Author :Iflowpower – Portable Power Station Supplier
How to test UPS battery internal resistance? Whether it is the battery is about to fail, the capacity is insufficient or the battery is filled, it can reflect from its internal resistance. Therefore, it can be measured by the UPS battery, and the working state can be evaluated. The common method of currently measuring the internal resistance of the battery is: (1) Density Density Method Important to estimate the internal resistance of the battery by measuring the density of the UPS battery electrolyte, often used for the internal resistance of the open lead-acid battery, not suitable for sealing lead acid Battery internal resistance measurement.
Application of this method is narrow. (2) Open circuit voltage method is an open circuit voltage method to estimate the battery internal resistance by measuring the end of the battery, and the accuracy is very poor. Even the error conclusion.
Because even if a capacity has changed very small battery. The end voltage can still be very normal under the floating state. (3) DC discharge method DC discharge method is to discharge the battery by instantaneous current.
Measure the instantaneous voltage drop on the battery. Calculate the internal resistance of the battery through ohmic law. Although this method has also been widely used in practice, it also has some shortcomings.
If you use this method to detect the internal resistance of the battery must be in static or offline, online measurement cannot be implemented. And the large current discharge will cause a large harm to the battery, thereby affecting the battery life and life. (4) AC injection method AC method measures the voltage response signal Vo of both ends of the battery by injecting a constant AC current signal IS to the battery, and the phase difference between the battery is measured to determine the internal resistance of the battery.
This method does not need to discharge the battery, you can realize the internal resistance of the battery inside the battery. Therefore, it will not affect the performance of the battery. The method should measure the most AC current signal IS, voltage response signal Vo.
And the phase difference between the voltage and the current.