Briefly describe the internal resistance measurement method of lithium ion battery

著者：Iflowpower – Portable Power Station ပေးသွင်းသူ

According to the physical formula R = U / I, the test device allows the lithium battery to force the lithium battery to force through a large constant DC current (currently using a large current of 40A to 80A), measurement at this time. The voltage across the lithium battery and calculates the current lithium battery in the formula. Ho nepahala ha mokhoa ona oa ho lekanya ho phahame ebile ho laoloa.

Phoso ea ho nepahala ha tekanyo e ka laoloa ka hare ho 0.1%. However, this method has a significant shortcomings: (1) can only measure a large-capacity lithium battery or a lithium battery, small-capacity lithium battery cannot be loaded with a large current of 40A to 80A within 2 to 3 seconds; (2) When the battery passes the large current, the electrode inside the lithium battery will cause polarization, resulting in polarized internal resistance.

Therefore, the measurement time must be very short, otherwise the measured internal resistance value is large; (3) large current passing through a lithium battery has a certain damage to the electrodes inside the lithium battery. AC pressure drop internal resistance method is actually equivalent to an active resistance because the lithium battery is actually equivalent to a fixed frequency and fixed current to the lithium battery (currently using 1 kHz frequency, 50mA small current), and then samples its voltage After rectification, filtered, the internal resistance value of the lithium battery is calculated by the op amp circuit after a series of processing, etc. The lithium battery measurement time of the AC pressure dropped internal resistance method is extremely short, generally in 100 milliseconds.

Ho nepahala hona ha mokhoa ona oa ho lekanya ho boetse ho molemo, &39;me phoso ea ho nepahala ha tekanyo hangata e pakeng tsa 1% le 2%. The advantages and disadvantages of this method: (1) Use an alternating internal resistance measurement method to measure almost all lithium batteries, including small-capacity lithium batteries. Notebook lithium battery cell internal resistance is generally in this way.

(2) Ho nepahala ha tekanyo ea mokhoa oa ho lekanya khatello ea AC ho ka &39;na ha angoa ke maqhubu a ripple, hape ho ka khoneha ho kena-kenana le harmonic current. This is a test (3) measurement (3) using this method, which does not have too much damage to the lithium battery itself. (4) Ho nepahala ha tekanyo ea mokhoa oa ho lekanya khatello ea khatello ea AC ha e ntle joaloka DC e ntša tekanyo ea ho hanyetsa ka hare.

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