Temperature and weather conditions can profoundly impact the performance, lifespan, and safety of heated batteries, particularly those used in clothing. Here’s a detailed look at how these factors affect heated batteries:

Effects of Cold Temperatures

1. Reduced Performance

• Description: Cold conditions (below 15°C or 59°F) slow down the chemical reactions within lithium-ion batteries, leading to decreased power output and capacity. This results in shorter runtimes for heated clothing and devices, as the battery struggles to deliver sufficient power[1][2].

2. Increased Internal Resistance

• Description: In cold weather, the internal resistance of batteries increases, making it more challenging for them to charge and discharge effectively. This can cause devices to shut down unexpectedly or exhibit diminished performance in extreme cold[2][3].

3. Potential for Damage

• Description: Extremely low temperatures can cause the electrolyte in lithium batteries to freeze, potentially leading to permanent damage. This not only reduces the battery’s overall lifespan but can also impact safety[3][4].

Effects of High Temperatures

1. Increased Capacity

• Description: Higher temperatures (up to a certain limit) can temporarily enhance battery performance and storage capacity. For example, temperatures rising from 25°C to 45°C (77°F to 113°F) can lead to a 20% increase in maximum storage capacity[4][5].

2. Accelerated Aging

• Description: Prolonged exposure to high temperatures (above 35°C or 95°F) accelerates the chemical reactions that degrade the battery. This significantly shortens the battery’s lifespan, with degradation rates potentially doubling at higher temperatures[5][6].

3. Risk of Thermal Runaway

• Description: High temperatures can trigger thermal runaway, a dangerous condition where increased heat leads to further reactions, potentially causing fires or explosions. This risk is particularly high when temperatures exceed 60°C (140°F)[6][7].

4. Performance Issues

• Description: While batteries may initially perform better in heat, the long-term effects include decreased efficiency and increased risk of failure due to accelerated aging processes[5][6].

General Recommendations

1. Optimal Temperature Range

• Description: Lithium batteries operate best between 15°C and 35°C (59°F to 95°F). Keeping batteries within this range is crucial for maximizing both performance and lifespan[7][8].

2. Storage Conditions

• Description: When not in use, batteries should be stored in cool, dry conditions, ideally at temperatures between -20°C and 25°C (-4°F to 77°F). This helps minimize self-discharge and slows the aging process[7][8].

3. Monitoring and Management

• Description: Implementing temperature monitoring systems can help prevent exposure to extreme conditions, ensuring the safety and longevity of heated batteries in clothing and other applications[6][7].

By understanding these effects and taking appropriate measures, users can optimize the performance and safety of their heated batteries across varying weather conditions.