Shelf life refers to the duration a lithium-ion battery can be stored without significant degradation. The shelf life of a lithium-ion battery in storage varies depending on the storage conditions. It is influenced by factors such as temperature, state of charge, and the specific chemistry of the battery.
When the temperature range is from 35°C~40°C for LFP, the calendar life is 5-6 years. But over 45°C, the calendar life will be shortened to 1-2 years. Different cathode materials have varying calendar life properties. For example, lithium iron phosphate (LFP) batteries often have a longer calendar life than nickel-rich chemistries.
A: Yes, lithium batteries can expire even when not in use. Lithium batteries will have a shorter lifespan as their contents chemically degrade over time. Always check the expiration date on your batteries and store them in a cool, dry place to extend their shelf life.
For optimal shelf life, store lithium-ion batteries at about 40-50% charge. Storing at full charge situation can accelerate aging while storing completely discharged can cause deep discharge and damage the cell risk. Lithium-ion battery manufacturers often charge their battery packs to approximately 60% state of charge (SoC) before shipping.
A battery’s shelf life is indeed determined by the manufacturer based on some factors, including battery chemistry, construction, and storage conditions. The date printed on the battery often corresponds to the production date or manufactured date.
A higher cycle life indicates better durability and longevity of the battery. The cycle life of a lithium-ion battery is often influenced by the depth of discharge (DoD), and deep discharges can have implications on the overall longevity of the battery.