Understanding rechargeable batteries
In our quest to be mobile, we have come to rely on electronic gadgets to provide us with freedom to do our work anywhere. Reliance on them however made us dependent on rechargeable batteries for power. An understanding of rechargeable batteries can extend the life of our gadgets enabling more work done.
Rechargeable batteries are batteries that can have their energy restored to full charge when electrical current is passed through them in a reversed direction to that of the discharge. They are also called secondary cells or batteries.
The most common battery chemistries are Nickel Cadmium (NiCd), Nickel Meta-Hydride (NiMH), and Lithium Ion (Li-ion). NiCd batteries are the cheapest but have a relatively low capacity and high self-discharge rate. NiMH batteries are environment friendly and have higher capacity than NiCd. Li-ion batteries have very high capacity and very low self-discharge rate but are expensive. Handling Li-ion batteries must be exercised with great caution because they are flammable and tend to explode due to its very high capacity.
Rechargeable batteries are normally good for at around 1000 charge/discharge cycles. The number varies depending on how the battery is used. A battery that is recharged after a complete discharge will have lower charge/discharge cycle while a battery that is recharged after a partial discharge will have higher charge/discharge cycle.
Charge/discharge cycle should not be confused with “memory effect”. Memory effect or voltage depletion is a phenomenon observed in rechargeable batteries that causes them to lose their capacity temporarily. Memory effect can be reverse by fully discharging and recharging the battery once in a while.
Rechargeable batteries are rated by how much energy they hold. Usually express in terms of mAh (milli Ampere hour). A 1600mAh rated battery will last longer than a 1300mAh battery.