The TRUTH about the iPod BATTERY and CHARGING

[saqib]

found this for ya:

Aging of lithium-ion is an issue that is often ignored. lithium-based batteries have a lifetime of 2-3 years. The clock starts ticking as soon as the battery comes off the manufacturing line. The capacity loss manifests itself in increased internal resistance caused by oxidation. Eventually, the cell resistance will reach a point where the pack can no longer deliver the stored energy, although the battery may still contain ample charge.

and

Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate.

and if you want to get really technical about it: have a look at this:


Figure 1: Permanent capacity loss of lithium-ion as a function of temperature and charge level.
High charge levels and elevated temperatures hasten permanent capacity loss. Improvements in chemistry have increased the storage performance of lithium-ion batteries.

most of the above is from: How to prolong lithium-based batteries

[iPod Master]

why do you need to charge it for 3 hours on first use?

[Phoenix]

i was gonna post the link for batteryuniversity too

this page(direct link) is very interesting.... and i also put it in my sig

http://www.batteryuniversity.com/parttwo-34.htm

(mostly what pple have posted here already.... but the url is just the direct link to the page)

[DarkJC]

Just to clear a myth, NO PRIMING IS NEEDED FOR THE iPOD BATTERY. Charging for 3 hours before first use does not do anything to battery performance, and you will get the same life out of it if you don't. A discharge and recharge before first use is also UNNECESSARY.

[Liquid]

www.ipodbattery.com

[Doug Gilmour]

Guys check out this site: www.ipodsdirtysecret.com watch the video and see what the people did when they got angry with Apple's battery problem.

[saqib]

Originally posted by Doug Gilmour
Guys check out this site: www.ipodsdirtysecret.com watch the video and see what the people did when they got angry with Apple's battery problem.

Yeah that was posted some time ago; its funny but kinda redundant now.

[Mountain Man]

For the record, the nicad "memory effect" is an urban legend. Nickel cadnium batteries do not "remember" their charge cycles; instead, what people generally experience is damage from poor battery maintainence. When a nicad battery is over discharged or overcharged, it can cause the polarity of some some cells to reverse which will obviously decrease the effective life of the battery. So ironically, those folks who fully discharge their nicad batteries before recharging are actually causing the so-called "memory effect" instead of preventing it! Incidentally, this applies to all recharable batteries (including lithium ion like in the iPod).

In short, don't let your recharagable batteries deeply discharge and recharge them for the recommended length of time and you should be fine.

[saqib]

Originally posted by Mountain Man
So ironically, those folks who fully discharge their nicad batteries before recharging are actually causing the so-called "memory effect" instead of preventing it!

Incidentally, this applies to all recharable batteries (including lithium ion like in the iPod).

do you have any sources to back this up i'd be very interesed to see, cause from the advice i've seen is that overcharging lithium ion batterys does no harm to the battery.

I would like to see what school of thought subscribes to the idea that the above effects found in Ni-Cd abd Ni-Mh also directly apply to commerical lithium ion batteries.

[saqib]

Originally posted by Mountain Man
So ironically, those folks who fully discharge their nicad batteries before recharging are actually causing the so-called "memory effect" instead of preventing it!

Incidentally, this applies to all recharable batteries (including lithium ion like in the iPod).

In short, don't let your recharagable batteries deeply discharge and recharge them for the recommended length of time and you should be fine.

i've found this:

Much attention is focused to avoid over-charging and over-discharging. Commercial lithium ion packs contain a protection circuits that limit the charge voltage to 4.30V/cell, 0.10 volts higher than the voltage threshold of the charger. Temperature sensing disconnects the charge if the cell temperature approaches 90?C (194?F), and a mechanical pressure switch on many cells permanently interrupt the current path if a safe pressure threshold is exceeded. Exceptions are made on some spinel (manganese) packs containing one or two small cells.

buried in this article: Charging lithium-based batteries

which goes on to support the idea that there is no harm done by charging a lithium ion battery for longer than the quoted time.

also this is also a direct quote from another page on the above site:

Should I charge my battery partially or fully?
Does not matter. Charging in stages is acceptable. Full charge termination occurs by reading the voltage level and charge current. Charging a full battery is safe and does not cause harm.

[Mountain Man]

It is very difficult if not impossible to over charge or over discharge modern electronics devices as they have protection circuitry to prevent this. Most battery care advice only applies to older consumer electronics which lacked such protection putting the rechargable batteries at a much greater risk of being damaged.

As for my source about nicads and the myth of battery memory, A NiCd Never Forgets. Or Does It?, QST, November 1994, pp. 70-71.

[unmelodicgenius]

my battery is claiming that it's only quarter full when i charged it all night....is this right?

[Calculus]

this will probably correct itself within a few minute, most people know that the battery meter is very unreliable in 2.1 firmware

[darkfusion]

Turn it on and leave it playing, the battery meter will gradually creep back up to max, like a car's fuel guage.

[flamesburn]

hey I was just wondering if anyone knew if it was ok to keep your ipod in the dock when not using it, will this shorten the life as its continually charging? any info would be great