How to judge the condition of car battery?

The low temperature in winter is an important factor affecting the state of the car battery, because the battery performance will decline at low temperature, the normal state of health of the battery is not very big, and those who are seriously aging battery is most likely to have problems in the winter. According to past experience, if the battery appears these three phenomena can basically judge its state is not too good.

  1. Low battery voltage

Under normal circumstances when the car battery voltage should be above 12V, if the voltage is lower than this voltage indicates that the power is insufficient or the battery is aging. In addition, the battery voltage should be measured according to the stabilized reading. Because the voltmeter itself consumes a certain amount of power, some of the battery voltage is virtual, and the voltage can barely meet the standard at the beginning of the measurement, but if you put the measuring pen directly on the battery, you will find that the voltage reading will gradually drop, and then stay stable. And the voltage that holds steady is the true voltage of the battery.Comparison table of voltage and quantity of battery

  1. Reduced starting capacity

The car uses lead-acid batteries, which produce an electric current through a chemical reaction inside the battery. At low temperature, the rate of chemical reaction decreases, so low temperature will affect battery performance.At the same time, low temperature will also cause the flow of engine and gearbox oil to decrease, thus increasing the burden of starting, so the starter needs more current when working, and at this time, the battery in poor state is prone to problems.Measure the battery voltage

  1. Idle on headlights, speed fluctuation

The output voltage of the automobile generator is limited to about 14V, and the generator is directly connected to the battery. If the battery voltage is too low and the output voltage of the generator is lowered, the generator's voltage regulator will adjust the excitation current to increase the generating capacity and increase the voltage. And the excitation current increase will increase the generator rotation resistance, resulting in an increase in engine running resistance.Internal structure of lead battery

The battery in good condition has enough power to maintain its own voltage when turning on the headlights, and the voltage drops very little, so the generator excitation current changes very little, and the hindering effect on the engine is not obvious. And the bad state of the battery in idle speed operation voltage although normal, but are virtual, when the light on the battery voltage will be significantly decreased, resulting in the generator output voltage is also greatly pulled down, the voltage regulator will be significantly adjusted excitation current, resulting in a significant increase in the load of the engine resulting in speed fluctuations. So if the speed fluctuates when you idle on the headlights, the state of the battery is not very good.voltage fluctuation

In daily use by these three methods can quickly determine battery state, but should pay attention to some of the car may be due to long time short or long time place lead to battery power without timely supplement, also can appear similar situation, this time don't have to rush to change, should be first to the accumulator, if everything is in order, after filling the electricity so that the battery is running low, No need to replace it.

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