AGM technology was developed in 1985 for military aircraft to reduce weight, increase power handling and improve reliability. The acid is absorbed by a very fine fiberglass mat, making the battery spill-proof. This enables shipment without hazardous material restrictions. The plates can be made flat to resemble a standard flooded lead acid pack in a rectangular case; they can also be wound into a cylindrical cell.
The growth has been in secondary batteries (rechargeable) but non-rechargeable or primary batteries are equally important. They continue to fill an important niche market in applications such as wristwatches, remote controls, electric keys and children’s toys. Primary batteries also assist when charging is impractical or impossible, such as military combat, rescue missions and forest-fire services.
Rechargeable batteries play an important role in our life and many daily chores would be unthinkable without the ability to recharge an empty battery. Points of interest are specific energy, years of service life, load characteristics, safety, price, self-discharge, environmental issues, maintenance requirements, and disposal.
Batteries come in all shapes and sizes and there could be as many types as there are species of dog. Rather than giving batteries unique names as we do with pets, we distinguish batteries by chemistry, voltage, size, specific energy (capacity), specific power, (delivery of power) and more.