6 major operational misunderstandings about battery charging and discharging
Times:08/21/2018 Hits:1642
Mistakenly believe that the new battery should use cyclic charging and discharging to activate the performance of the battery. The truth is: Accurately speaking, the above statement is not a rumor. There is a time difference between the lithium battery and the user, which is as short as one month and as long as half a year.
Activation of new battery
Mistakenly believe that the new battery should use cyclic charging and discharging to activate the performance of the battery.
The truth is: Accurately speaking, the above statement is not a rumor. There is a time difference between the lithium battery and the user, which is as short as one month and as long as half a year. For batteries with a long time difference, the electrode material will be passivated. Therefore, it is recommended that the battery used for the first time be subjected to a complete charge and discharge process 3 to 5 times in order to eliminate the passivation of the electrode material to reach the maximum capacity. But usually manufacturers do not pay attention to remind consumers, the full charge and discharge mentioned here should not be deep discharge, but should be controlled at 5% ~ 8%. Otherwise a new battery is likely to be scrapped.
"First three times" charging
Mistakenly: When a new battery is bought back, it is best to perform three cycles of charging and discharging. The charging time should exceed 12 hours to activate the battery's maximum performance.
The truth is: NiMH batteries need to go through the “supplement” and “turbulence” processes in order to achieve the perfect saturation state, which is usually about 5 hours. At present, the "constant current" and "constant voltage" charging characteristics of lithium-ion batteries control their deep charging time within 4 hours. Once fully charged, the internal protection circuit of the battery will automatically stop charging, so this practice is unscientific and has no practical significance.
Someone has tried it with a mobile phone. After charging the battery with the travel charger, switch to the charger to check the saturation of the battery. When he found that the charger was still charging the battery, he thought the battery was still not saturated. In fact, this test method is not rigorous. The reason is that the indicator light of the charger is not the only standard for detecting true saturation. The reference voltage of the charger is not necessarily equal to the reference voltage of the mobile phone. Therefore, when the mobile phone thinks that the battery is saturated, the charger is charged. Maybe I don't think so, I still charge, but if I charge it, I only know it.
Best state
Misunderstanding: As long as the rechargeable battery is used properly, it will appear in the best state within a certain cycle range to reach the maximum capacity.
For example, early nickel-metal hydride and nickel-cadmium batteries, if properly used and regularly maintained, will reach their maximum capacity in 10 to 200 cycle points (the capacity of nickel-hydrogen batteries with a factory capacity of 1000 mAh after 100 cycles is possible) Up to 1100 mAh).
The truth is: this statement is more common in Japanese product batteries and is usually seen in the cycle characteristics chart in its technical specifications. However, for the current mainstream lithium-ion batteries, the peak phenomenon of this cycle does not exist. Because the lithium-ion battery is shipped from the factory to the end of its life, its capacity is once less cycled, and there has never been a rebound in capacity. Maybe a friend will ask, some ThinkPad notebook users can restore the battery capacity through deep discharge. In fact, that is just the error detection of the test software, and the actual capacity of the battery has not improved at all.
Is there a best condition for lithium-ion batteries? The answer is yes, which is related to changes in the ambient temperature it is exposed to. Under normal circumstances, lithium-ion batteries will exhibit excellent performance in the environment of 25 ° C ~ 40 ° C. When it comes to low temperature or high temperature, its performance will be greatly reduced. For example, if you use a laptop while the sun is shining outdoors, it will not be used indoors for a long time.
capacity
Mistakenly: For two batteries with the same nominal capacity (for example, 800mAh), if an actual measured capacity is 860mAh and the other is 805mAh, then 860mAH must be better than 805mAh.
The truth is: In general, lithium-ion batteries of different models (different volumes) have a higher capacity for longer use. If you let go of factors such as volume and weight, of course, the higher the capacity, the better. However, it is not necessary for two batteries with the same nominal capacity (for example, the above example). Because of the battery having a high actual capacity, it is highly probable that a substance for increasing the initial capacity is added to the electrode material, and the substance for stabilizing the electrode is reduced. The result is that after a few dozen cycles, the block with high capacity decays rapidly, while the one with low capacity remains strong. In order to reduce costs and expand sales, many domestic manufacturers often use this method to produce high-capacity batteries. After half a year of use, users will find that working hours are greatly reduced. In short, the cost of increasing capacity is to sacrifice cycle life, manufacturers are not in the material context of the battery, it is impossible to really improve battery capacity.
Battery storage
Misunderstanding: If the rechargeable battery is not used, it should be discharged and stored.
The truth is: In fact, not only the rumors mentioned above, the lithium-ion battery should be full of preservation or radiant preservation will definitely make many people confused? The answer to this question should be discussed from its congenital flaws, which is the "aging effect." After being stored for a period of time, the lithium-ion battery will permanently lose part of its capacity even if it is not recycled. This is because the positive and negative materials of lithium-ion batteries have started their depletion process since they were shipped from the factory. The magnitude of aging at different temperatures and saturation levels is also different, as shown in the table.
It can be seen that the higher the storage temperature and the fuller the battery charge, the greater the capacity. Therefore, for long-term storage of lithium-ion batteries, users should control their power at 40% and store them at 15 ° C or lower. As for those nickel-metal hydride and nickel-cadmium batteries, there is no such "aging effect". After long-term storage, only a few full charge and discharge cycles can be used to restore their original capacity.
Fully charged follow-up charge
Mistakenly: When charging the battery, charge it for 12 hours, then it will help to increase the saturation of the battery.
The truth is: Under normal circumstances, a qualified charger will automatically turn off the charging circuit after charging is completed, there is no current, even if the battery is placed for another 10 hours, it will not help. Most mobile phone chargers currently sample such designs. Therefore, when the green indicator light is on, simply take the battery down and use it.