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Apple Computing Products:
macOS - Notebook Hardware
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<blockquote data-quote="Brown Study" data-source="post: 29273" data-attributes="member: 3889"><p>I recall reading on the web about recovering the charge of lithium ion batteries and tried to find the article but came up with a lot of junk and only this page, which is somewhat relevant and has a bit more information than the paragraphs I quote here:</p><p></p><p><a href="http://en.wikipedia.org/wiki/Lithium_ion_battery" target="_blank">http://en.wikipedia.org/wiki/Lithium_ion_battery</a> </p><p></p><p>"Li-ion batteries are not as durable as NiMH and NiCd designs, although they do not suffer from the memory effect. At a typical 100% charge level (notebook battery, full most of the time) at 25 degrees Celsius, Li-ion batteries irreversibly lose approximately 20% capacity per year from the time they are manufactured, even when unused. (6% at 0 degrees, 20% at 25 degrees, 35% at 40 degrees Celsius.</p><p></p><p>"When stored at 40% charge level, these figures are reduced to 2%, 4%, 15% at 0, 25 and 40 degrees Celsius respectively.) Every (deep) discharge cycle decreases their capacity. The degradation is sloped such that 100 cycles leave the battery with about 75% to 85% of the original.</p><p></p><p>"When used in notebook computers or cellular phones, this rate of deterioration means that after two to three years the battery will have capacities too low to be still usable."</p><p></p><p>Further down it says:</p><p></p><p> "A unique drawback that we can see to the Li-Ion battery is that its life cycle is dependent upon aging from time of manufacturing (shelf life) regardless if it was charged or not and not on the number of charge/discharge cycles. This drawback is not widely publicized."</p><p></p><p>Not publicized is an understatement.</p><p></p><p>Maybe the battery -- not the computer -- is two or three years old. The short shelf life explains the even shorter warranty.</p></blockquote><p></p>
[QUOTE="Brown Study, post: 29273, member: 3889"] I recall reading on the web about recovering the charge of lithium ion batteries and tried to find the article but came up with a lot of junk and only this page, which is somewhat relevant and has a bit more information than the paragraphs I quote here: [url]http://en.wikipedia.org/wiki/Lithium_ion_battery[/url] "Li-ion batteries are not as durable as NiMH and NiCd designs, although they do not suffer from the memory effect. At a typical 100% charge level (notebook battery, full most of the time) at 25 degrees Celsius, Li-ion batteries irreversibly lose approximately 20% capacity per year from the time they are manufactured, even when unused. (6% at 0 degrees, 20% at 25 degrees, 35% at 40 degrees Celsius. "When stored at 40% charge level, these figures are reduced to 2%, 4%, 15% at 0, 25 and 40 degrees Celsius respectively.) Every (deep) discharge cycle decreases their capacity. The degradation is sloped such that 100 cycles leave the battery with about 75% to 85% of the original. "When used in notebook computers or cellular phones, this rate of deterioration means that after two to three years the battery will have capacities too low to be still usable." Further down it says: "A unique drawback that we can see to the Li-Ion battery is that its life cycle is dependent upon aging from time of manufacturing (shelf life) regardless if it was charged or not and not on the number of charge/discharge cycles. This drawback is not widely publicized." Not publicized is an understatement. Maybe the battery -- not the computer -- is two or three years old. The short shelf life explains the even shorter warranty. [/QUOTE]
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