DC internal resistance vs AC internal resistance: which is m

DC internal resistance vs AC internal resistance: which is more important?

 

With the advancement of technology, batteries play an increasingly important role in our lives. From mobile phones, laptops to electric cars, batteries are everywhere. However, do you know how the performance of a battery is affected by its internal resistance? As an expert with many years of experience in the field of electrical engineering, I will give you an in-depth analysis of the impact of battery internal resistance on its performance in this article.

 

Battery internal resistance, in simple terms, is the resistance encountered when current passes through the battery. It includes two parts: DC internal resistance and AC internal resistance. Both types of internal resistance will affect the performance of the battery, but in different ways.

 

Let's look at DC internal resistance. Also known as ohmic internal resistance, it is the resistance encountered by electrons when they move through the internal material of the battery during discharge or charging. The size of this resistance directly affects the voltage output of the battery. When current passes through the battery, due to the existence of internal resistance, part of the electrical energy will be converted into heat energy, which is what we often call "voltage drop". Therefore, the smaller the DC internal resistance of the battery, the higher its discharge efficiency and the better the battery performance. On the contrary, if the DC internal resistance of the battery is large, there will be greater energy loss during the discharge process, thereby reducing the performance of the battery.

Next, let's look at the AC internal resistance. AC internal resistance refers to the resistance of the battery under the action of AC, which mainly reflects the chemical reaction process inside the battery. This process usually involves the adsorption and desorption of charges on the electrode surface, and the migration of ions in the electrolyte. The size of the AC internal resistance directly affects the frequency characteristics and dynamic response of the battery. If the AC internal resistance of the battery is small, then at high frequencies, the battery's discharge capacity will be stronger. On the contrary, if the AC internal resistance of the battery is large, then at high frequencies, the battery's discharge capacity will be weakened.