Intermittent Use Of Lithium Batteries — How Does It Affect Longevity?

Understanding Depth of Discharge (DOD)

When you use lithium batteries intermittently, it’s essential to understand depth of discharge (DOD), which refers to the percentage of a battery’s total capacity that is used up before recharging. For example, if a 12V 200Ah battery has a DOD of 80%, it means the battery is using 160Ah (80% of 200Ah) of its capacity. Repeatedly discharging lithium batteries to their maximum capacity can accelerate aging and reduce lifespan.

Effects of Intermittent Use on DOD

Intermittent use of lithium batteries can lead to a phenomenon called “calendar aging,” where the battery ages faster due to repeated cycle stress. To mitigate this, it’s recommended to maintain a DOD of 50-60% or less for most lithium-ion batteries. This means that if you have a 12V 200Ah battery, aim to keep the depth of discharge between 100Ah and 120Ah. This can help extend the battery’s lifespan by 10-20%.

Best Practices for Intermittent Use

To maximize the lifespan of lithium batteries used intermittently, follow these best practices:

• Maintain a DOD of 50-60% or less.
• Monitor the battery’s state of charge and keep it between 20% and 80% charged when not in use.
• Avoid deep discharges (above 80% DOD) whenever possible.
• Consider using a battery management system (BMS) to monitor and control the battery’s charge and discharge cycles.
• Store the battery in a cool, dry place when not in use, and avoid letting it sit at 100% charge for extended periods.