Battery Cell Insulation Tester Model 11210

Chroma 11210 battery cell insulation tester is specially designed to detect leakage current (LC) or insulation resistance (IR) anomalies in lithium battery cells, and can also measure solid-state capacitors, multilayer ceramic capacitors (MLCC), high-voltage electrolytic capacitors and insulating materials. In addition to the standard LC/IR measurement, the tester is also designed to detect and analyze the strong Partial Discharge (PD) or Flashover in the insulator during the high voltage measurement process (hereinafter referred to as the "PD Detection Function"), which helps to detect whether the effective insulation distance is sufficient to avoid potential defects of the dry cell of the lithium-ion batteries before the electrolyte filling. This function can help detect whether the effective insulation distance of the lithium-ion battery dry cell is sufficient before the electrolyte is filled, so as to avoid potential defective products from entering the next production stage or reaching the end market. Compared to traditional insulation testing, the 11210 elevates the safety of lithium-ion battery-powered electrical and electronic products and electric vehicles, as well as the quality of insulation materials, to a new level.

The Chroma 11210 uses a special circuit design to provide PD detection, monitoring the entire test process to see if any abnormal electrical flashover has occurred in the core due to abnormal localized discharges and quantifying it as a visual level and recording the waveform at the same time. After the test potential is reached, the leakage current or insulation resistance value is also measured during the test time to determine the abnormality, just like the general voltage or insulation tester. +The +Flash function provides two stages of intermittent high and low voltages to test the withstand voltage characteristics of the object to be tested at high voltage and the leakage current performance at low voltage, independently determining the size of the leakage current and the PD detection function, which can be effectively applied to a variety of energy storage components.

Chroma 11210's high level of charging current and fast measurement circuits, the overall test speed is greatly improved, the insulation test of general capacitance to be tested can be subdivided into four procedures: charging → determination delay → measurement → discharge, and the fastest in 20ms automatically perform a complete test in sequence, significantly improving the efficiency of the production line. In terms of leakage current measurement, it can be subdivided into 7 levels from minimum 1pA to maximum 20mA to achieve accurate LC/IR measurement. In addition, the auto-range function automatically switches to the optimal level for measurement, saving the user's time and ensuring the accuracy of the measurement.

The contact check has a decisive impact on the reliability of insulation test, during the whole measurement process, "no contact" is also likely to be judged as a good product, this misjudgment will lead to defective products into the market, if the insulation resistance of the object to be tested is very high, this misjudgment will be even more obvious; so in general, the insulation test process must be carried out contact check. The Chroma 11210 utilizes a high level of circuitry to perform a complete contact check within 5ms, and can be selected to perform before, after, or both before and after measurement.

• Lithium Battery Safety Topics
• Strong partial discharge (P.D.) / electrical flashover detection and measurement function
• +Instantaneous High Voltage Test (+Flash Test) Function
• Daily inspection of PD functions

 

 

 Lithium Battery Safety Topics

There are many different scenarios of short circuits within lithium batteries, one of the most serious being a short circuit from the aluminum metal of the positive electrode to the coated material of the negative electrode. When such a short circuit occurs, a large amount of heat is generated in a very small localized space, leading to a fire or explosion! Battery fires and explosions like this are the main cause of several automobile combustion incidents in the past decade. [Figure 1]

▲ [Fig. 1] Car burning due to battery fire and explosion

Lithium battery (LIB) fire or explosion caused by the disaster has been in recent years for the users of serious concerns about the issue, with the continuous evolution of technology, lithium battery energy density has also continued to improve the safety of lithium batteries further evolved into a potential crisis in the lives of users! In order to completely eliminate such a potential crisis, the root cause of lithium battery fire and explosion must be found, and products with potential crisis must be screened out before leaving the factory; research reports show that the short circuit between the aluminum metal of the positive electrode (AL) and the negative electrode's coating material (Anode) is the root cause of the fire and explosion [Fig. 2], and the burrs on the aluminum metal of the positive electrode or the impurity particles in the insulating layer is the main cause of this internal short circuit [Fig. 3], which is the main cause of the internal short circuit [Fig. 5]. [Figure 3].

▲ [Fig. 2] Temperature climb curves caused by internal short-circuiting of four different Li-ion batteries

▲ [Fig. 3] A burr protruding from the aluminum metal of the positive electrode in a lithium battery may touch the material coated on the negative electrode and cause a fire or explosion.

Research reports show that the negative electrode coated material (usually graphite) will expand slightly during each charging process, and after multiple charging, the expansion leads to an increase in thickness of up to 24% resulting in a shortening of the distance between the positive and negative electrodes [Figure 4], resulting in the original electrodes due to electrode burrs or metal foreign matter mixing in the electrodes to make the effective distance is shorter than it should be designed, which can easily evolve into an internal short-circuit. Usually, Li-ion batteries undergo several charge/discharge cycles in the production line. For example, if there are two defective batteries, each with a burr of different lengths on its aluminum electrode plate [case 1 & case 2 in Fig. 5], case 1 is very likely to have an internal short-circuit problem during the second charging cycle on the production line, while case 2 will unfortunately happen to the consumer.

▲ [Fig. 4] In the actual test, it was found that even after only 10 charge/discharge cycles, the graphite material in the negative electrode may expand more than 24%.

▲ [Fig. 5] Two defective batteries, each with a burr of different lengths on their aluminum electrode plates, will generally erupt with internal short circuits at different points in time