Battery memory effect, do lead acid batteries have a memory effect?

Battery memory effect refers to the phenomenon that if the battery is a nickel-cadmium battery, it is easy to leave traces in the battery and reduce the battery capacity if it is not fully charged and discharged for a long time.

The battery memory effect means that the battery seems to remember the user's daily charging and discharging amplitude and mode, and it is difficult to change this mode over time, and it can no longer be charged or discharged by a large amount. Lithium-ion batteries do not have this effect.

Causes.

Due to the sintering type of the negative electrode in the traditional process, the cadmium grains are coarse, and if the nickel-cadmium cells are recharged before they are completely discharged, the cadmium grains are easy to aggregate into lumps and form a secondary discharge platform when the battery is discharged.

The battery stores this discharge platform and uses it as the end point of the discharge in the next cycle, although the capacity of the battery itself allows the battery to be discharged to a lower platform. The battery will only remember this low capacity during subsequent discharges. Also in every use, any incomplete discharge will deepen this effect, making the capacity of the battery even lower.

1 Recognize the memory effect.

The battery memory effect refers to the reversible failure of the battery, that is, the performance of the battery to recover after failure. The memory effect refers to the tendency of a battery to automatically maintain a specific duty cycle after it has been subjected to a specific duty cycle for a long time. This was first defined in nickel-cadmium batteries, nickel-cadmium pouch batteries do not have a memory effect, and sintered batteries have a memory effect.

Today's nickel-metal hydride (commonly known as nickel-metal hydride) batteries are not subject to this definition of memory effect.

Because of the improvement of modern nickel-cadmium battery technology, the above-mentioned memory effect has been greatly reduced, and another phenomenon has replaced this definition, that is, nickel-based batteries"Lattice"Typically, nickel-cadmium batteries are affected by a combination of these two effects, while nickel-metal hydride batteries are only affected"Lattice"memory effect, and the effect is smaller than that of nickel-cadmium batteries.

In practical application, the method of eliminating the memory effect has strict specifications and an operating process. Improper operation can be counterproductive.

For nickel-cadmium batteries, the normal maintenance is regular deep discharge: an average of one deep discharge per month (or 30 cycles) of use (discharge to each section, foreigners call it.

exercise), usually use photocells or use shutdown and other means to alleviate the formation of memory effects, but this is not exercise, because instruments (such as mobile phones) will not be used.

If it is turned off at each section, special equipment or wiring must be used to complete this work, and fortunately, many NiMH battery chargers have this function.

For nickel-cadmium batteries that have not been exercised for a long time, due to the accumulation of memory effects, it is impossible to recover the capacity with exercise, and at this time, a deeper discharge (called recondition) is required, which is a process of discharging the battery to each section for a long time with a small current, which requires professional equipment.

For nickel-metal hydride batteries, the frequency of exercise is about once every three months to effectively alleviate the memory effect. Because the cycle life of nickel-metal hydride batteries is much lower than that of nickel-cadmium batteries, the recondition method is hardly used.

Suggestion 1: It is not necessary to discharge the battery before each charge, and it is harmful because the service life of the battery is unnecessarily shortened.

Suggestion 2: It is not advisable to use a resistor to connect the positive and negative poles of the battery for discharge, the current cannot be controlled, it is easy to overload to 0V, and even lead to the reversal of the battery polarity of the series battery pack.

The memory effect is when a battery is charged many times and then it is no longer fully charged, and the battery thinks it is full. It's the memory effect.

The memory effect is an effect of crystallization of the contents of the battery due to the use of the battery, which is generally only produced in nickel-chromium batteries, less nickel-metal hydride batteries, and no such phenomenon in lithium batteries. The cause of this is due to the incomplete repeated partial charging and discharging of the battery. This will cause the battery to temporarily reduce its capacity, resulting in shorter talk time.

Lead-acid batteries have no memory effect. Although lead-acid batteries can also have capacity decay if they are not used properly, it is sulfidation, not memory effect. And the memory effect and vulcanization are not the same way to deal with it.

The response to the memory effect is to drain the battery with regular deep discharges, while the response to vulcanization is to try to fully charge it every time.

Lead-acid batteries have developed into lead-acid maintenance-free batteries and gel maintenance-free batteries, and there is no need to add electrolyte or distilled water in the use of lead-acid batteries. It is mainly used to produce oxygen at the positive electrode, which can be absorbed at the negative electrode to achieve oxygen circulation, which can prevent the reduction of moisture. When the discharge is carried out, the concentration of the sulfuric acid solution will continue to decrease, and when the density of the solution decreases to , it should be stopped for charging.

Unlike other secondary batteries, lead-acid batteries have no memory effect, which means that lead-acid batteries do not need to be discharged before charging. Theoretically, all lead-acid batteries can be recharged anytime and anywhere after they have been replaced.

However, due to the limitation of the number of charging and discharging times of lead-acid batteries, it is also necessary to charge the electric vehicle battery at the most appropriate time, so as to maximize the service life of the electric vehicle battery. Generally speaking, the new battery of the newly replaced electric vehicle, due to the impact of its own self-discharge, generally only has about 70% of the power left from the factory to the user's car. For electric vehicles, users can use it up to 30% and then charge it, so the charging effect is optimal.

The lithium battery used now basically does not have a malignant memory, that is, it is not used up, and it will not be like the mobile phone battery in the past, and only the capacity when charging can be used.

The mobile phone is generally used to 20%, it will prompt the power with the answer, and it can be charged directly if there is a condition, and the power is full, and the charger can be unplugged after a while.

It should be said that the mobile phone will be pre-charged when it leaves the factory, and the new mobile phone will have power when it is turned on, which means that the battery has been hail, and it has been tested by frequent charging and discharging.

Of course, although there is no malignant memory in the mobile phone, there is a limit on the number of charging times, try to use the mobile phone for as long as possible, and you can charge it below 10% to reduce the number of charging times.