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Correct Way to Charge an iPod?

Cliff posted more than 9 years ago | from the proper-care-and-feeding dept.

Media (Apple) 107

JAHA wonders: "I've seen two schools of thought regarding the proper method for charging an ipod so as to maximize the lifetime of the battery: let the iPod completely drain before re-charging; or keep the iPod completely charged as often as possible (i.e. leave it charging while you listen to it if you can). There doesn't seem to be any official word from Apple on their website, so I was hoping the smart people here could clear it up for me." For those looking for a definitive resource on the proper care and feeding of your iPod batteries, try this site.

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Discharge Batteries (4, Informative)

Syris (129850) | more than 9 years ago | (#7839177)

Apple Ipods use Lithium Ion batteries, like a lot of portable products.


The lifetime of a rechargeable Lithium Ion battery shortens considerably if it is left 'topped up' on a charger for extended periods of time(weeks, etc). That's one of the reasons they are never used as backup sources of power.


So, don't leave it on the charger. The battery will last longer.

Re:Discharge Batteries (1)

VisorGuy (548245) | more than 9 years ago | (#7839280)

It's also damaging to fully discharge NiMH & LIon batteries.

Re:Discharge Batteries (2, Informative)

Syris (129850) | more than 9 years ago | (#7839388)

That's a good point! Most modern pieces of consumer electronics will shut themselves off at extremely low battery voltages, though. So it's probably OK to listen to your Ipod until it turns off.

Re:Discharge Batteries (3, Interesting)

VisorGuy (548245) | more than 9 years ago | (#7840129)

Kind of like how most modern consumer electonics devices have smart chargers that stop charging the battery when it's full?

I know my Neuros works that way.

Re:Discharge Batteries (2, Informative)

Anonymous Coward | more than 9 years ago | (#7840671)

The apple dock stops charging when the ipod is full.
So, DO leave it on the charger. The parent is a moron.

Re:Discharge Batteries (-1, Troll)

The Infamous Grimace (525297) | more than 10 years ago | (#7841626)

Anonymous or no, you are definately a coward. And a moron.

(tig)

Re:Discharge Batteries (1)

KingArthur10 (679328) | more than 10 years ago | (#7861592)

One thing to consider is, if you leave it on the charger while listening to music, it will not be runing off of the power source, but rather the battery, which is constantly being charged, so it may reduce the life. I'm not certain on how their charging mechanism works, but this may be the case, in whiech, the parent is correct.

Re:Discharge Batteries (4, Interesting)

baryon351 (626717) | more than 10 years ago | (#7840945)

Depending on how the charging system works, that may or may not be relevant.

However, what MAY affect things is that I've noticed a great deal of iPods left connected to a mac do get very very hot.

One feature of a Lithium Ion battery is they age - and after around 3 years nearly every one made will be dead, it's just part of their chemistry. Heat drastically speeds up the ageing process in them, and I've no doubt that those iPods left connected and hot are killing their batteries.

I don't know what's causing it, whether it's a software bug that keeps the HD spinning, or an overcharging bug, or they're being used as a HD constantly, for an hour or more at a time, but that heat is damaging to battery life.

http://www.buchmann.ca/ has good lay-readable info about various battery technologies and their characteristics.

Re:Discharge Batteries (0)

bdsesq (515351) | more than 10 years ago | (#7845354)

However, what MAY affect things is that I've noticed a great deal of iPods left connected to a mac do get very very hot.

That is because the iPod disk is spinning while it is connected. When spinning continuously the iPod disk generates more heat than the iPod can disipate.

This is also another way to kill your battery. By cooking it!

Re:Discharge Batteries (1)

tuxedobob (582913) | more than 10 years ago | (#7848464)

Actually, if you leave it connected long enough without accessing it, the hard disk in the iPod will spin down. (You may need to check the appropriate system preference.) I leave mine plugged in all the time, and every now and then I need to wait for it to spin up so I can access a file on it.

Apple does say (somewhere) that you should remove the iPod from any and all carrying cases when charging it, but so far I've ignored that too.

I actually used it as a scratch disk for downloading about 3GB the other day. The hard disk was probably spinning for a good 9 hours or so. For that, though, I did take it out of its case and let the metal part sit on a wooden chair to help dissipate the heat.

