Pacific Automotive Network Overcharging and overdischarging will damage lithium iron phosphate batteries. Overcharging will cause lithium dendrites, and overdischarging will cause copper dendrites, resulting in short circuits, malfunctions and other problems; Lithium batteries require shallow charging and discharging. At present, when using lithium batteries, protection circuits should be installed as much as possible to ensure safety. At the same time, lithium iron phosphate battery is a relatively safe type of lithium battery.
When overcharging, the battery voltage increases rapidly with increasing polarization, which will cause irreversible changes in the structure of the positive active material and decomposition of the electrolyte. A large amount of gas will appear and one. A large amount of heat will behas been released, which will cause the battery temperature to decrease. The internal pressure increases sharply, and the internal diaphragm melts or shrinks, causing the positive and negative electrode materials to contact and short circuit, causing explosion, combustion and other hidden dangers.
Over-discharge: Over-discharge refers to further discharge when the voltage reaches the rated voltage. For example, the rated discharge voltage of a ternary lithium-ion battery is 3.2V if it continues to discharge. when it is less than 3.2V, it is over-discharge. What damage does over-discharging cause to the battery?
Once the battery has discharged the internally stored energy and the voltage has reached a certain value, continued discharge will cause the battery to overdischarge which can have catastrophic consequences for the battery, in particularier excessive current discharge. Repeated excessive discharge will have a greater impact on the battery. Generally speaking, excessive discharge will increase the internal pressure of the battery, destroy the reversibility of positive and negative active materials, decompose the electrolyte, deposit lithium on the negative electrode, and increase resistance. Even if it is loaded, it can. will only be partially restored, and the capacity will also be significantly attenuated.
One: Use a special protection board (BMS) for lithium-ion batteries to work with the battery. The protection board can protect the battery from overcharging or overdischarging. The smart version can also adjust the charging voltage. and discharge voltage, which can better protect the battery.
Second: Use the corresponding lithium-ion battery charger instead of fast charging.
Three: whenthe battery voltage reaches the voltage set by the protection board, the protection board cuts off the power to protect the battery, but the lithium-ion battery drops and the voltage increases, which will be a little higher than the voltage adjusted by the protection panel. It can no longer be used at this time. Repeated use will cause irreversible damage to the battery.
The lifespan of lithium-ion batteries is determined. First of all, there is one objective fact that cannot be changed, and that is the lifespan of a cell phone battery. It is somewhat similar to the human lifespan. People who worry too much can lose years of their life. have good lifestyle habits, they can live for a few more years. The same goes for lithium-ion batteries. If you use them correctly, you can use them for a few more years, but if you handle them, their lifespan is limited.will be very short. Just like human life, no matter how hard you try, it will eventually end. The same goes for lithium-ion batteries, even if you don't use them, they will age slowly. Moreover, it is still irreversible aging, so if the mobile phone battery capacity has been lost, there is no way to restore it to the state of the new phone.
The operating principle of lithium-ion batteries is very simple. Charging and discharging are actually chemical reactions inside the battery, regardless of the type, they will undergo the movement of ions from the negative electrode to the positive electrode. or from the positive electrode to the negative electrode, forming positive and negative electrodes. The polar compounds change as the reaction proceeds, and the loss of the battery is actually the reduction in ionic activity.
(Images/Text/Photos: Pacific Autom Q&Aotive Network Calling Beast)
Category: Digital Electronics
Question Description:
Regarding the problem “ activation" of lithium batteries, many people say that the charging time should be more than 12 hours and repeated three times to activate it, but some people say this is wrong. Which statement is correct?
Analysis:
Regarding the "activation" problem of lithium batteries, many opinions are as follows: Charging time should exceed 12 hours, repeat this three times to activate the pool. 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-metal hydride). This statement can therefore be considered misinformation from the beginning. The charging characteristics andDischarge of lithium batteries and nickel batteries are very different, and we can tell you very clearly 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. The claim in many cell phone manuals that new batteries must be charged for more than twelve hours is false!
Additionally, cell phones or chargers with lithium batteries will lose power once the battery is discharged! is fully charged. Automatically stops charging, and there is no so-called “maintenance” charge that lasts more than 10 hours with nickel chargers. In other words, if your lithium battery is fully charged and placed on the charger, itwill be loaded in vain. In addition, for some mobile phones, 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. Maybe the manufacturer of this approach has their own agenda, but it obviously harms the life of the battery and the cell phone/charger.
In addition, another aspect that cannot be ignored is that lithium batteries are also not suitable for over-discharge, and over-discharge is also very detrimental to lithium batteries.
When should you start charging during normal use
We often see this saying: Since the number of charges and discharges is limited, it should to be exhausted. battery of your cell phone as much as possible before recharging it. However, this statement is obviously false! In circumstancess normal, you should charge with reserves according to the principle of depleting the remaining power of the battery and then recharging it (but certainly not turning it off and recharging when it is impossible to hold the whole). day for 2 days, you must start charging on time! And when you need to charge to meet upcoming important events that are expected to result in charged communications, even if the battery still has plenty of power remaining, then you can simply charge. move forward, because you're not really losing the life of a charge cycle. The principle of recharging once the remaining battery power is exhausted is not to go to extremes! A popular saying like long-term charging is “try to use the cell phone battery. It is best to use "automatic shutdown". This method is actually only used on nickel batteries to avoid the memory effect. MUnfortunately, it is also common on lithium batteries. There were people who still didn't respond due to a warning about their mobile's low battery. This is an example of charging and using until it turns off automatically. Therefore, the mobile phone in this example did not respond during subsequent loading and booting and had to be sent for maintenance. be over discharged and cause the voltage to be too low. This is due to the lack of normal charging and starting conditions. Actual experience proves that the scrap rate of lithium batteries with 100% depth of discharge is 50% (years of fact). proved that only half of lithium batteries with a depth of discharge above 99% can be activated, the remaining half are discarded!)
The correct approach of the lithium battery. cell phones
To summarizeWed, my opinion on lithium battery cell phones is as follows. The most important tips for charging and discharging problems during use are:
1. Charge according to the standard time and procedure even for all three first times. First connect the charger ((online charging), plug in the power, and then plug the output end of the charger into the charging port of the mobile phone. Some people want to ask: is it better to charge with the phone on or with the phone off? Answer: Both are OK Some brands of cell phones cannot be charged when they are off charge the backup battery in the cell phone (the small lithium battery on the board. mother, which powers the clock crystal 32.768). The backup battery can only be charged by direct charging in standby mode!the cell phone is too weak, you should try to start charging it as soon as possible; lithium batteries are more vulnerable to damage when over-discharged!
3. Activation of lithium batteries No special method is required. The lithium battery will activate naturally during normal phone use. If you insist on using the popular "first three activations of 12 hour charge" method, it won't actually work. to be efficient. Generally speaking, it depends on the battery. Depending on capacity, charging time is between 2 and 4 hours. Therefore, all practices that pursue 12 hours of ultra-long charging and use lithium battery cell phones until they automatically turn off. people are wrong!