What is the 18650 battery internal resistance? How to measure 18650 battery internal resistance

ଲେଖକ: ଆଇଫ୍ଲୋପାୱାର - Pārnēsājamas spēkstacijas piegādātājs

18650 lithium-ion battery internal resistance? How to measure 18650 battery internal resistance? The accurate calculation of the 18650 lithium-ion battery is quite complicated, and it will be constantly changing during the battery use. According to relevant experience, the larger the volume of the lithium-ion battery, the larger the internal resistance; vice versa. The 18650 internal resistance is generally between 20-65 milliises, and only the voltage can be measured with a multimeter.

The 18650 lithium-ion battery internal resistance is it? In terms of lithium-ion batteries, the internal resistance of the battery is ohmic internal resistance and polarization internal resistance. The ohmic resistance consists of electrode material, electrolyte, diaphragm resistance, and contact resistance of each part. The polarized internal resistance refers to a resistance caused by polarization when electrochemical reactions, including electrochemically and electrodesystems and resistance caused by concentration polarization.

Power 18650 Lithium Ion Battery Because the discharge current is generally large, the internal block is small, such as Samsung 18650-2200-5C power, internal resistance is less than 35 millio. Ordinary 18650, such as Samsung 18650, internal resistance is generally less than 80 millio, actually doing less than 65 millio. At present, the internal resistance of 18650 lithium-ion batteries is about 12 millis, and generally around 13-15 millio; due to impedance affects the performance of the battery, 50 millio is normal, 50-100 It can be used, but performance begins attenuating, and more than 100 is used in parallel, greater than 200 can not be used.

The 18650 lithium-ion battery is too long, and the internal resistance of the lithium ion battery increases, and the output voltage is lowered. The internal resistance, static internal resistance and operation of the lithium ion battery are often different. In different environments, the temperature varies in different environments.

18650 battery internal resistance How to measure? 18650 Lithium-ion battery To measure capacity and internal resistance to dedicated internal resistance tester, 18650 internal resistance is generally between 20-65 milliit, and uses a multimeter to measure the voltage. ● AC pressure reduction internal resistance measurement Method Because the 18650 lithium ion battery is actually equivalent to an active resistance, we apply a fixed frequency and fixed current to a lithium ion battery (currently using 1 kHz frequency, 50mA small current), and then Its voltage is sampled, and the internal resistance value of the lithium ion battery is calculated by a series of processes such as rectification and filtering. The lithium ion battery measurement time of the AC pressure dropped internal resistance method is extremely short, generally around 100 milliseconds.

This accuracy of this measurement method is also good, and the measurement accuracy error is generally between 1% to 2%. According to the physical formula R = U / I, the test device allows the lithium ion battery to force the lithium ion battery to force through a large constant DC current (currently using a large current of 40A to 80A), measure this in a short period of time (currently from 40A to 80A). The voltage at both ends of the lithium ion battery and calculates the current lithium ion battery internal resistance in accordance with the formula.

The accuracy of this measurement method is high and controlled, and the measurement accuracy error can be controlled within 0.1%. The above is the introduction of 18650 lithium ion battery internal resistance.

The resistance is a lithium ion battery at work, and the current flows through the internal resistance of the battery. In the battery structure design, in addition to the riveting and welding of the battery structure itself, the number, size, location, and the like directly affect the internal resistance of the battery.