Voltage (V) = Current (I) x Resistance (R) Charge quantity (Q) = current (I) x time (T) Power (P) = V x I = Energy (W) = P x T = Q x V Any object has an impedance. Adding a potential difference across the impedance will cause the charge to flow through the impedance. The larger the impedance, the smaller the amount of charge flowing per unit time (one second), and the smaller the impedance, the unit time. The more the amount of charge flowing, the more the amount of charge flowing per unit time increases as the potential difference increases, and the smaller the amount of charge per unit time is when the potential difference is decreased. This potential difference is called voltage. (V), the unit is volt (V), the amount of charge flowing per unit time is called current (I), the unit is ampere (A), the impedance is called resistance (R), the unit is ohm (). current (I) The greater the intensity, the more the number of charges flowing per unit time, the total number of charges flowing through the resistor in T seconds is I x T, and the noun used to describe the amount of charge is the amount of charge (Q). ), commonly known as power, in Coulomb (Q). The power consumed by the resistor (P) is I x V, in watts (W). The greater the power consumption, the more power is consumed. The energy consumed (W) is P. x T, the unit is Joule (J), the longer the time, the more energy is consumed, and the greater the power consumption during the same time, the greater the energy consumption. For example: When a 1.5V dry battery is connected to a 0.5 bulb, the current consumption is 3A, the power consumption is 4.5W, and a total of 30 coulombs of charge is consumed in 10 seconds, which consumes 45 joules of energy. There are many types of material batteries. In a chemical battery, a battery that is thrown away when it is not used up is called a primary battery. A battery that can be used for multiple times is called a secondary battery, and a nickel-cadmium battery belongs to a secondary battery. A kind of medium-alkaline battery . Nickel-cadmium battery uses nickel oxyhydroxide in the anode, cadmium compound as active material in the cathode, and alkaline aqueous solution such as potassium hydroxide in the electrolyte. When charging the nickel-cadmium battery When nickel hydroxide is generated on the anode and metal cadmium is formed on the cathode, a potential difference is formed between the two electrodes. When the anode and cathode of the nickel-cadmium battery are externally discharged, a negatively charged electron is generated at the cathode end. The external load flows to the anode, thus providing energy for external load consumption. Overcharge During the charging process, the voltage of the battery gradually increases with the increase of the stored power. When the stored capacity of the battery reaches the level of the saturated electrode material, the electrolyte will be electrolyzed and the oxygen is generated at the anode. Hydrogen is generated, which causes internal pressure to rise inside the sealed battery, causing damage to the internal structure of the battery. This phenomenon is called overcharging. In order to avoid damage to the overcharged battery, the capacity of the cathode is usually made larger than the anode capacity, so that when overcharged, the anode first saturates and generates oxygen, while the cathode is not saturated without generating hydrogen, and the oxygen generated by the anode diffuses. After the cathode, it will react with the metal cadmium generated by charging to absorb oxygen, and the speed of this reaction is balanced with the speed of metal cadmium generation, so the pressure rise of the battery can be effectively avoided. However, if the charging current is too large (use fast charge) When it is out of balance, the internal pressure of the battery will push the safety valve of the battery away, and hydrogen and oxygen will leak to the outside of the battery until the pressure is lowered. The safety valve closes the battery and then seals again. But the gas leak has caused the internal Reduced chemical materials, resulting in shortened battery life. Change in charging voltage When the battery is overcharged, the oxygen generated by the anode reacts with the cathode to generate heat, so that the temperature of the battery will rise. The outer casing is hot. The higher the temperature, the lower the charging voltage of the battery, so the battery voltage will continue to rise during charging. Until overcharge, the battery temperature will suddenly rise rapidly, and the voltage will no longer rise and turn from the peak. Q When a nickel-cadmium battery is discharged under standard discharge conditions, the voltage will gradually drop until the voltage is almost discharged, and the voltage will drop drastically. This voltage value is called the nominal voltage. The nominal voltage of a typical nickel-cadmium battery. It is 1.2V, which is the same as the 1.5V marked on the general dry battery. It is marked on the battery case. As long as the voltage of the nickel-cadmium battery is at least 1.2V above the nominal voltage, the more the stored electricity, the higher the voltage. high. Discharge termination voltage When the battery is discharged, its voltage will gradually decrease as the battery power decreases. When the voltage drops to the required level, it will not continue to discharge, which is called discharge termination, and this voltage level is called discharge termination. Voltage. Generally, the manufacturer's recommended discharge termination voltage is about 0.9V ~ 1.1V. When the voltage is discharged to this level, the power is almost discharged. This condition is called complete discharge. The nickel-cadmium battery has been completely discharged and will not be removed. Load and let it continue to discharge, then it becomes over-discharge, the voltage will drop rapidly until 0V. If the voltage has not dropped to about 0V to terminate the discharge, the battery voltage will automatically rise back to the nominal voltage of 1.2V. multi speaker, bluetooth speaker, wireless speaker, radio, camping light, solar speaker, hand crank radio speaker camping light, SOS solar DAB radio, NOAA emergency radio speaker bluetooth speaker, wireless speaker, radio, camping light Shenzhen Ewong Technology CO.LTD , https://www.ewongteches.com
Rechargeable battery knowledge highlights
First, let's introduce a few simple basic electrical formulas, and hope that readers without an electronic background can have a few concepts about several physical phenomena.