The nominal voltage of a single cell is generally: 3.6 V or 3.7 V.
The charging voltage is generally: 4, 20V (lithium cobalt oxide is 4.2V-4.3V).
The minimum end-of-discharge voltage is generally: 2.75 V. A voltage lower than this voltage can easily lead to a significant reduction in battery capacity or even its disposal.
Maximum charging termination voltage: 4.20 V.
Diameter: 18 ± 0.2 mm.
Height: 65 ± 2.0 mm.
Capacity: Above 1000 mAh, normal capacity is 2200 mAh to 3200 mAh. LG has the highest 18650 battery capacity, which can reach 3600mAh, but the price is not low.
How to buy lithium batteries
1. Is the capacity clearly marked? Batteries without clearly marked capacity (such as 1000 mAh or 1000 mAh) are most likely using lower quality batteries or batrecycled materials. Many inexpensive batteries on the market are made from recycled batteries. Although they are cheap, their lifespan is short and their unstable quality can damage the phone.
2. Is there guaranteed standby time? Standby time is the duration of continuous use from the time the battery is installed in the phone until the next charge. Generally, batteries sold in the market cannot guarantee standby time to customers. This is because the battery quality is unstable. Many cheap batteries use poor quality battery cores, so the standby time is very short.
Lithium-ion batteries must be fully charged before storage. It can be stored for more than six months at 20°C, which shows that lithium-ion batteries are suitable for low temperature storage. Someone has aday suggested that it was indeed a good idea to keep rechargeable batteries in the refrigerator compartment. Lithium-ion batteries have a self-discharge phenomenon. Long-term storage will cause the battery to over-discharge, destroy the internal structure of the battery and shorten its service life. Therefore, lithium-ion batteries stored for a long time should be recharged every 3 to 6 months, that is, charged to a voltage of 3.8 to 3.9 V (the best storage voltage of lithium batteries is approximately 3.85 V).
Notes
When using lithium-ion batteries, pay attention to three points: When using lithium-ion batteries, it should be noted that the battery will enter a sleep state after being left for a period of time, the capacity is lower than normal, and the usage time is also shortened. However, lithium-ion batteries are feasy to activate. After 3-5 normal charge and discharge cycles, the battery can be activated and restored to its normal capacity. Due to the characteristics of the lithium battery itself, it has almost no memory effect. Therefore, users do not need any special methods or equipment during the activation process of new lithium batteries. Not only is this true in theory, but in practice the “natural activation” method of loading using standard methods from the start is best.
As for the "activation" problem of lithium-ion batteries, many opinions are: the charging time should be more than 12 hours, and repeated three times in order to activate the battery. This claim that "the first three charges require more than 12 hours" is obviously a continuation of the claim regarding nickel batteries (such as nickel-cadmium and nickel-hmetal ydride). This statement can therefore be considered misinformation from the start. There is a very big difference in the charging and discharging characteristics of lithium ion batteries and nickel batteries. All serious formal technical information points out that overcharging and overdischarging will cause huge damage to lithium batteries, especially liquid lithium ion batteries. Therefore, it is best to charge according to standard time and methods, especially not to charge for more than 12 hours. Additionally, lithium-ion batteries or chargers automatically stop charging once the battery is fully charged. There is no so-called “maintenance” charge that lasts more than 10 hours with nickel battery chargers. In other words, if your lithium-ion battery is fully charged and placed on the charger, it will charge in vain. And no one canIt can be guaranteed that the characteristics of the battery charge and discharge protection circuit will never change and the quality is foolproof, so the battery will be on the verge of danger for a long time. This is another argument against a long charge.
On some machines, if you do not remove the charger after charging for more than a certain time, the system will not only stop charging, but also start a discharge-charge cycle. Perhaps the manufacturer of this approach has its own agenda, but it obviously hurts battery life. At the same time, long-term charging takes a long time and often has to be done at night. Judging from the power grid situation, the voltage at night is relatively high and fluctuates significantly. As mentioned earlier, lithium-ion batteries are very delicate and much less resistant to charge and discharge fluctuationse than nickel batteries, which presents additional dangers.
