Lithium ion batteries are widely used in electric vehicles, consumer electronics, energy storage systems and other fields due to their high energy density and excellent cycle performance. However, the performance and life of lithium ion batteries are largely affected by storage conditions. In order to standardize the storage management of lithium ion batteries and ensure the safety and performance of batteries, SAE International issued the standard SAE j35‑2023 lithium ion battery storage best practices (hereinafter referred to as the standard) in 2023. This article will introduce and interpret the core content and key requirements of this standard in detail to help relevant industry personnel better understand and apply the storage operation of lithium ion batteries.

I. Standard background and purpose

lithium ion battery in during the storage process, if it is not properly managed, problems such as capacity attenuation, increased internal resistance and even potential safety hazards will easily occur. Battery storage environment temperature, charging state, storage time and other factors directly affect its subsequent use performance. SAE j35‑2023 aims to provide a scientific and systematic lithium ion battery storage operation guide to help manufacturers, supply chains and end users optimize the battery storage process and reduce battery performance degradation and safety risks.

II. Storage environment requirements

1. Temperature control

the standard emphasizes that storage temperature has a great influence on lithium ion batteries. The ideal storage temperature should be kept between 15°C and 2°C.Between 5°C, avoid high temperature and extreme low temperature environment. High temperature will accelerate the internal chemical reaction of the battery, resulting in capacity attenuation and aging; While too low temperature may lead to electrolyte crystallization, damaging the battery structure. It is recommended to provide temperature monitoring equipment in the storage environment to ensure that the temperature fluctuation does not exceed ± 5°C.

2. Humidity management

high humidity will cause corrosion of battery shell and decomposition of internal electrolyte, while low humidity may lead to aging of battery sealing materials. The standard recommends that the relative humidity of the storage environment be controlled between 30% and 50%, and sudden humidity changes should be avoided. In addition, the storage area should be kept dry and ventilated to prevent condensation.

3. Clean and dustproof

the storage place should be kept clean to prevent dust, corrosive gases and other pollutants from contacting the battery, and to prevent the potential impact of external pollution on the safety of the battery. The standard recommends cleaning the storage environment regularly and adopting sealing measures to reduce the intrusion of harmful components in the air.

III. Battery status management

1. State of charge (SOC) requirements

the charging state of the battery has a significant impact on the storage performance. SAE j3235‑2023 clearly suggests that the lithium ion battery should be adjusted to 40% to 60% of the State of Charge (SOC) before storage. Too high SOC will accelerate the self-discharge and aging of the battery. Too low SOC may cause excessive discharge of the battery, causing irreversible damage.

2. Battery detection and maintenance

during storage, the voltage and temperature of the battery should be checked regularly to ensure that the battery is in a safe state. In the standard, it is recommended to perform a maintenance charge-discharge cycle on the storage battery every 3 to 6 months to restore the battery activity and avoid overdischarge. In addition, the battery should be monitored for abnormal phenomena such as expansion and leakage, and timely measures should be taken.

3. Packaging and fixing

the battery should adopt shockproof and moisture-proof packaging materials during storage to avoid mechanical damage and environmental impact. Battery Thermal management should be considered in packaging design to avoid heat accumulation. At the same time, the battery should be fixed and secure to prevent displacement and collision during transportation or handling.

IV. Safety management measures

1. Fire and explosion-proof design

because lithium ion batteries have potential thermal runaway risks, the storage environment must be equipped with fire fighting facilities and explosion protection measures. Standard requires storageThe area should be equipped with automatic fire extinguishing system and equipped with fire extinguishing equipment suitable for lithium battery fire, such as dry powder fire extinguisher or carbon dioxide fire extinguisher.

2. Security monitoring system

it is recommended to install a battery status monitoring system to track the battery voltage, temperature and environmental parameters in real time, and detect abnormal alarms in time. The storage area shall be restricted to unauthorized personnel to ensure the implementation of safety management specifications.

3. Emergency plan

the standard requires the formulation of detailed safety emergency plans, including the handling process of fire, leakage and other emergencies. Relevant personnel should receive safety training and be familiar with emergency operations to reduce accident losses.

V. Storage cycle and life management

the longer the storage time of lithium ion battery is, the more obvious the performance attenuation is. SAE j35‑2023 suggests that the storage period should be set reasonably according to the battery type and storage conditions. For example, under normal circumstances, the battery can be safely stored for more than 12 months in a suitable environment, but it should be checked and maintained regularly.

The standard also points out that a complete battery file should be established during the storage process to record each detection, maintenance and environmental parameter changes, providing data support for subsequent battery performance evaluation and life prediction.

VI. Suggestions on standard implementation and application

in order to meet the requirements of SAE j35-2023, relevant enterprises should start from the following aspects:

• improve storage facilities: Invest in temperature and humidity control, ventilation, fire prevention and monitoring systems to ensure that the storage environment meets the standards.
• Formulate operating procedures: formulate a detailed battery storage operation manual based on the standard content, covering the adjustment of charging status, inspection and maintenance, safety management and other links.
• Personnel training: strengthen the training of storage management personnel, improve safety awareness and operation skills, and prevent accidents caused by human error.
• Data management: establish a battery storage database, record the battery status and environmental changes in real time, and support quality tracking and risk control.

SAE j35‑2023 lithium ion battery storage Best Practices provides scientific and systematic guidance for the storage management of lithium ion batteries, covering environmental conditions, battery status, security measures and maintenance cycle and other key aspects. Strict compliance with this standard can not only prolong the service life of lithium ion batteries and reduce performance attenuation, but also effectively prevent potential safety hazards during storage.