二次电池技术提供能量存储的折衷方案

　　二次电池技术提供能量存储的折衷方案

　　电池供电系统现在已经普及，这得益于新的电池化学技术的发展，使得能够为越来越广泛的系统提供能量。二次电池已成为重要的能源来源，为电子系统提供了比原系统更为环保的解决方案，因为它们可以充电而不是要求新电池，而旧电池在运行时会被丢弃。

　　如果不作为主要电源，二次电池可以在许多消费和轻工业应用中发挥重要作用，在主电源故障时提供必要的后备电源。它们可以充当能量源，以节省电源，或者允许原电池进行交换，而不会丢失存储在易失性存储器中的宝贵数据。充电技术的使用使他们能够充分充电，并准备支持系统，利用主要能源的能源。这确保了正常运行时间不会随着时间的推移退化，因为它将使用一次充电电池。

　　主要有四种类型的可充电电池供电，现在普遍使用的电子电气设备：密封铅酸电池；镍镉（NiCd）电池；镍氢（NiMH）电池和锂离子电池。它们各自都有各自的特点，但也有一些共同的特性。

　　大多数电池化学成分在供电方式上是非线性的。电池的容量与它所提供的电流有关；通常，电池的电流越大，电池的有效容量就越低。例如，电流为5毫安时，电池容量可能为1000毫安。然而，同一电池的容量为500毫安，电流为200毫安。

　　Further， the chemistry and construction of a secondary cell have a strong bearing on the way in which it can be recharged and discharged and its ability to sustain a high enough voltage to power the circuit. Some chemistries can provide high discharge or charge rates， but their output voltages can drop quickly at some point， possibly beyond the ability of the load circuit to continue performing. As a result， the load is unable to use all the energy available. A further consideration is how quickly the energy can be restored to the battery once the main power supply has been reactivated， and whether the cell can be charged regularly or it is best to perform a deep discharge followed by a recharge.

　　The memory effect in batteries is particularly noticeable for NiCd cells， which suffer reductions in their useable capacity if they experience repeated shallow cycling. For example， if the interruptions to power are short lived and frequent and the batteries are recharged each time， the memory effect will lead to a fall in their effective maximum capacity.