Number of charging cycles for energy storage batteries

What is a battery charging cycle?

A charging cycle comprises a complete charging and discharging process, i.e. charging the battery from 0% to 100% and then discharging it back to 0%. Battery service life: The number of cycles is an indicator of the service life of a battery. The higher the number of cycles, the longer the battery will last before it needs to be replaced.

What is a battery cycle?

The Big Battery at Leighton Buzzard, England, the first grid-scale lithium battery energy storage system in the UK, connected in 2014. Image: S&C Electric Unfortunately, and confusingly, the industry has different definitions for what ‘a cycle’ actually is. In commercial documents, such as warranties, a cycle is calculated via energy throughput.

How is a battery cycle calculated?

In commercial documents, such as warranties, a cycle is calculated via energy throughput. This tallies the energy going in/out of the battery and divides total energy throughput by capacity. Even though this is a relatively simple calculation, it actually only tells you the number of ‘Equivalent Full Cycles’, or EFCs.

What does the number of cycles on a battery mean?

Battery service life: The number of cycles is an indicator of the service life of a battery. The higher the number of cycles, the longer the battery will last before it needs to be replaced. Capacity loss: With each charging and discharging cycle, the battery loses some of its original capacity.

How many cycles does a battery need?

Depending on the application: The number of cycles required depends on the application. For example, traction batteries in electric vehicles require a high number of cycles in order to function reliably for many years.

How many cycles does a lithium ion battery last?

A typical lithium-ion battery, for example, might have a cycle count of 500 to 1,000 cycles before its capacity drops to approximately 80% of its original capacity. After this number of charging cycles, the battery will still function but will no longer be able to store as much energy as it did at the beginning.