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Memory effect, also known as battery effect, lazy battery effect, or battery memory, is an effect observed in nickel cadmium and nickel–metal hydride rechargeable batteries that causes them to hold less charge. It describes the specific situation in which NiCd and NiMH batteries gradually lose their maximum energy capacity if they are repeatedly recharged after being only partially discharged. The battery appears to "remember" the smaller capacity. ==True memory effect== The term "memory" came from an aerospace nickel-cadmium application in which the cells were repeatedly discharged to 25% of available capacity (plus or minus 1%) by exacting computer control, then recharged to 100% capacity without overcharge.〔 This long-term, repetitive cycle regime, with no provision for overcharge, resulted in a loss of capacity beyond the 25% discharge point. True memory cannot exist if any one of the following conditions holds: * Batteries achieve full overcharge. * Discharge is not exactly the same each cycle, within plus or minus 3% * Discharge is to less than 1.0 volt per cell.〔(Repair FAQ, quoting GE tech note )〕 True memory effect is specific to sintered-plate nickel-cadmium cells, and is exceedingly difficult to reproduce, especially in lower ampere-hour cells. In one particular test program designed to induce the effect, none was found after more than 700 precisely-controlled charge/discharge cycles. In the program, spirally-wound one-ampere-hour cells were used. In a follow-up program, 20-ampere-hour aerospace-type cells were used on a similar test regime. Memory effects showed up after a few hundred cycles.〔(Repair FAQ, quoted above, but not directly quoting GE tech note )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Memory effect」の詳細全文を読む スポンサード リンク
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