Ni MH battery parameters

Ni MH battery parameters

Any nimh battery should be set up with standard parameters. When facing the market, some parameters should be embodied in the product specification. Usually, the Ni MH battery parameters include the following: 

Ⅰ. The core parameters that determining the performance of the nimh battery: 

1. Nominal capacity: the capacity of a battery is determined by the number of active substances, while the content of the active substance is determined by the material and volume used by the battery. Therefore, the larger the size of the battery, the higher the capacity.

2. Nominal voltage: the potential difference between the positive and negative electrodes when the battery is just leaving the factory is the nominal voltage. The nominal voltage of a Ni MH battery is 1.2V. The nominal voltage is determined by the electrode potential of the plate material and the concentration of the internal electrolyte. The output voltage of the cell is changed when the environment temperature, the operating time, the working state and the residual electric quantity are changed.

3, the internal resistance of the battery is determined by the resistance of the plate and the impedance of the ion flow. The resistance of the plate is constant during charging and discharging. The impedance of ion flow will change with the change of electrolyte concentration and the increase or decrease of charged ions.

4. After the Ni MH battery is charged, the active material of the plate has reached saturation state, and the charging voltage will not rise. The voltage is called the termination voltage, and the termination voltage of the Ni MH battery is 1.4V.

5, the discharge termination voltage is the lowest voltage allowed when the Ni MH battery discharge, and continues to discharge at the termination voltage state. The voltage of the battery will drop rapidly at both ends of the battery, forming a deep discharge and over discharge. In this way, the resultant formed on the plate is not easy to recover when it is normally charged, and it will affect the life of the battery.

6, charge discharge current: must have the maximum current regulation. Because the high current will impact the stability of the battery structure.

Ⅱ. Indicator for battery performance:

1, cycle life: once a full charge and discharge process is regarded as a charging cycle of Ni MH battery, the battery's cycle life is formed by repeatedly charging the battery. The charging cycle of Ni MH battery is regulated according to the IEC standard. Normally, the lifetime of Ni MH battery should reach 500 times.

2, specific energy: common standards are: (1), energy / weight is 30~80wh/kg (Watt hour / kilogram); (2), energy / volume is 140~300wh/l (Watt hour / liter).

Ⅲ. Parameters describing physical properties of batteries: 

1. Weight: Ni MH battery is the heaviest in the same type of battery.

2, model: according to the relevant standards named, such as commonly used AAA, AA and so on.

3, outline size: single battery must indicate the diameter and height. The combined battery is usually expressed in three dimensions.

4. External packaging and printing.

The above parameters do not always appear in product descriptions, but some important parameters must be marked, such as the core parameters.