Internal resistance test and maintenance method of primary battery
From the user’s point of view, the purpose of battery detection is to determine the battery health status (soh) and state of charge (SOC) to determine whether the battery needs to be replaced, while the purpose of battery detection is to determine whether the battery needs to be charged. I think this is the core of battery maintenance testing. For more than ten years, the industry at home and abroad has been trying to find a detection method suitable for users, in the engineering environment, not in the laboratory. At present, the maintenance detection method based on internal resistance test has been widely used at home and abroad.
Here are some of our testing experiences over the years:
1. Correctly understand the standard value of internal resistance.
A battery model, its initial internal resistance is determined, you can use the battery state tester to measure the initial internal resistance, and then paste a label on the battery. “The battery state tester of the battery company corrects the initial internal resistance value according to the battery life, charging state and temperature at the time of test for comparison. When the internal resistance test value is higher than 40% of the initial value, it can be concluded that the battery has been broken or will soon become bad. In fact, the internal resistance of damaged batteries is far more than 40%, which is usually more than twice the original.
2. Correct understanding of inherent capacity, retention capacity and state of charge.
The intrinsic capacity is the maximum energy that a battery can store.
Reserve capacity is the amount of energy a battery can provide under current conditions.
The state of charge refers to how little energy the battery actually receives.
The reduction of intrinsic capacity and insufficient charging of battery will lead to the decrease of reserved capacity.
Holding capacity is a value we really care about.
The assessment of retention capacity is very complex, and retention capacity is actually just a vague concept because people are talking about it.
When the capacity is maintained, it is generally not mentioned to maintain the capacity at a certain discharge rate and a certain temperature, but different discharge rates and a certain temperature holding capacity are different, but it doesn’t matter. We can roughly judge the charging state depending on the terminal voltage, and then calculate the special battery holding capacity at room temperature according to the change of the fixed capacity.
The ambient temperature of substation and communication base station is close to 25 ° and the evaluation value of charging state is close to 100% under floating charging state. look out. I’m talking about the starting voltage, not the floating charging voltage measured online.