Disk mode (1)

SuperBanana (662181) | more than 10 years ago | (#7848517)

Depending on how the charging system works, that may or may not be relevant.

The 'charging system' is, like almost all LiIon devices, managed by a dedicated IC. Go to Maxim's website- they have all sorts of chips specifically for this sort of thing. LiIon batteries pretty much can't be charged except by a very intelligent circuit. But yes, if you have a cheap charger on any other battery type, you will cause damage. Lead acid batteries are easily damaged if kept on an incorrect float current/voltage; I have a $60 5-stage charger for my lead-acid batteries that keeps them properly topped up for months at a time. Buy a $20 charger at Sears, and your battery will be dead in a manner of days/weeks.

However, what MAY affect things is that I've noticed a great deal of iPods left connected to a mac do get very very hot.

If the iPod is mounted, yes, my iPod(3rd gen) will get warm- warmer if left on a blanket or something that's not a very good heat conductor.

However, unmounted from the desktop and not charging, the thing's pretty much at room temp. It'll shut itself off and go to the 'charging' or 'charged' display after about 15-20 seconds afer getting unmounted, and that's that; it's basically off.

I think it speaks volumes against the "don't leave it plugged in" theory that Apple sells a dock which is designed to hold the thing all the time(and keep it charged all the time.)

Re:Disk mode (1)

Jahf (21968) | more than 10 years ago | (#7849476)

You do? I don't.

Apple knows the same thing that the rest of the computer industry does (as well as most car manufacturers) ... if you make a product with a great feature set but limited life span, you make more money as people return to buy another. You just have to balance how long the life of the product is so that it is -just- long enough not to make the product seem "cheap".

I was in 2 different compu-shops this season buying gifts. In one shop a lady was yelling at the salesman because she could not get anyone to replace her old iPod's battery and it only held 1/3rd it's original charge. In another, I listened to a sales person -explain- to a husband and wife that when the battery on the iPod they were considering died they would have to buy a new one. There were lots of decent portable music player alternatives. In -both- cases I noticed the people in the check-out line a few minutes later with new cheaper-but-not-cheap 10GB iPod.

If you think about it for a bit, it is nasty. That's alot of chemicals going into the dumpster after they opened their new iPods and junked the old ones. Apple quite purposely made a disposable product with a life just long enough to keep people barely happy enough to buy again. As with computers, I think such products should have a government mandated company paid-for disposal program.

A simple way to replace the battery would fix the problem, but would lose Apple money.

Re:Disk mode (1)

ahknight (128958) | more than 10 years ago | (#7866698)

Apple quite purposely made a disposable product with a life just long enough to keep people barely happy enough to buy again. As with computers, I think such products should have a government mandated company paid-for disposal program.

A simple way to replace the battery would fix the problem, but would lose Apple money.


-sigh- Just a little research, please? For $99, Apple will replace the battery and they will correctly dispose of the old one. Done.

Re:Disk mode (1)

jbrownc1 (589652) | more than 10 years ago | (#7853773)

I think it speaks volumes against the "don't leave it plugged in" theory that Apple sells a dock which is designed to hold the thing all the time(and keep it charged all the time.)
I think the only thing it speaks volumes of is that Apple made a dock which is designed to make it easy to synchronize the iPod with the computer. If you read any of the articles that were linked to in the initial post, you would see the lithium ion batteries have only two real enemies: time and heat. Full discharges do you no good, keeping it always topped up does you no real good, your lithium battery is gonna go to battery heaven in about 2 years, less if it is exposed to heat all the time, such as the heat in your car. This isn't an Apple issue, this is the state of battery technology today. Bottom line, leave it plugged in or don't, you'll get about the same battery life from your iPod.

Re:Discharge Batteries (1)

rspress (623984) | more than 10 years ago | (#7856806)

Most quick chargers shut off or trickle charge the battery and are not harmful to the battery. I have many NiCads and LiIon batteries that have well over 500 charging cycles and some 10 years old that are almost as good as the day I bought them.

If you care for your batteries they will last a very long time and if you don't, they won't. It is as simple as that. The article mentioned tells the right way to do it....if you don't follow those guidelines don't whine when your battery is dead.

