lithium secondary cells and batteries used in electrical energy storage systems, makes them mandatory.

#Scope

The standard covers lithium cells and battery packs used in electrical energy storage systems, including telecom backup, central emergency lighting and alarm systems, stationary engine starting, PV systems and large-scale storage, on-grid and off-grid.

Battery packs in scope are typically above 100 kWh. Packs of 100 kWh or less are covered by GB 40165. Batteries for vehicles and mobile equipment follow their own standards unless they are integrated into a stationary storage system.

#What is tested

Requirements are organised in two levels.

Cells — mechanical and electrical abuse tests such as vibration, shock, penetration and forced discharge, plus thermal runaway.

Battery pack systems — environmental tests such as dropping; electrical protection such as overvoltage and overcurrent charge control, undervoltage discharge control and overheating control; and insulation, short-circuit protection, reverse-connection protection and dielectric strength.

#Thermal runaway and thermal propagation

Two tests carry most of the weight:

• Cell thermal runaway. A fully charged cell is heated until it goes into thermal runaway, to characterise its behaviour.
• Pack thermal propagation. One cell inside the pack is forced into thermal runaway. The pack system must stop the event from spreading into a fire: no external flame and no rupture of the enclosure. Fire or rupture of the triggered cell itself is allowed, because it is the deliberate trigger.

The standard allows a module to replace the full pack for the propagation test, provided the cell layout around the trigger cell matches the pack.

Interpretations differ on the exact number of test items, on observation times, and on whether the 100 kWh boundary is inclusive. Use the standard text, not secondary summaries, when building the test plan.

#What it means for manufacturers

• Design for propagation early. Cell spacing, thermal barriers, venting paths and the battery management system decide the propagation result, and they are hard to change late.
• Choose the representative sample. If a module is used for the propagation test, document why its layout represents the pack.
• Align with export requirements. UL 9540A and IEC 62619 address similar hazards, so a coordinated test plan can feed several markets.

Our partner laboratory network supports energy storage projects with converter and system testing up to 2.5 MW, including grid connection, safety and EMC.