The battery can not store AC voltage because it is not possible to reverse the battery terminals after a half-wave of the alternating voltage waveform. In this article, we will understand how the battery charges and stores the energy.
The battery has two terminals- an anode and a cathode. The anode of the battery is the positive terminal and the cathode of the battery is the negative terminal. When the battery positive terminal is connected to the positive terminal of the power source and the battery negative terminal to the negative terminal of the power source, the battery draws the current from the source and it stores the electrical energy.
The storage of electrical energy in the battery takes place through the energy conversion process from electrical to the chemical. During discharging of the battery, the stored energy in the battery converts from chemical to electrical energy.
Now, it is clear that the battery charges only when the battery terminals anode and cathode are connected to the positive and negative supply of the voltage source respectively. What happens if the battery anode has its connection to the negative of the voltage source, and the battery cathode has its connection to the positive of the voltage source.
In this condition, does the battery charge? No, the battery can not charge in this condition. This is what exactly happens when we feed AC voltage for charging the battery.
The alternating voltage changes its polarity after each half cycle. The total time of the AC waveform is 20 milliseconds. The polarity of the AC waveform changes after every 10 milliseconds.
The battery when connected to the AC voltage source receives a positive half cycle for 10 milliseconds and battery charges. However, after a lapse of 10 milliseconds, the polarity of voltage changes, and the battery can not charge during the negative half cycle of the AC waveform.
During a 0 to 180-degree time period, the battery receives the positive voltage at the anode and the negative voltage at its cathode. In this condition, the battery charges.
During the 180 to 360-degree time period, the battery receives the negative voltage at the anode and the positive voltage at its cathode. In this condition, the battery does not charge. Here, during the negative half cycle, the battery sees the source as a load, and the battery discharges during this period. Thus, the net charges stored in the battery become zero when the battery receives an AC supply for its charging.
From the above discussion, it is very clear that the battery can not store AC voltage.
