Category: Digital Electronics
Description of the problem:
Regarding the "activation" problem of lithium batteries, many opinions are the following: Charging time must exceed Do this three times for 12 hours 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: the charging time should be greater at 12 p.m., and repeated 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 start. The charging and discharging characteristics of lithium batteries and batsNickel 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 automatically stop charging once the battery is full, which it is. does not exist. Nickel chargers have a so-called “maintenance” charge which lasts 10 hours. That is, if your lithium battery is fully charged and placed on the charger, it will be charged in vain. In addition, for some mobile phones, if you do not removenot 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 hear this saying: as the number of charges and discharges is limited, the power of the phone battery laptop should be used as much as possible. However, this statement is obviously false! Under normal circumstances, you should charge with reserves according to the principle of exhausting the remaining power of the batteryie, then recharge it (but certainly not turn it off and recharge it when it is impossible to hold the whole thing). 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 widely spread saying, such as long-term charging, is "try to use the mobile phone battery, and it is better to use automatic shutdown." This approach is actually only applied to nickel batteries. The goal is to avoid the memory effect. Unfortunately, it also spreads to lithium batteries. Someone one daycomplained about the battery level of his cell phoneAfter the low warning appears, the battery continues to be used without being charged until it turns off automatically. As a result, the mobile phone in this example was unresponsive during subsequent loading and startup and had to be sent for maintenance. This is actually because the battery voltage is too low due to over-discharge, so it does not benefit from normal charging and power-up conditions. Practical experience proves this: the scrap rate of lithium batteries with a depth of discharge of 100% is 50% (years of facts have proven that only half of the maintenance supplies of lithium batteries with a depth of 100% discharge of more than 99% can be activated, and the remaining half is discarded!)
Correct approach to lithium battery cell phones
ForTo sum up, my most important tips for charging and discharging lithium battery cell phones during use are:
1. According to the standard time and charging schedule, even for the first three times, first plug the charger (line charger), 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: Everything is fine Some brands of mobile phones cannot charge the mobile phone's backup battery (the small lithium battery on! the motherboard, which powers the 32.768 clock crystal) when it is turned off and charged. It can only be charged directly in standby mode.
2. When the cell phone battery is too low. , you should try to start charging as soon as possible; lithium batteries are plus susceptible to damage if over-discharged!
3. No special method is required to activate the lithium battery. is activated naturally during normal use of the mobile phone. If you insist on using the popular “first three charges and 12 hour activation” method, it will actually not be effective. Generally speaking, charging time is between 2 and 4 hours depending on battery capacity. Therefore, all practices that seek 12 hours of ultra-long charging and use lithium battery mobile phones to automatically shut down are wrong!
The charger can charge and discharge B+ and B-, but cannot charge and discharge P+ and P-, which indicates that the protection board is broken.
It can be used if you absolutely guarantee that the battery will not be overcharged, discharged or short circuitedee. However, there is always a danger when a short circuit occurs, and it is easy to catch fire. Damage to the protection board will usually cause the main MOS to burn out due to discharge. The main reason is poor design on the part of the manufacturer and failure by short circuit.
When the battery voltage is between 2.5V and 4.3V, the first and third pins of the DW01 both output a high level (equal to the voltage of power supply) and the voltage of the second pin is 0V. At this point, the voltage from the first and third pins of the DW01 is added to the fifth and fourth pins of the 8205A, respectively.
The two electronic switches of the 8205A are both in the on state because the G pole receives the voltage from DW01, that is, both electronic switches are in the open state. At this time, the negative electrode of the battery is directly connected tothe P terminal of the protection board, and the protection board has a voltage output.
First, the ternary parameter: generally 2.8~4.25, lithium iron is 2.5-3.65V.
1. Overvoltage, overdischarge, overcurrent, short circuit and overheating.
2. Use a multimeter to measure whether the charge and discharge MOS tube is open.
3. If the lithium battery protection board has an LED and cannot be charged or discharged, the LED will flash for 0.5 seconds to trigger an alarm.
4. When the lithium battery protection board has a host computer, you can connect to the host computer to check the protection status.
5. The lithium battery protection board has a low switch. Please check if the low switch is turned on.
If the above problems occur, you can repair them using the following methods.