Battery

A battery is a hardware component that provides electrical power to a computer or device, so that it can operate independently, or at least maintain time and some settings, while disconnected from a power source.

Early battery technologies at Apple
The Macintosh Portable, introduced in September 1989, was the first battery-operated Macintosh from Apple Computer that could run without a power supply. It featured a heavy (typically used in automobiles) that contributed to its considerable weight of 15.8 lb. The first PowerBook 100 series, released in October 1991, adopted the use of  (NiCad) batteries, which reduced size and weight. The PowerBook Duo series, introduced in October 1992, adopted the used of (NiMH) batteries, which reduced the "" incurred during repeated battery s. The NiMH batteries went through 3 revisions of improvements and it is not recommended to leave the battery dormant in the computer for more than a week without charging.



Lithium technology
The PowerBook 5300 series, introduced in August 1995, was the first to adopt (Li-ion) battery technology. However, as a few early production models overheated and caught fire, Apple immediately reverted to nickel–metal hydride (NiMH), which provided only 70% of Li-ion capacity. Later iPod and MacBook models were introduced by Apple with batteries that contained pressed spools of sheets instead of traditional cylindrical cells, to further compact power density.

Disposal
Batteries contain chemicals that may be hazardous to the environment. Apple will accept and recycle used batteries from its products that are returned to any of its Apple retail stores or authorized service providers.

Articles

 * How to avoid damaging your iPhone's battery health by Andrew O'Hara at AppleInsider (2021-12-21)