Battery Life and Battery Maintenance for Pure Electric Vehicle

How long does the battery life of an electric car last?

Although electric cars are now cheap to charge compared to conventional fuel vehicles, the cost of replacing batteries will be huge due to the high price of electric cars themselves and the relatively short battery life. Therefore, cost barrier "battery repair and maintenance" has become the "road Tiger" for universal electric vehicles. For an electric car, the larger the battery range, the more convenient it will be, and the larger the range, the lower the frequency of charging.

However, the life of an electric car depends on the motor. Different driving Motors, their costs are also very different. If DC brush motors are used, the on-board power supply can directly supply the motor, using this motor to use thyristor controller chopper speed adjustment.

Batteries have "dry storage life" and "wet storage life". These two concepts are only for the battery self-discharge size, not the actual life of the battery. The true life of the battery refers to the actual length of time the battery is used.

For a primary battery, the lifetime of the battery is a representation of the working time given the rated capacity (related to the size of the discharge multiplier).

For secondary batteries, the battery life is divided into two kinds: the cycle life of charge and discharge and the service life of wet shelving.

The cycle life of charge and discharge is an important parameter to measure the performance of secondary batteries. To undergo a charge and discharge is called a cycle(or cycle). Under a certain charging and discharging system, before the battery capacity is reduced to a certain specified value, the number of charged and discharged times that the battery can tolerate is called the cycle life of the secondary battery. The longer the cycle life, the better the battery performance. Among the commonly used secondary batteries, cadmium nickel batteries have a charge-discharge cycle life of 500-800 times, lead-acid batteries of 200-500 times, lithium-ion batteries of 600-1000 times, and zinc and silver batteries of about 100 times.

The cycle life of secondary batteries is related to discharge depth, temperature, and charging and discharging system. The so-called "discharge depth" refers to the percentage of capacity released by the battery as a percentage of rated capacity. By reducing the discharge depth(ie, "shallow discharge"), the cycle life of the secondary battery can be greatly extended.

Wet shelving service life is also one of the important parameters to measure the performance of secondary batteries. It refers to the time when the battery begins the charging and discharging cycle after the electrolyte is added to the battery(including the time when the battery is in discharge and wet shelving during the charging and discharging cycle). The longer the service life of wet shelving, the better the battery performance. Among the commonly used batteries, cadmium nickel batteries have a wet shelving life of 2 to 3 years, lead-acid batteries for 3 to 5 years, lithium-ion batteries for 5 to 8 years, and zinc silver batteries for the shortest, only about 1 year.

In addition, the performance of the battery is: low temperature performance, over charging ability, safety performance and so on.

In recent years, the sales of new energy vehicles in China have increased dramatically, and the number of power batteries that exceed the warranty period has also shown an increasing trend. The new energy vehicles currently on the market, including BYD, meet or even exceed the battery warranty requirements for new energy tax-free models. Take Biyadiqin as an example. At present, the factory has given "6 years or 150,000 kilometers of warranty and lifetime warranty for the electric core", while the SAIC Rongwei E50 provides 3.1 million kilometers of warranty for the entire vehicle. It also deliberately provides 5.1 million kilometers of warranty for core components such as batteries. Beiqi, on the other hand, provided its E150ev battery with a five-year, open-ended commitment.

What are the biggest concerns consumers have about batteries?

Is the battery safe?

Leakage? Spontaneous combustion? An explosion? Security issues are the biggest concern.

To this end, the state issued a "safety order" for the demonstration and promotion of new energy vehicles, and strengthened the monitoring of the working conditions of power cells and fuel cells; Manufacturers are also increasing their research on the safety of pure electric car batteries, which indicates that the safety of new energy vehicles has gradually become on the right track.

What effect does the charging time have on the battery

Pure electric vehicles are generally charged quickly and slowly. Fast charging uses a large current to charge the battery directly through a non-vehicle charging machine, and can fill the battery 80 capacity in half an hour; Slow charging refers to AC charging. The charging process takes 6 hours to 8 hours.

What's wrong with the battery?

This is a safety redundancy in the battery, reserving part of the battery to prevent overcharging and excessive discharge. For example, the original battery capacity is 100 %, but the real usable is about 80 % -90 %. The value of the redundant power is the real power that the owner can use.

Because during the charging process, the battery can not be filled too full, nor can it place the electricity in space. If the battery is filled with every time, its service life will be greatly reduced; Too full, once the charging system fails, it may cause a safety accident due to "overcharging."

Points to Note for Battery Use

Batteries look pretty precious, and it's especially important to keep your motor and battery in good condition if you want to extend the life of a pure electric car. How do you pay attention to battery life extension?

1, how to correctly master the charging time?

Answer: According to the actual situation, grasp the charging time and frequency, refer to the usual use frequency and mileage. When driving normally, if the electricity meter indicates that the red light and the yellow light are on, it should be charged; If only the red light is left, it should stop running and charge as soon as possible. Otherwise, excessive discharge of the battery will seriously shorten its life. After full power, the running time is shorter and the charging time is not too long. Otherwise, over-charging will form, causing the battery to heat up. # Overcharging, excessive discharge, and under-charging can shorten the battery life #.

2, how to protect the charger?

Answer: The charger is basically not designed to be high vibration resistant, so try to avoid the jolting vibration of the charger. After the charger vibrates, its internal battery will drift, causing the entire parameter to drift, causing the charging state to be abnormal. Keep the charger ventilated when charging, otherwise heat drift may occur and affect the charging state.

Is it OK to bask in the sun for a long time?

A: Don't even think about it. It's absolutely impossible! The high temperature environment will increase the internal pressure of the battery and cause the battery to lose water, causing the battery activity to decline and accelerating the aging of the polar plate.

Why should the battery be fully discharged and charged?

A: A full discharge of the battery at regular intervals can slightly increase the battery capacity. After completing the complete discharge, the battery will be fully charged and the battery capacity will be felt to increase.

5, how to avoid plug heat when charging?

A: When the 220-volt power plug or charger output plug is loose and the contact surface is oxidized, it will cause the plug to heat up. If the heating time is too long, the plug will short-circuit or contact poorly, damaging the charger and battery. You should remove oxides or replace connectors in a timely manner.

Why do you charge every day

A: Daily recharging can make the battery in a shallow cycle, and the battery life will be extended. Most chargers may be 97 % to 99 % charged after the indicator lamp is changed to indicate full power. Although only 1 % to 3 % of the charge is undercharged, the impact on the renewal ability is almost negligible, but it will also form under-charging accumulation, so the battery must continue to float charging as much as possible after being filled with electric lights.

7, how to avoid high current discharge?

A: When electric vehicles are started, manned, and uphill, try to avoid stepping on acceleration. Instantaneous high current discharge will have an impact on battery life.

What should be noted for the cleaning of electric cars?

A: According to the normal car wash method, during the cleaning process, care is taken to avoid water flowing into the body charging socket to avoid short circuit of the body line. Wash the vehicle with neutral washing agent. The mixture of cleaning agent should be carried out according to the instructions of the manufacturer. Soak the cleaning liquid with soft cloth. Do not rub hard to avoid damaging the paint surface.

9, how to do regular inspection?

Answer: to the company's sales center or the maintenance Department of the agent for inspection, repair or distribution group.

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