The car battery is dead and can't start. Should I replace it? Why do car batteries easily run out of power in winter?

The car battery is the power source for the entire vehicle. The headlights, dashboard, etc. all require battery power, and the battery is usually charged while driving. So if the car battery is dead and can't start, should you replace the battery?

The car battery is dead and can't start. Do I need to change it?

First of all, we need to find out the reasons why the car battery is low. The battery may be low for the following reasons:

1. The vehicle is parked for a long time, and the battery is discharged in the "dormant state", resulting in insufficient battery power and failure to start. Generally, the vehicle will fail to start due to insufficient battery power after being parked for about 3 months.

2. Forgetting to turn off the headlights when parking causes excessive battery power loss and inability to start the car.

3. Long-term use of high-power electrical appliances causes the car battery to run low.

4. The battery is aging and has reached the end of its service life.

A reliable method is to use a multimeter to measure the battery voltage and battery capacity. Because sometimes the battery voltage is normal, but the battery capacity is not enough, so the engine cannot be started normally. When the battery capacity is insufficient, the battery must be replaced.

If the battery is too exhausted to start the engine, you only need to call a rescue vehicle to connect the battery, start the engine and run it for a while, and the battery will return to normal. Therefore, there is no need to replace the battery in this case.

Why is it easy for car batteries to run out of power in winter?

Vehicle batteries, especially those in traditional fuel vehicles, are generally not subjected to particularly rigorous cold resistance tests. Basically, they are tested at normal temperatures to get a calibration data. Once the temperature drops, the capacity of the battery will definitely decrease.

On snowy days in winter, the temperature may be dozens of degrees lower than the normal calibrated temperature of the battery, and the battery capacity will drop significantly at this time. If the battery is more than two years old, the capacity may be even smaller. It is indeed possible that the battery will run out of power after five or six days.

The principle of low battery capacity at low temperature is that whether it is the lead-acid battery commonly used in car batteries or the ternary lithium battery installed in new energy vehicles, the activity of the compounds in the battery will be affected under low temperature conditions. If the activity of the compounds is affected, the battery's ability to store and discharge electricity will definitely be affected.

Therefore, when the temperature is low, the battery's storage and discharge capacity will be weakened. This is why car batteries are prone to running out of power in the winter and electric vehicles have insufficient range in cold conditions.

Although the capacity of the car battery may decrease in winter, as long as you don't stop driving for a week or two, it generally will not run out of power.

Why can't car batteries use lithium batteries?

The starting batteries used in automobiles generally include dry-type charged lead-acid batteries, valve-regulated sealed lead-acid batteries and lithium-ion batteries.

Disadvantages of lithium batteries compared to lead-acid batteries: poor low-temperature charging and discharging performance, poor safety during vibration and collision, generally relatively fragile, and more expensive.

The advantages of lithium batteries over lead-acid batteries are: lighter, larger capacity, better charging and discharging performance at room temperature, and better adaptability to the trend of electrification and electronic control.

In general, there is little need to replace lead-acid batteries with lithium batteries in traditional models. However, with the overall trend towards electrification, the demand for electricity from on-board equipment and the vehicles themselves is increasing. The disadvantages of lead-acid batteries, such as their bulkiness and limited capacity, are making them increasingly outdated.