Lithium ion cells and batteries used in portable medical electrical equipment—Safety technical specification

Standard Overview

SJ/T 12274-2026 'Safety Technical Specifications for Lithium-ion Batteries and Battery Packs for Portable Medical Electrical Equipment' is an electronic industry standard released by the Ministry of Industry and Information Technology of the People's Republic of China and managed by the China Electronics Standardization Institute. The standard was published on June 1, 2026, and implemented on December 1, 2026. It aims to regulate the safety performance of lithium-ion batteries and battery packs used in portable medical electrical equipment, ensuring they do not pose a danger to patients and users under normal use and reasonably foreseeable misuse or abuse conditions.

Scope of Application

This document applies to lithium-ion batteries and battery packs that support portable medical electrical equipment in achieving their intended purposes, including portable monitoring devices (such as electronic sphygmomanometers, heart rate monitors, pulse oximeters, etc.), portable therapeutic devices (such as nebulizers, electrical stimulation therapy devices, automated external defibrillators, etc.), and portable diagnostic devices (such as portable ultrasound scanners, portable electrocardiographs, etc.). The standard explicitly excludes active implantable medical devices and their dedicated external components, and notes that Class III active medical devices may have higher requirements.

Terms and Definitions

The standard defines 31 key terms, including medical electrical equipment, portable medical electrical equipment, lithium-ion batteries, lithium-ion battery packs, nominal voltage, rated capacity, rated energy, charge limit voltage, discharge termination voltage, etc., laying the foundation for subsequent safety requirements and test methods. These terms clearly define product categories, parameters, and performance indicators, avoiding understanding deviations.

General Safety Requirements

The standard requires that batteries and battery packs remain safe under normal conditions and under reasonably foreseeable misuse, abuse, and fault conditions. Manufacturers must specify safe operating parameters (such as voltage, current, and temperature ranges) in the specification sheet and clearly label the product name, model, rated capacity, rated energy, polarity, manufacturer, production date, or batch number on the product. Battery packs designed for user replacement must also undergo durability testing for labeling to ensure the labels remain clear during normal use. Additionally, safety-critical components (such as PTCs and thermal fuses) must comply with relevant standards.

Test Conditions and Type Tests

The standard specifies detailed test conditions, including an ambient temperature of 20℃±5℃, relative humidity not exceeding 75%, and atmospheric pressure between 86kPa and 106kPa. Parameter measurement tolerances are strict, such as voltage ±0.2%, current ±1%, and temperature ±2℃. Type test requirements stipulate that samples must be products manufactured within 6 months, with at least 3 samples per test item, and pre-treatment (charge/discharge cycles and electrostatic discharge) must be performed. Test items are divided into battery electrical safety tests, battery environmental safety tests, battery pack environmental safety tests, battery pack electrical safety tests, and single-cell voltage protection tests, totaling over 30 items.

Test Methods and Key Criteria

Test methods cover electrical safety, environmental safety, and mechanical safety. For example, in the high-temperature external short-circuit test: after fully charging the battery, place it in an environment of 57℃±4℃ and short-circuit it with an 80mΩ resistor; the battery must not catch fire or explode. Overcharge testing involves charging at a specified voltage, requiring no fire or explosion. Forced discharge involves reverse charging at 1It for 90 minutes, also requiring safety. Environmental tests, such as low pressure (11.6kPa for 6 hours), temperature cycling (-40℃ to 72℃ for 10 cycles), vibration, shock, and drop tests, all require no fire, no explosion, and no leakage. Battery packs also require tests for overvoltage charging, overcurrent charging, undervoltage discharge, overcurrent discharge, temperature protection, external short-circuit, reverse charging, and surface temperature limits; the protection circuit must actuate and send an alarm signal to the host device. Single-cell voltage protection ensures that each cell in a series-connected battery pack has overcharge and over-discharge protection.

Comparative Analysis

Compared with general lithium-ion battery safety standards (such as GB 31241-2022), this document adds more safety requirements tailored to medical scenarios:
- Surface temperature limits are categorized by contact time: 74℃ (<1 second), 56℃ (1-10 seconds), 51℃ (10 seconds-1 minute), and 48℃ (>1 minute), better aligning with the requirements for protecting patient skin in medical electrical equipment.
- Chemical compatibility tests have been added to simulate the impact of cleaning and disinfection processes on battery packs.
- Flame retardancy requirements apply to materials such as housings, PCBs, and wires to prevent flame spread.
- Protection circuits must send alarm signals to the host device, coordinating with the YY 9706.108-2021 alarm system standard.
- Single-cell voltage protection ensures independent protection for each cell within the battery pack, enhancing reliability.

Implementation Recommendations

Battery and battery pack manufacturers should design products in accordance with the standard requirements, ensuring reasonable safe operating parameters, reliable protection circuits, and clear labeling. Manufacturers of complete medical electrical equipment should select battery components compliant with this document and consider battery pack alarm signal interfaces during design. Testing agencies must strictly conduct type tests according to the standard, particularly regarding pre-treatment and sample quantity requirements. Users should follow warning instructions and avoid placing battery packs in hazardous environments such as high temperatures, impacts, or compression.