Secondary (Rechargeable) Batteries
Secondary batteries are the rechargeable batteries. They have the advantage of being more cost-efficient over the long term, although individual batteries are more expensive. Generally, secondary batteries have a lower capacity and initial voltage, a flat discharge curve, higher self discharge rates and varying recharge life ratings. Secondary batteries usually have more active (less stable) chemistries which need special handling, containment and disposal. Ni-Cd and small-size lead acid batteries require special disposal and should not be simply thrown away.
Advantages
Best solution for high drain applications
For high utilisation applications the cost of the charger is soon paid back.
Shortcomings
Cost of charger. For low cost applications such as toys the charger could cost much more than the product it supports.
Safety issues with mains power.
Lower energy density than primary cells unless exotic chemistries used.
Lack of standards
Many custom pack designs and limited interchangeability. (Disadvantage for the user but creates a captive aftermarket for the manufacturer)
Applications
Traction
Power tools
Motor drives
Laptop computers
Mobile phones
PDAs
Camcorders
Toys
Typical Battery Chemistries
Alternatives
Lead Acid
Lithium
Nickel Cadmium (NiCad)
Nickel Hydrogen
Nickel Iron (NiFe)
Nickel Metal Hydride (NiMH)
Nickel Zinc
Zebra (NaNiCl)
See also Primary Batteries and Alternative Energy Storage Methods
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