Re:Discharge Batteries (1)

gotpaint32 (728082) | more than 10 years ago | (#7859310)

"How to prolong lithium-based batteries

Battery research is focusing heavily on lithium chemistries, so much so that one could presume that all portable devices will be powered with lithium-ion batteries in the future. In many ways, lithium-ion is superior to nickel and lead-based chemistries and the applications for lithium-ion batteries are growing as a result.

lithium-ion has not yet fully matured and is being improved continuously. New metal and chemical combinations are being tried every six months to increase energy density and prolong service life. The improvements in longevity after each change will not be known for a few years.

A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.

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. (Read more in 'Choosing the right battery for portable computing', Part Two.)

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.

The speed by which lithium-ion ages is governed by temperature and state-of-charge. Figure 1 illustrates the capacity loss as a function of these two parameters.

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.

There are no remedies to restore lithium-ion once worn out. A momentarily improvement in performance is noticeable when heating up the battery. This lowers the internal resistance but the condition reverts back to its former state with the temperature drops.

If possible, store the battery in a cool place at about a 40% state-of-charge. Some reserve charge is needed to keep the battery and its protection circuit operational during prolonged storage. The most harmful combination is full charge at high temperature. This is the case when placing a cell phone or spare battery in a hot car. Running a laptop computer on the mains has a similar temperature problem. While the battery is kept fully charged, the inside temperature during operation rises to 45C (113F).

Removing the battery from the laptop when running on fixed power protects the battery from heat but some battery and laptop manufacturers caution against it. They say that dust and moisture accumulating inside the battery casing could damage the laptop. The dealers will be happy to provide you with a new pack when a replacement is needed a little sooner.

A large number of lithium-ion batteries for cell phones are being discarded under the warranty return policy. Some failed batteries are sent to service centers or the manufacturer, where they are refurbished. Studies show that 80%-90% of the returned batteries can be repaired and returned to service.

Some lithium-ion batteries fail due to excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit opens and the battery appears dead. A charge with the original charger is no longer possible. Some battery analyzers (Cadex) feature a boost function that reactivates the protection circuit of a failed battery and enables a recharge. However, if the cell voltage has fallen below 1.5V/cell and has remained in that state for a few days, a recharge should be avoided because of safety concerns. To prevent failure, never store the battery fully discharged. Apply some charge before storage, and then charge fully before use.
Simple Guidelines

Avoid full discharges; recharge lithium-ion more often. Repetitive random charge does not harm the battery. There is no memory.

Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.

Consider removing the battery from a laptop when running on fixed power but some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.

Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing date. Do not buy old stock, even if sold at clearance prices."

Source: (http://www.batteryuniversity.com/parttwo-4.htm)

batteries (4, Informative)

aliquis (678370) | more than 9 years ago | (#7839237)

Ni-Cd: Drain them out completely and then recharge them until full.

Ni-Mh: I think it's same as above, but the memory effect isn't as bad as it is for Ni-Cd.

Lithium-ion: Try to keep them around 40% or so, never let them go completely empty.

I might be wrong thought.

Not good advice (3, Informative)

Uma Thurman (623807) | more than 9 years ago | (#7839426)

Don't drain your batteries. Cells in a pack will discharge at different rates. When one dies and is driven in reverse by the other cells, it will be permanently killed. ESPECIALLY NiMH.

Memory effect is real, but you will not ever notice it, unless you do dozens of discharge cycles that are all the same length, to an accuracy of a few seconds. This isn't going to happen in normal use.

Basically, use your iPod. Charge it when you like. Don't run it all the way down.

Re:Not good advice (2, Funny)

Uma Thurman (623807) | more than 9 years ago | (#7839495)

More on memory effect:

It is noticed on Earth satellites that spend very regular cycles in sunlight/charging and darkness/discharging. If you listen to your Brittany Spears songs for EXACTLY 30 minutes, then charge your iPod, repeated for a few weeks, you'll get a memory effect. I doubt that many people would do that.

Re:Not good advice (1, Funny)

Anonymous Coward | more than 9 years ago | (#7840426)

If you listen to your Brittany Spears songs for EXACTLY 30 minutes, then charge your iPod, repeated for a few weeks, you'll get a memory effect. I doubt that many people would do that.

Not me, that's for sure. There's no way I could limit my Brittany to just 30 minutes. She's the best!

Re:Not good advice (5, Funny)

spaceport (188705) | more than 9 years ago | (#7840524)

If you listen to your Brittany Spears songs for EXACTLY 30 minutes, then charge your iPod, repeated for a few weeks, you'll get a memory effect.

