Apple Portables: About battery storage life
Summary
Apple uses four different types of batteries for portable computers (other than MacBook Air):
- Sealed lead acid (SLA)
- Nickel cadmium (NiCad)
- Nickel metal hydride (NiMH)
- Lithium ion (Li-Ion)
MacBook computers use lithium ion batteries. Each type of battery has different storage life characteristics.
Products Affected
iBook, MacBook Pro, MacBook, PowerBook
Sealed Lead Acid Batteries (SLA)
- 2 to 3 months - Battery should still have minimal charge to operate the PowerBook
- 12 to 18 months - Battery can still be charged
Nickel Cadmium Batteries (NiCad)
- 1 to 2 months - Battery should still have minimal charge to operate the PowerBook
- 6 to 12 months - Battery can still be charged
Nickel Metal Hydride Batteries (NiMH)
- 1 to 2 months - Battery should still have minimal charge to operate the PowerBook
- 6 to 12 months - Battery can still be charged
The Portable Intelligent Battery (NiMH) has improved charging abilities. A fully charged battery has a 6-month shelf life. If the battery is discharged in sleep as far as it will go to the point that the computer shuts down, the computer can stay in this state for 6 weeks.
Lithium Ion Batteries (Li-Ion)
- 1 to 2 months - Battery should still have minimal charge to operate the computer
- 6 to 12 months - Battery can still be charged
- 12 months or more - Uncertain
Additional Information
Batteries may be damaged if stored for prolonged periods with a closed circuit. The environmental temperature also affects the storage life of any battery. Cool environments are best, and are assumed for the above estimates. All storage times are based on storage starting with the battery fully charged.
For example, schools that may not use their Apple Portable computers during a long weekend or break should fully charge the batteries, remove them from the computers, and store them in a cool location for the duration of the break.
For additional information, see this page.