Lithium battery overcharge hazards need to be vigilant!

Recently, a fire broke out in a rental house. People living inside woke up to find that the sweater ball remover in the living room, which had been charged for two days spontaneously ignited. A random survey by the reporter found that 70% of the citizens had bad habits such as charging for a long time. Today, rechargeable batteries have become a necessity in people's daily life. How to charge the battery correctly and prevent accidents should arouse the public's concern.

Incident: the living room burst into flames at midnight because the sweater ball remover spontaneously ignited.

The reporter saw Ms. Zhang in a rented room near Zhonghuabei Street in ShiShi City, where she and her friend lived.

The scorched ball remover and a black jack were left in the corner of the living room. The smell of burning plastic could still be felt throughout the room.

The reporter noticed that the ball remover was about the size of an adult's palm, the pink handle had been blown into two halves, the iron mesh protecting the blade had been smoked into black, the fuselage had been seriously deformed, the original appearance could not be seen, and the burned wire was exposed outside. Next to it was the plug board that had been used at the time and its joints had been blackened.

"Thanks to early detection, otherwise the consequence is unimaginable." Ms. Zhang said that on March 21 morning before she going out, she wanted to take care of her pilling sweater, but the ball remover ran out of power."I inserted it on the lug plate in the corner of the sitting room, then went out shopping with friends, for the next two days I forgot all about it."

Until about 3 am on March 23, Ms. Zhang and her friend were suddenly awakened by a pungent smell of burning. They got up at once and turned on the light to check, only to find that a fire twenty or thirty centimeters high appeared in one corner of the living room. A stream of black powder rushed to the roof with black smoke and the pungent smell filled the whole room. At this time, Ms. Zhang suddenly remembered her long-forgotten sweater ball remover. It caught fire. She shouted to the frightened friend beside her, picking up the chair cushion at hand and put it on the flame, which was quickly put out. Her friend quickly cut off the power supply of the switchboard.

Ms. Zhang said the burning sweater ball remover was purchased at a night market four or five years ago and cost more than 10 Yuan. It has been in normal use for several years without any malfunction. As for the brand she never paid attention to it. The brand logo on the scorched ball remover was unrecognizable. "Who would have thought it would catch fire? It's lucky it happened without hurting anybody. Speaking of this matter, Ms. Zhang still has some fears.

Ms. Zhang said that she had forgotten to unplug the charger several times before, and that there were occasions when she charged the ball remover for two or three days, but there had been no accidents. The only difference between this charge and the previous one was that the plug board and the ball remover were placed in a position where they could be exposed to the sun. However, since the fire broke out in the early morning, she was not sure whether the sun exposure caused the fire.

Survey: Seventy percent of the people surveyed had a bad habit of charging for a long time

The reporter randomly surveyed 20 citizens in the street, 14 of whom had the bad habit of charging household appliances for a long time, and these citizens were not aware of the damage to electrical appliances.

Reporter investigated 20 citizens randomly in the street, including 14 people surveyed in charging for household appliances is the habit of charging for a long time, and these people don't know for a long time charging damage to the appliance.

Citizen Ms. Qiao said the tablet was a necessity for her before going to bed, and she would connect it to a bedside power supply to recharge it after reading it every day. "I wake up in a hurry to go to work in the morning, never turn off the power, and my tablet stays charged until I go to bed the next night." She said other gadgets such as electric toothbrushes and ball removers, often unplugged, and sometimes it takes two or three days to recharge before she remembers, "When the device is fully charged, it could automatically turn off power, so I don't worry too much."

Other citizens in the survey shared Ms. Qiao's views, but attitudes changed when they learned of Ms. Zhang's experience. "When you charge an electric car, sometimes you forget to unplug it after charging and it doesn't come back to you until two or three days later." Looking back, Mr. Wang said, 'I am a little scared.'

The good and bad are intermingled of market of charging equipment

Subsequently, the reporter visited a number of mobile phone battery, charger stores. At a mobile phone charging device store, sales staff showed a variety of mobile phone chargers at prices ranging from 10 Yuan to 200 Yuan. The salesman introduced that the charger is divided into the original factory and non-original factory types, the specific material and service life is also different.

Mr. Zheng, who was about to buy a charger, said he had bought a charger. But after using for two months, it was only able to charge once instead of twice. "When I took out the packaging box of the charger, I did not find the '3C' certification mark." Mr. Zheng said, charging equipment market is also very messy, the quality cannot be guaranteed, we should choose a qualified manufacturer.

View: the overcharge, overheating, short circuit and collisions are all triggers for batteries to explode and catch fire

Fires occur when batteries are being recharged. What are the causes of these fires? The reporter interviewed Ke-qiang Ding, professor of chemistry and material science at Hebei Normal University.

Ke-qiang Ding said the battery fire explosion, generally due to the battery internal active substances and electrolyte components chemical and electrochemical reactions causing large amounts of heat and gas. "Overcharging, overheating, short circuits and collisions are all factors that can cause batteries to explode and catch fire." ke-qiang Ding said that when the battery is overcharged, excess lithium ions overflow from the positive electrode and react with the solution, giving off power to heat the battery, causing the lithium metal to react with the solvent and lithium carbon embedded with the solvent, resulting in a large amount of heat and gas causing the battery to explode.

"But normally rechargeable batteries are equipped with protective circuits. Once the battery is damaged by over-voltage or over-current, the protection system will automatically recognize the damage and change from high current to low current. In this way, the battery will stop charging, so it will not cause fire and explosion." But some battery manufacturers may not have designed protective circuits because of price and other considerations, Ke-qiang Ding said. Under such circumstances, if a battery is charged for a long time, it is easy to react internally, generating a large amount of heat and gas, which can lead to fire and explosion accidents.

In addition, Ke-qiang Ding stressed that the battery short circuit or impact is easy to make positive thermal decomposition, generating a lot of heat, and then lead to the explosion of the battery and fire.

Warning: remove surrounding combustibles when charging

Battery explosions and fires often cause devastating damage to individuals and families. In order to use the battery and other charging equipment more safely, professor Ke-qiang Ding suggested that we should go through the regular channels and buy batteries from the regular manufacturers with 3C certification.

In addition, according to the characteristics of the battery, the public should also master the following correct habits of use.

1, Control charging time to prevent overcharging of the battery to reduce gas precipitation;

2, Use the original battery and charger as far as possible, and try not to talk for a long time while charging the phone;

3, Try to avoid charging the battery in high temperature, humidity and other adverse environments;

4, Choose a household plug board with high power and few interfaces. It is best to remove the surrounding combustibles in advance when charging the electric appliance. In addition, be sure not to charge the phone under the pillow or bed or other environment with poor heat dissipation;

5, When charging or storage, if found that the battery becomes hot, emits odor, color changes, deforms or other abnormal, please stop using;

6, Mechanical impact cell, fall, artificial short circuit cell is prohibited;

7,When use, it is forbidden to install the positive and negative electrodes of the battery in reverse;

8. Under no circumstances shall the cell be disassembled or dissected, because disassembly and dissection may cause a short circuit inside the cell;

9. In case of battery explosion or fire accident, you should pay attention to the preservation of on-site evidence, such as taking photos, finding witnesses and keeping accident electrical appliances, so as to protect your rights and protect your legitimate rights and interests.

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