However, in addition to the memory effect, you will suffer from an even stronger lack of taste effect.

Oops, I posted again...

Re:Not good advice (0)

Anonymous Coward | more than 10 years ago | (#7843008)

Lithium Ion batteries do _not_ have the memory effect.

http://www.cellpower.com/battery_tips.cfm

http://biz.maxell.co.jp/english/batteries/pdf/ba tt eries02.pdf

Re:Not good advice (1)

tuxedobob (582913) | more than 10 years ago | (#7848404)

What, no one else has pointed out that he misspelled Britney Spears? Come on, you don't have to like her to have seen her name in print.

Re:Not good advice (0)

Anonymous Coward | more than 10 years ago | (#7856914)

but you DO have to be a complete twat to care if someone misspells her name.

you obviously knew who he was referring to.

Re:batteries (5, Informative)

dougmc (70836) | more than 9 years ago | (#7839550)

I might be wrong thought.
No, you're pretty close.

No battery likes being overcharged. NiCds handle it best, but it slowly eats away at them (assuming a slow charge.) Smart chargers will stop the overcharging, but most chargers for NiCd devices are not smart. So take them off the charger once the battery starts getting warm!

If they are overcharged, or never discharged fully, they'll start to show voltage depression (often mistakenly called memory.) A full discharge will usually resolve this, at least until the battery wears out.

NiMH cells are very like NiCds, but they have more capacity and handle abuse less well. They also don't suffer from voltage depression (often called memory) so there's no need to fully discharge them ever.

Never completely discharge either sort -- go down to 1.0 volts per cell and then stop. Going further can cause the weakest cell to be `reverse charged' making it even weaker. For normal users, this means just use the item until it needs to be charged, but don't just turn it on and leave it going overnight.

Li-Ion cells can *explode* if overcharged, so any decent charger will stop charging them before that happens. So they should be fine to leave on the charger forever.

They'll also die if fully discharged. Fortunately, most things that use them will turn off before this happens, for exactly that reason.

To be complete, lead-acid batteries (like used in your car) should not be overcharged, as it evaporates electrolyte. Good chargers will prevent this, and your car has a good charger in it. Do not leave them discharged for any length of time -- this will ruin them. Fortunately, they self-discharge very slowly, so they can be left alone for a year or so after a full charge and won't die (as long as there is no load.)

iPods and most laptops and cell phones have Li-Ion cells, though some older cell phones and laptops have NiMH cells (and even older ones may have NiCds.)

Re:batteries (1)

Hes Nikke (237581) | more than 9 years ago | (#7840193)

i hate to pick nits, but iPods and some PDA's have Lithium Ion Polymer [valence.com] batteries. Sadly, i don't know what properties Li-Ion Polymer batteries have verses standard Li-Ion cells, aside from the fact that Li-Ion Polymer is more of a flexible sheet rather then a AA shaped cell.

anyone have any more information? i know that the Li-Ion battery in my TiBook has seen a lot less memory effect in comparison to the Lithium Ion Polymer battery in my Clie. but then again, i keep my TiBook at a full charge most of the time, and i use my Clie off the grid a lot more than my TiBook.

Re:batteries (2, Informative)

dougmc (70836) | more than 10 years ago | (#7841476)

Li-poly batteries are very like Li-ion cells, but they're less likely to explode if overcharged. Beyond that, and the (possible) shape differences, I don't think there's much of a difference.

The link you gave explained it pretty well ...

i know that the Li-Ion battery in my TiBook has seen a lot less memory effect ...
The Li-whatever cells do not experience memory. (Even NiCd's rarely do under normal use, but voltage depression is often mistaken for it.) They do eventually wear out, however -- perhaps that's what's happening.

Re:batteries (0)

Anonymous Coward | more than 10 years ago | (#7843020)

> i hate to pick nits, but iPods and some PDA's have Lithium Ion Polymer batteries

Older iPods used LiIon Polymer batteries. Newer ones use LiIon.

http://www.ipodbattery.com/

Re:batteries (1)

be-fan (61476) | more than 10 years ago | (#7864315)

Not the 3rd-gen iPods. They use regular li-ion batteries.

