The internal resistance (IR) of a battery is defined as the opposition to the flow of current within the battery. There are two basic components that impact the internal resistance of a battery; they are electronic resistance and ionic resistance. The electronic resistance plus the ionic resistance will be referred to as the
Batteries will always have some resistance. Though the internal resistance may be or appear low, around 0.1Ω for an AA alkaline battery, and about 1Ω to 2Ω for a 9-volt alkaline battery, it can cause a noticeable drop in output voltage if a low-resistance load is attached to it.
The pulse load test is another method for measuring battery internal resistance. It involves applying a short-duration, high-current pulse to the battery and measuring the voltage response. The internal resistance can be calculated from the voltage drop during the pulse. 1.
Ideally, a battery should have 0Ω internal resistance. So during battery operation, all the voltage will be dropped across the element that the battery is powering instead of the battery dropping voltage across itself. According to voltage division, voltage drops across the element with the higher impedance.
Consider a standard AA alkaline cell. When fresh, it might exhibit an internal resistance of about 0.150 Ω. However, as the battery ages or is subjected to adverse conditions, this value can rise to 0.273 Ω or even higher. This change in internal resistance can significantly affect the battery’s performance.
To illustrate this, consider a simple experiment with a AA cell. When connected to a 4 Ω resistor, the voltage across the battery terminals might drop from its VOC of 1.5V to around 1.45V. This drop is due to the battery’s internal resistance. Quote: “The internal resistance of a battery is like the resistance of a water pipe.
The primary responsibility of internal resistance is to determine the runtime of a battery. The most urgent requirement of a car battery is for it to have low internal resistance. If your battery internal resistance reads with high ohms, it means …