Battery maintenance and use strategy

Type of battery:

The battery used in a general car is a lead-acid battery. There are two types of common lead-acid batteries, one is a water-added lead-acid battery, and the other is a maintenance-free lead-acid battery.

Water-added lead-acid battery: The plate of an ordinary battery is composed of an oxide of lead and lead, and the electrolyte is an aqueous solution of sulfuric acid. Its main advantage is that the voltage is stable and the price is cheap; the disadvantage is that the specific energy is low (that is, the energy stored per kilogram of battery), the service life is short, and the daily maintenance is frequent.

Maintenance-free lead-acid battery: Maintenance-free battery due to its structural advantages, the consumption of electrolyte is very small, and it is basically unnecessary to supplement distilled water during the service life. It also has the characteristics of shock resistance, high temperature resistance, small size and small self-discharge. The service life is generally twice that of a normal battery. There are two types of maintenance-free batteries on the market: the first one requires no maintenance (addition of replenishing liquid) during the one-time application of the electrolyte at the time of purchase; the other is that the battery itself has been charged with electrolyte and sealed off at the factory. The user can't add supplemental liquid at all.

Battery maintenance method:

After using the battery for the car for more than 2 years, the capacity and discharge capacity will decrease. General vehicle battery life will not exceed 4 years. Of course, a well-maintained battery will last longer. Let's take a look at the maintenance methods for water-added lead-acid batteries and maintenance-free lead-acid batteries.

Water-added lead-acid battery: focus on battery liquid level and battery liquid density.

The battery liquid of a lead-acid battery is a mixture of sulfuric acid and distilled water. When the battery is discharged, the water will become more and the sulfuric acid will decrease, which will result in a decrease in the density of the battery. When charging, on the contrary, the water will become less and the sulfuric acid will increase. The battery fluid concentration reflects the ratio of water to sulfuric acid in the battery fluid. The normal electrolyte density is 1.28 (summer) / 1.29-1.30 (winter) (in grams per cubic centimeter).

As the owner, we should check the battery level regularly. When the battery fluid is insufficient, add distilled water to the appropriate level. After adding distilled water to the battery, we should check the battery liquid density and keep the battery liquid density within a reasonable range.

Maintenance-free lead-acid battery: check the magic eye regularly and keep the battery fully charged

Since the maintenance-free battery has no water hole and battery liquid level scale. We need to judge the state of the battery through the "magic eye" on the battery. The magic eye is green, indicating that the battery is normal, charging is sufficient; the magic eye is black to indicate that it needs to be charged; the magic eye is white to indicate that the battery needs to be replaced.

The discharge capability needs to be detected using a dedicated battery tester.

We generally use a voltmeter to check the battery voltage. Although we can detect the voltage value of the battery, we can't check the battery's load capacity. In order to check the actual condition of the battery, we should use a dedicated battery tester to check the battery's discharge capacity and load capacity.

Weak current cannot be ignored:

After the car is locked, the vehicle anti-theft system starts to work, and it will get a weak current from the battery, so if the car is not used for a long time, the battery will be short of electricity. If the vehicle is found to be stationary for a short period of time, in addition to checking the battery condition, it is also necessary to check whether the weak current when the vehicle is stationary is too large. If the vehicle is stationary, the weak current is too large. It is probably caused by the grounding of the electrical circuit in the car. If it is not handled early, it will cause safety hazards. At the same time, the battery will be shortened by prolonged discharge. The automotive maintenance industry generally uses a clamp-on ammeter to detect weak currents when the vehicle is stationary.

What should I do if the battery freezes?

Since the battery liquid in the battery is water and sulfuric acid, the battery is likely to freeze at low temperatures. In the case of battery icing, what should I do as a car owner?

First of all, let's not study whether the battery liquid of the battery will freeze. Let's first look at what should we do after the battery freezes?

After the battery freezes, our vehicle will not start. We should remove the battery from the car, then move it to a heated place inside the room to allow the battery to melt before loading it into the car. Of course, in the evening, the battery is removed and taken to a warm place in the house to avoid the occurrence of battery icing.

Will the battery freeze?

　 The battery will freeze under the following conditions:

1) Adding too much distilled water causes the density of the battery liquid to decrease. At this time, the percentage of water in the battery liquid rises, causing the freezing point of the battery liquid to rise.

2) Excessive discharge leads to a decrease in electrolyte density, and an imbalance in the ratio of sulfuric acid to water causes the battery liquid to freeze.

How many degrees Celsius is the freezing point of the battery electrolyte?

The normal battery sulfuric acid concentration is 35%-40%. According to the "sulphate-water mixture freezing point curve", we can know that the freezing point of the electrolyte is between -60 degrees Celsius and -50 degrees Celsius. From the data point of view, as long as the battery liquid density is between 1.25-1.30, it is unlikely to freeze (unless you use the car in the very northern part of China).

However, as the concentration of sulfuric acid decreases, the freezing point of the battery liquid rises, which makes the battery liquid freeze. For example, Beijing's winter minimum temperature is generally below minus ten degrees. When the battery liquid density is as low as 1.10, the battery may freeze. The most common cause of the above changes is the excessive discharge of the battery.

How to avoid over-discharging the battery:

1) Avoid using high-power appliances when parking. High-power appliances include headlights, fog lights, seat heating, audio and air conditioning.

2) Check the headlights and the roof lights in the car before parking. In general, a normal fully charged battery can operate the headlights for two hours. As the rated capacity of the battery decreases, the time during which the headlights can operate normally is shorter. If you forget to turn off the headlights after parking, the vehicle's computer will not automatically turn off the lights, and the chances of not being able to drive the next morning will be 99%.

3) The battery negative should be removed when the vehicle is not used for a long time. Due to the weak current consumption in the vehicle circuit system during parking, standing the vehicle for a long time will cause the battery to run out. Therefore, for vehicles that are not used for a long time, we should unplug the battery negative to avoid excessive battery consumption.

to sum up:

In most parts of China, a good lead-acid battery will not freeze. The owners of the car owners should pay more attention to the battery of the vehicle, and regularly check the condition of the battery to avoid excessive discharge of the battery. If the battery has been used for a long time, and it is found that the vehicle has difficulty starting, the headlights are not bright enough, we recommend that the owners should replace the battery as soon as possible.