What is the memory effect

Battery memory effect refers to the battery reversible failure, that battery failure recovery performance. Memory effect refers to the battery for a long time in particular work cycle, automatically keep this particular work trend. This was first defined in the nickel-cadmium batteries, the bag nickel-cadmium battery does not exist memory effect, while sintering batteries have. And now the nickel-metal hydride battery is not restrained by the definition of memory effect.

Because modern nickel-cadmium battery technology improvements, the memory effect has been greatly reduced, while the other phenomenon replaces the definition, that is, nickel-based batteries "lattice", usually, nickel cadmium batteries by both effects of the combined effect of the nickel-metal hydride battery only by the "lattice" of memory effect, but also affect the relatively small nickel-cadmium batteries.

In practice, the elimination of the memory effect has the strict specifications and an operation process. Improper operation will be counterproductive.

For nickel-cadmium batteries, regular maintenance is periodic deep discharge: the average use per month (or 30 cycles) to a depth of discharge (discharge to 1.0V / each section, or call it exercise), normal use is to try to run out of battery or use other means to shut down the formation of memory effect can be mitigated, but this is not exercise, because the instrument (such as mobile phones) is not used 1.0V / per session before the shutdown, it must be specialized equipment or lines to complete the work Fortunately, many of NiMH battery charger comes with this feature.

For long-term no exercise nickel-cadmium batteries, because of the cumulative memory effect, cannot exercise to restore capacity, when you need a deeper discharge, which is a very small current to the battery for a long time discharge to 0.4V each section a process that requires specialized equipment.

For NiMH batteries, exercise frequency conducted once every three months to mitigate memory effect effectively. Because NiMH battery cycle life is far below the nickel-cadmium battery, almost no recondition this method.

▲ Recommendation 1: It is not necessary to discharge the battery before charge, and also harmful, because the battery life is shorten.

▲ Recommendation 2: Use a resistor connected to the positive and negative of battery to discharge is not desirable, the current cannot be controlled, easy to reach 0V, and even lead to series battery polarity reversal.