Semco university – All about the Lithium-Ion Batteries


Unlocking the Mysteries of Battery Capacity and Magnification

Batteries have become an integral part of our daily lives, powering everything from our smartphones to electric vehicles. Yet, understanding their capacity and magnification can often seem like deciphering a cryptic code.

In this article, we’ll demystify these crucial battery specifications.

Defining Capacity

In the world of batteries, capacity is a fundamental parameter that determines how much energy a battery can store and release. It’s like the fuel tank in your car; the larger the tank, the more miles you can travel before refueling.

Battery capacity is typically defined in milliampere-hours (mAh) or ampere-hours (Ah). For lithium batteries, the standard industry definition states that the capacity is measured under specific conditions:

Temperature: The battery’s temperature must be maintained at 25 degrees Celsius.

Voltage Range: The battery is discharged from 4.20 volts (fully charged) to 2.75 volts (discharged).

Discharge Rate: The battery is discharged at a constant current of 0.2C, which means it takes about 5 hours to fully discharge.

Why these specific conditions?

To ensure consistent testing, we first standardize the temperature. Next, discharging the battery from 4.20V to 2.75V indicates full capacity usage. We choose a discharge rate of 0.2C to minimize heat generation and maintain accurate measurement. This rate also prevents voltage drops that could impact accuracy.

By understanding this precise definition, we ensure comparable and reliable battery capacities across the industry.

Unveiling Magnification (C Rating)

When it comes to batteries, capacity and magnification (or “C rating”) are key factors to consider. Capacity refers to the total energy a battery can store, while magnification tells us how quickly it can release that energy.

The magnification, represented by the C number, is a unitless value that shows how many times the battery can discharge its capacity in one hour. For instance, a battery labeled as “5000mAh 30C” means it has a capacity of 5000mAh and a magnification of 30 times. This indicates it can continuously discharge at a rate of 30 times its capacity, or 150 amperes (A), for one hour.

Similarly, a battery marked as “25C 2200mAh” has a capacity of 2200mAh and a magnification of 25 times. This means it can discharge at 55A for an hour.

It’s important to note that the C rating already accounts for continuous discharge capability. Claims of instant discharge rates higher than the specified C rating are misleading and not used in the industry for evaluating battery performance.


When selecting a battery for your device or application, it is crucial to grasp the concepts of capacity and magnification. Capacity indicates the amount of energy the battery can store, while the C rating indicates its ability to deliver that energy rapidly. Equipped with this understanding, you can confidently make informed choices regarding your battery requirements, guaranteeing both optimal performance and safety.

For More Updates Follow Us


Leave a Comment

Your email address will not be published. Required fields are marked *