Measurement Method of Internal Resistance of Panasonic Battery
In order to better use Panasonic batteries, we need to understand the measurement method of the internal resistance of Panasonic batteries first, then let Xiaobian introduce it in detail for you!
If the internal resistance of Panasonic battery fails or the capacity is insufficient, it may cause a major accident, so it is necessary to monitor all the working parameters of the battery online. Panasonic batteries are used as standby power supply for power system outage. It has been widely used in industrial production, transportation, communications and other work. One of the first signs of Panasonic's battery condition is its internal resistance.
Whether Panasonic batteries are about to fail, lack of capacity or improper charging and discharging of batteries can be reflected in the change of their internal resistance. Therefore, the internal resistance of Panasonic battery can be tested to evaluate its performance. Nowadays, the common methods for measuring the internal resistance of Panasonic batteries are as follows:
(1) DC Discharge Method
DC discharge method is to measure the instantaneous voltage drop on Panasonic batteries by discharging the batteries with large current in a short time. The internal resistance of Panasonic batteries is calculated by Ohm's law. Although this method has been widely used in practice, it also has some shortcomings. If this method is used to check the internal resistance of Panasonic batteries, it is necessary to carry out static or offline conditions, and online measurement can not be completed. Moreover, high current discharge will cause serious damage to Panasonic batteries, and then affect the maximum capacity and life of batteries.
(2) Open-circuit voltage method
Because even a Panasonic battery whose capacity has now changed to a very small size, its terminal voltage may still behave normally in the case of floating charge. The open-circuit voltage method estimates the internal resistance of batteries by measuring the end plate of batteries, with poor accuracy, and even draws erroneous conclusions.
(3) Density method
Density method is mainly used to calculate the internal resistance of open lead-acid batteries by measuring the density of electrolyte. It is not suitable for the measurement of internal resistance of sealed lead-acid batteries. The applicability of this method is limited.
(4) AC Writing Method
By writing a stable AC current signal Is into the battery, the voltage response signal VO at both ends of Panasonic battery is measured, and the phase difference between the two signals is determined by the impedance formula to determine the internal resistance R of the battery. This method needs to measure the most AC current signal is, the voltage response signal Vo. and the phase difference between voltage and current. This method does not need to discharge batteries, and can complete the safe on-line inspection of internal resistance of batteries. Therefore, it will not affect the function of Panasonic batteries.