In addition, another aspect that cannot be ignored is that lithium-ion batteries are also not suitable for over-discharge, and over-discharge is also very detrimental to the battery. This brings us to the next question. Since the number of charges and discharges is limited, the lithium battery should be exhausted as much as possible before recharging. However, the experimental table data on charge and discharge cycles of lithium-ion batteries is listed as follows:
Lifetime (10% DOD): >1000 times
< p>Lifetime (100%DOD):> 200 times where DOD is the English abbreviation for depth of discharge. The table shows that the number of recharges is related to the depth of discharge. The lifespan at 10% DOD is much longer than at 100% DOD. Of course, if converted to real load relative total capacity: 10% * 1000 = 100, 100% * 200 = 200, full charge and discharge of the latter is even better. Under normal circumstances, you should reserve the remaining battery capacity accordingly. au The principle of charging is to recharge when the battery is exhausted. However, if it is not expected to last all day on the second day, of course you should start charging on time. carrying the charger to the office is another matter.When it is necessary to charge to meet upcoming important events that are expected to cause charged communication, even if the battery still has a lot of energy remaining, simply charge it in advance, because there is no charge. actual loss of "1" Charge cycle life, i.e. "0.x" times, and often this. When the machine battery runs out, it is best to use automatic shutdown. This method is actually only used on batteriesnickel. The goal is to avoid the memory effect. Unfortunately, this is also common on lithium-ion batteries. Once upon a time there was an example of someone continuing to use the machine without charging it until it automatically turned off after a low battery warning. Therefore, the machine in this example did not respond for. subsequent charging and startup, and had to be sent to customer service for repair. This is actually because the battery is too discharged and the voltage is too low, so it doesn't have normal charging and starting. starting conditions. In the final analysis, the most important problem is the charging and discharging of lithium-ion batteries in use. The tips are: 1. Charge according to standard time and procedure, even for the first three times; When the machine low battery prompt appears, you should try to start charging as soon asas possible ; 3. There is no need to specialize in activating the lithium battery method, the lithium battery will activate naturally during normal use of the machine. insist on using the popular method of "first three activations of 2 hours charging", it will actually not be effective
Therefore, it is wrong to pursue 12 hours of ultra-long charging and use lithium.
4. Pay attention to fire prevention when using lithium batteries
Many people may make mistakes. I only became familiar with lithium-ion. Power batteries from cell phones. In fact, they are used in many household appliances. There is no doubt that the advantages of lithium ion power batteries are their high efficiency and light weight. to be light, efficient and resistant to low temperatures (-40°C). A bat0.3mm thick pad-sized lithium battery can be used continuously for more than 5 years and is widely used in many high-end household and mobile appliances. telephones.
p>Lithium-ion batteries are different from the water-soluble zinc chloride and potassium hydroxide electrolytes of manganese batteries and alkaline dry cells. They use organic solvents. Ion batteries use manganese dioxide, lead fluoride, sulfur chloride and other materials. Compared with the zinc chloride used in the negative electrodes of general batteries, the metal lithium foil used in the negative electrode has a stronger ionization tendency and a greater voltage difference between the positive. and negative electrodes, which improves the operating efficiency of lithium-ion batteries.
However, lithium-ion batteries often generatent heat and burn during use. In some cases this will affect host usage. , and in severe cases it will burn the host and cause fires. There have been numerous cases of house fires caused by burning lithium-ion batteries.
So why lithium-. Do Ion Batteries Heat Up and Burn? It turns out that many materials in lithium-ion batteries can undergo violent chemical reactions and release large amounts of chemicals when in contact with water. The thermal energy causes the manganese dioxide to heat up and burn. The lithium battery electrode may generate heat when exposed to a small drop of water. When the sulfur chloride in the lithium battery comes into contact with water, it generates hydrochloric acid and sulfur dioxide and releases heat.Yes, there are several factors that make lithium batteriesum a “fire” in life. Therefore, people should pay attention to waterproof and humidity when using lithium batteries. After various hosts are out of service, lithium batteries should be removed and stored in a dry and low temperature place to prevent and avoid house fires caused by improper use of lithium batteries.