What Is a Good Internal Resistance for a Li-ion Battery?
The internal resistance of a Li-ion battery is an important factor to consider when choosing a battery for any electronic device. Internal resistance refers to the resistance that occurs within the battery itself as electrical energy is converted to chemical energy during the charging and discharging processes. A lower internal resistance means that the battery can deliver more power and provide longer runtimes, while a higher internal resistance can cause the battery to lose efficiency and degrade faster. In this article, we will explore what a good internal resistance for a Li-ion battery is and why it is essential to consider when choosing a battery.
What Is Internal Resistance?
Internal resistance is the resistance that occurs within a battery as a result of chemical reactions taking place during the charging and discharging processes. The resistance is caused by the interaction between the electrodes and the electrolyte, which results in a voltage drop within the battery. This voltage drop reduces the amount of electrical energy that can be delivered to the device, resulting in a lower output voltage and reduced performance.
A good internal resistance for a Li-ion battery will depend on several factors, including the intended use of the battery, the design of the device, and the desired performance characteristics. Generally, lower internal resistance is better as it allows for higher output voltage and longer runtimes.
Factors that Affect Internal Resistance
There are several factors that can affect the internal resistance of a Li-ion battery, including:
Chemistry: Different Li-ion battery chemistries can have different internal resistances. For example, Lithium Iron Phosphate (LiFePO4) batteries have lower internal resistance compared to Lithium Cobalt Oxide (LiCoO2) batteries, making them a more efficient choice for high-powered devices.
Temperature: The internal resistance of a Li-ion battery is temperature-dependent. Higher temperatures can cause the resistance to increase, resulting in reduced performance and shortened lifespan.
State of Charge: The internal resistance of a Li-ion battery can also vary depending on its state of charge. As the battery discharges, the resistance tends to increase, resulting in reduced performance.
Manufacturing Quality: The quality of manufacturing can also affect the internal resistance of a Li-ion battery. Higher quality batteries will have tighter tolerances and better consistency, resulting in lower internal resistance and better performance.
What Is a Good Internal Resistance for a Li-ion Battery?
A good internal resistance for a Li-ion battery will depend on the intended use of the battery. For example, a battery designed for high-powered devices will require a lower internal resistance than a battery designed for lower-powered devices. Generally, a good internal resistance for a Li-ion battery will be below 100 milliohms (mΩ) for most applications. However, for high-powered devices, a lower internal resistance of below 50 mΩ may be necessary to achieve optimal performance.
Conclusion
The internal resistance of a Li-ion battery is an important factor to consider when choosing a battery for any electronic device. A good internal resistance will depend on several factors, including the intended use of the battery, the design of the device, and the desired performance characteristics. Generally, a lower internal resistance is better as it allows for higher output voltage and longer runtimes. When selecting a Li-ion battery, consider the chemistry, temperature, state of charge, and manufacturing quality to ensure optimal performance and longevity.
3.7V 1S Lithium Ion 18650 Li-ion Battery Pack with PCB at Top
