Storage High Temperature Testing in Batteries

In consumer products and product safety testing, particularly within the realm of batteries and chargers, storage high temperature testing (SHTT) plays a crucial role. This type of testing ensures that battery systems can withstand extreme environmental conditions without compromising performance or endangering users.

During SHTT, batteries are subjected to prolonged exposure at elevated temperatures to simulate real-world scenarios where they might be stored in hot environments such as vehicles parked under the sun or warehouses with inadequate cooling. This test is not merely a formality but essential for ensuring product safety and reliability.

The process involves placing fully charged or partially discharged batteries into an environmental chamber, which is then brought to specified temperatures and held there for a defined period. The temperature range typically spans from ambient up to 65°C or higher, depending on the standards being followed (e.g., IEC 62133). It’s important that this testing accurately reflects real-world conditions without overstating potential risks.

Storage high temperature testing helps identify issues such as thermal runaway, where excessive heat causes a rapid increase in internal pressure leading to cell failure. Such failures can result in leakage, fire hazards, or even explosion. By identifying these vulnerabilities early on during development and manufacturing stages, manufacturers can implement corrective measures before products reach market.

The testing procedure includes rigorous monitoring of various parameters including voltage, current, temperature rise rates inside the battery pack, specific energy output (Wh/kg), and internal resistance changes over time. These metrics help determine whether a particular design meets safety requirements specified by relevant standards like UL 1642 or UN Model Regulations.

Proper specimen preparation is critical to ensuring accurate results from SHTT. This includes selecting representative samples that reflect the intended product use, packaging them appropriately for storage within the environmental chamber, and adhering strictly to prescribed protocols regarding charging/discharging prior to testing.

Industry Applications

Industry Sector	Description of Application
Battery Manufacturers	Evaluating the thermal stability and safety features of new battery designs.
Automotive OEMs	Testing batteries intended for electric vehicles (EVs) under extreme conditions to ensure they perform safely throughout their lifecycle.
Energypack Suppliers	Demonstrating the safety and reliability of large-scale storage solutions like EVSE batteries or grid-connected systems.

Why Choose This Test

The decision to conduct storage high temperature testing is driven by several factors. Firstly, it provides critical insights into how batteries behave under conditions that they may encounter during shipping, storage, or even while parked in direct sunlight. Secondly, this test helps ensure compliance with regulatory requirements such as IEC 62133 which mandates certain levels of thermal stability for rechargeable lithium-ion cells.

Moreover, it allows manufacturers to optimize their products by identifying any weaknesses in the design that could lead to safety hazards. For instance, if a particular battery chemistry shows signs of swelling or deformation when subjected to prolonged high temperatures, adjustments can be made accordingly during subsequent iterations. This proactive approach not only enhances product quality but also protects brand reputation and fosters trust among consumers.

Additionally, conducting SHTT allows companies to demonstrate their commitment to safety and sustainability. In today’s competitive market where consumer awareness about environmental impact is growing, demonstrating robust testing protocols can set a company apart from its competitors. It shows that they prioritize both human health and planetary well-being when designing products.

Benefits

Ensures compliance with international safety standards (e.g., IEC 62133).
Identifies potential risks early in the product lifecycle.
Reduces likelihood of recalls due to battery failures or fires.
Promotes safer handling and storage practices by manufacturers.

What temperature ranges are typically used in storage high-temperature tests?

Typical temperature ranges for storage high-temperature testing can vary but generally fall between 45°C and 65°C. These temperatures simulate extreme conditions that batteries might encounter during transportation or long-term storage.

How long do batteries remain at the elevated temperature?

The duration can vary depending on specific requirements but usually ranges from 72 hours to one week. Longer durations are sometimes employed for more rigorous evaluations.

Is this test applicable only to lithium-ion batteries?

While it is commonly used with lithium-ion batteries, SHTT can be applied to other types of rechargeable batteries as well. The methodology may need slight adjustments based on the chemistry and form factor.

What kind of data should I expect from this test?

You can anticipate detailed reports including changes in battery voltage, internal resistance, specific energy output, and temperature profiles. These metrics are crucial for assessing the impact of prolonged exposure to high temperatures.

Does this test require any special equipment?

Yes, specialized environmental chambers capable of maintaining precise temperature control and monitoring capabilities are necessary. Additionally, specific software tools may be required to analyze the collected data accurately.

How does this test differ from accelerated life testing?

While both types of tests involve exposing batteries to harsh conditions, SHTT focuses specifically on storage and the potential for thermal runaway. Accelerated life testing aims at simulating longer-term aging effects through more aggressive cycles.

What standards should I follow?

You should adhere to relevant international standards such as IEC 62133, UL 1642, and UN Model Regulations. These documents provide clear guidelines on how to conduct these tests effectively.

Does this test apply equally well to all types of batteries?

While the core principles remain consistent, adjustments might be needed for different chemistries. For instance, alkaline batteries may not need such high temperatures since they are designed for different applications.