What Does Cycle Life Mean in Lithium Batteries?

Home Page Orbit Academy What Does Cycle Life Mean in Lithium Batteries?

What Does Cycle Life Mean in Lithium Batteries?

What is the purpose of the cycle life information (also known as cycle life) in lithium batteries?
Is cycle life related to battery quality?
How should cycle life data be interpreted?

Cycle life in lithium batteries is extremely important.
It not only shows how many times a battery can be charged and discharged,
but also indicates whether the battery is safe and reliable.

When manufacturers or sellers list the technical specifications of a lithium battery,
they always include a cycle life value.

For example:

  • A battery with 3,500 cycles is priced at 750 USD,

  • Another battery with 4,000 cycles is priced at 1,000 USD.

At first glance, paying 250 USD more for 500 extra cycles may not seem necessary.
However, there are some very important details to pay attention to:

  1. The 3,500-cycle battery priced at 750 USD may specify this value at 80% Depth of Discharge (DoD).

  2. The 4,000-cycle battery priced at 1,000 USD may specify it at 100% DoD.

If the second battery were also tested at 80% DoD,
its actual cycle life could reach 6,000–8,000 cycles.
So, the more expensive battery might actually be more economical in the long run.

When we put price aside,
how does cycle life relate to quality, and why is quality important?

Simply put:
The internal structure and chemistry of lithium cells determine both cycle life and overall safety —which makes understanding these values essential when selecting a battery.

 

 

Between the anode and cathode, there is a separator.
This separator acts like a filter or mesh, allowing lithium ions to pass between the cathode and anode while preventing electrons from crossing directly.

The quality of the separator is one of the most critical factors determining the overall quality of a lithium cell.
If these separators begin to degrade early — which is one of the key differences between short cycle-life and long cycle-life cells — the two plates may become prone to short-circuiting.

This can lead to batteries self-discharging rapidly or, in worse cases, catching fire due to internal short circuits.
If exposed to high charge/discharge currents, the battery can become severely damaged.

At high or very low temperatures, low-quality separators degrade faster and have a shorter lifespan.

On the other hand, the anode (aluminum foil) is coated with lithium iron phosphate (LiFePO₄) material.
During this coating process, it must be evenly applied and completely covered, even at the micron level, because any inconsistency affects the total cell capacity.

Another major factor that determines the cycle life of a cell is its manufacturing technology.
For example, in prismatic LFP cells, the final step is sealing the aluminum case.
This process must be performed using laser welding, ensuring a perfect airtight seal.

The overall battery quality depends on:

  • The grade and thickness of aluminum,

  • The weld quality,

  • The seal quality at pole connections, and

  • The valve quality.

All these components and processes must be flawlessly aligned to achieve long cycle life.

Although many cells look identical from the outside, the true difference lies in the depth of manufacturing quality and raw material standards.
Cycle life is not a digital counter — it reflects how well the cell was designed and built.

In Summary

Batteries with a short cycle life may fail unexpectedly and leave you stranded.
In low-quality batteries, cycle life shortens further over time.

For instance:

  • A battery rated for 8,000 cycles might only reach 2,500 cycles if used lightly (100 cycles per year).

  • A battery rated for 3,500 cycles might fail completely in less than 10 years, or even cause short circuits and damage.

If your application is critical — such as telecommunications, military systems, marine use, UPS, forklifts, or trucks — a battery failure could cause serious damage.
Therefore, always choose high cycle-life lithium batteries with high charge/discharge capacity.

Orbit Lithium Batteries are produced with 6,000 cycles at 95% DoD.
Given their A+ cell capacity and quality, they can reliably achieve 6,000 cycles at 100% DoD.

Even after two years of use, they still retain 100% capacity, confirming their durability.

Their 1C discharge capability demonstrates high cell quality —
and the fact that they maintain normal temperature during 1C discharge shows full compliance with safety standards.

This makes Orbit Lithium Batteries ideal for demanding applications such as telecom systems, military projects, boats, UPS systems, forklifts, and trucks,
ensuring long-lasting and trouble-free performance.

 

 

Date: 30.10.2024

 

Yardım İkonu