Why electric cars can't run far in winter?

Enter winter, the temperature drops, all kinds of electric products also began to drop out of the range of problems, even if full of electricity, life is better than before to reduce a lot of.Unidentified truth consumers may doubt was pit, bought a few months, life volume has shrunk so much, many merchants, pled.So why will appear this kind of circumstance?Actually this is all the storage battery common fault.

The temperature influence

First of all, most of the electrodynamic transport at the model for 18650The lithium battery, including 18 said to 18 mm in diameter, 65 said length is 65 mm, 0 means for cylindrical batteries.

The 18650 model lithium battery

Lithium battery internal structure is mainly composed of the positive and negative, between across the electrodes and the electrolyte.Battery discharge, the principle of lithium ion precipitation was negative in a chemical reaction, through dielectric movement to the anode, then the positive on rich lithium, lithium anode in a poor state, in the process of lithium ion activity, creates an electric current produced by the electronic movement.

And in the case of the temperature decrease, this process of charging and discharging speed will slow down.So the discharge current smaller, battery capacity is small.Lithium battery labeling working temperature is 0 to 40 ℃, but in fact, when the temperature is below 25 ℃, there will be a certain degree of performance degradation, battery capacity reduced, the discharge speed slower, smaller battery power output, etc.

Below is the temperature of the lead-acid battery and lithium battery capacity curve, you can see the lithium battery capacity can reach 100% when 25 ℃, and under 25 ℃, capacity curve appeared a downward trend.Due to the lithium battery in 25 ℃ can reach maximum capacity, so this is also in all kinds of range test temperature can be set to as experiment temperature 25 ℃.

, of course, the above table is only one type battery data are for reference only, in fact because lithium battery materials and technology of the differences, the data will also have different.But the Internet has a relatively simple calculation, is:

On the basis of 25 ℃, 1 ℃ drop in temperature, electric capacity fell about 1%.That is to say, you in the summer, 25 km (25 to 28 °) can run car, 5 ° conditions in the winter, only consider cell factor, you may only be able to run up to 20 kilometers.

Temperature range caused by lower are reversible, the rise of temperature, and to restore the life of the car.This shows that electrons and people, the winter is don't want to move ah.

High temperature for lithium battery itself is influential, when temperature is higher than 45 ℃ destroy chemical equilibrium in the battery, harmful side effects, also reduces the lithium battery life, reduce the lithium battery capacity.So in the normal environment, the use of biggest factor affecting the operation of the lithium battery is the temperature.Also use mobile phone at the time of the day is cold power lithium-ion batteries can also use more quickly, and battery capacity decreases due to the temperature influence.

Charge and discharge frequency effect

Except, of course, the temperature, the influence of lithium battery capacity is one of the factors of charge and discharge frequency.According to the online query to the experimental data,18650 lithium batteries at 25 ℃ when the complete 50 times circulation charge and discharge, discharge capacity remain at 96.6%.In 18650, for example, cycles of 400 ~ 500 times (a cycle is equal to the battery completely filled to completely discharge process), the battery capacity will generally fell by 10% - 20%.

For example, if you have a use lithium battery electric vehicle, life can reach 25 km, charge once a day filled with electricity and exhausted, then about a year and a half or so, life is only 20 km or so.But it is calculated according to the actual use, if every day just using the 50% of the electricity charge, it is equivalent to 2 days time cycle, that is likely to be after three years life will decline by 20%.

The cause of the lithium battery capacity loss is due to the electrode in the battery as the filling process gradually loss, and temperature drops temporarily change the battery capacity is different, this is an irreversible process.

In addition to the charge and discharge can cause electrode loss, overcharge will also cause the electrode.But now most of the lithium battery can protect control with charging, so even with plug has been smart disconnect charging, so basically can avoid overcharge.

The maintenance of the electric car battery

1. Deposit winter when using the electronic equipment of lithium-ion batteries, the best move to indoor, reduces the natural electrical loss.Due to the lithium battery is slightly higher than that of discharge temperature, temperature charging so best on indoor temperature is 0 ~ 25 degrees Celsius, charging efficiency is higher.

2. Summer don't put lithium batteries placed under the environment of high temperature for a long time, will reduce the service life.

3. Long time no use lithium-ion batteries will charge on a regular basis, it is best to lithium battery power remain at around 30%.

4. Suitable for use in increases with the increasing charge, lithium-ion batteries and charging a indicates a charge and discharge cycle, that there has been no electric charge, so it is not recommended for lithium battery internal electrode has a larger damage.

5.Use the rated voltage, high charging voltage can speed up the charge, but also will damage the lithium battery life.

The page contains the contents of the machine translation.