What are the important characteristics of Ni-MH batteries?

There are six important characteristics of nickel-metal hydride batteries: charging and discharging characteristics that show working characteristics, self-discharge characteristics and long-term storage characteristics that show storage characteristics, and comprehensive cycle life characteristics and safety characteristics. They are all determined by the structure of the battery, manifested in the environment, and their distinctive feature is that they are greatly affected by temperature and current. 1. Charging characteristics: When the charging current of the Ni-MH battery increases and/or the charging temperature decreases, the battery charging voltage will increase. Generally, a constant current charge of not more than 1C is used at an ambient temperature between 0°C and 40°C, and a higher charging efficiency can be obtained by charging between 10°C and 30°C. If the battery is often charged in a high temperature or low temperature environment, it will cause the performance of the power lithium-ion battery to decrease. For fast charging above 0.3C, charging control measures are indispensable. Repeated overcharging will also reduce the performance of the battery. Therefore, protection measures for high and low temperature and high current charging must be in place. 2. Discharge characteristics: The discharge platform of Ni-MH battery is 1.2V. The higher the current, the lower the temperature, and the battery discharge voltage and discharge efficiency will decrease. The maximum continuous discharge current of the battery is 3C. The discharge cut-off voltage of the battery is generally set to 0.9V, and the IEC standard charge-discharge mode is set to 1.0V, because a stable current can generally be supplied below 1.0V, and a slightly smaller current can be supplied below 0.9V, so , The discharge cut-off voltage of nickel-hydrogen battery can be regarded as a voltage range of 0.9V~1.0V, and some batteries can be subscripted to 0.8V. Under normal circumstances, if the cut-off voltage is set too high, the battery capacity cannot be fully utilized, otherwise, it is easy to cause the battery to over discharge. 3. Self-discharge characteristic: refers to the phenomenon of capacity loss when the battery is fully charged and stored in an open circuit. The self-discharge characteristic is mainly affected by the ambient temperature. The higher the temperature, the greater the capacity loss after the battery is stored. 4. Long-term storage characteristics: It mainly refers to the power recovery ability of the Ni-MH battery. When used after a long period of storage (such as one year), the capacity of the battery may be smaller than the capacity before storage, but after several charge and discharge cycles, the battery can return to the capacity before storage. 5. Cycle life characteristics: The cycle life of Ni-MH batteries is affected by the charging and discharging system, temperature and method of use. When charging and discharging in accordance with the IEC standard, a complete charge and discharge is the charge cycle of a nickel-hydrogen battery, and multiple charge cycles constitute the cycle life. The charge-discharge cycle of a nickel-hydrogen battery can exceed 500 times. 6. Safety: The safety performance of nickel-hydrogen battery is better in battery design. This is certainly related to the material and material used, but also has an inseparable relationship with its structure. During use, if the battery's internal pressure increases due to improper use of the battery, which causes overcharge, over-discharge, or short circuit, a recoverable safety valve will open, which can reduce the internal pressure and prevent The purpose of the battery explosion. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What are the driving factors for the battery energy storage market?