Re:batteries (1)

Anti_Climax (447121) | more than 10 years ago | (#7843758)

The memory effect present in Ni-Cd batteries is caused by crystals of Cadmium forming on either the anode or cathode (I don't remember which). The memory effect is not supposed to happen in NiMH batteries as there is no Cadmium in them. The high capacity NiMH batteries I have tell me to keep them topped off as much as possible to prolong their useful life.

Li-Ion batteries do not have a memory effect that I know of, so there shouldn't be a problem topping them off, but I haven't heard if this is good or bad for them. I do know if they are drained too far that they can actually switch polarity. As such all Li-Ion cells have an integrated control which cuts them off before they can drain too far.

Re:batteries (1)

13S (658991) | more than 10 years ago | (#7849522)

Here is a great article [ussc.com] on batteries from a fellow Ham operator.

Re:batteries (1)

rspress (623984) | more than 10 years ago | (#7856816)

Mostly, but never drain ANY cell completely! This can cause a dead cell within the battery and it will need to be replaced or if you know the "trick" it might be revived.

keep it topped up (3, Interesting)

bobba22 (566693) | more than 9 years ago | (#7839271)

I have experienced problems with my iPod when I let it run down completely, it drops into 'zombie' mode and cannot be woken without unplugging the battery. This is a pain in the arse when I'm going to be away from my computer for a long time. The iPod is one of the first of the first generation and can now only hold charge for around an hour. I don't think that it'll make much difference how you do the charge/discharge dance, you just have to accept the fate that the battery dies. What we really want is sony to release the batteries to the general public (UK) so we can refit them cheaply ourselves.

Re:keep it topped up (0)

Anonymous Coward | more than 9 years ago | (#7839348)

A LiIon will not realyl ever run down "completely", like a NiCd or NiMH. The voltage drops off too quickly in Lithium based batteries, the device just plain won't be able to pull the power. It is not damaging at all to NiMH or LiIon batteries to drain them.

However, the overall lifetime of a LiIon battery is a lot less normally than the POTENTIAL lifetime of a NiMH or NiCd battery.

Re:keep it topped up (1)

hexdcml (553714) | more than 10 years ago | (#7843534)

What we really want is sony to release the batteries to the general public (UK) so we can refit them cheaply ourselves.

Whoa.. I'll have whatever you're smoking ;) not to be pedantic or anything but iPod = Apple product.

Re:keep it topped up (1)

pmhudepo (595903) | more than 10 years ago | (#7844107)

True, but the batteries may well be supplied by Sony.

Re:keep it topped up (1)

hexdcml (553714) | more than 10 years ago | (#7845194)

ahh.. yes. My bad - The batteries are indeed supplied by Sony. *le sigh*

Re:keep it topped up (0)

Anonymous Coward | more than 10 years ago | (#7856939)

http://www.ipodbattery.com/

there ya go. 50 bucks buys you a new battery. and a screwdriver. w00t.

Re:keep it topped up (1)

phatsharpie (674132) | more than 10 years ago | (#7845227)

I have a first generation iPod (it's about two years old now), and I actually listen to it until it tells me that it's out of battery/power before I recharge it. I have been doing this since day one, and it's been holding its charge fine. In fact, I don't even notice much battery degradation.

-B

Re:keep it topped up (1)

ChuyMatt (318775) | more than 10 years ago | (#7867915)

I too have a 1st gen iPod and have had no problems. Ok, i did, but that was solved by the update that corrected the power drain problem. If you thought you had a great lifetime on you battery and then put on the equalizer, shuffle and sound check, then THAT is the reason your battery is lasting all of 2 hrs.

quite simply, i think you must be doing something wrong if you are loosing you battery.

Re:keep it topped up (1)

JeffTL (667728) | more than 10 years ago | (#7846550)

You, dear sir or madam, are the proud owner of a portable hard drive / Firewire-loaded shelf system.

Re:keep it topped up (1)

stigin (729188) | more than 10 years ago | (#7862848)

http://www.ipodbattery.com/ Might help.

charge codes... (-1, Offtopic)

delorean (245987) | more than 9 years ago | (#7839277)

rats, I was looking for ideas on charge codes to get the company to buy one....

Plug it in (1, Insightful)

Kethinov (636034) | more than 9 years ago | (#7839387)

An iPod with a dead battery can still be plugged in to the wall. It might be possible to buy (or create) an external battery pack in which the electricity is converted from DC to AC and you could "plug it into" the battery pack. I'm not sure of this is possible, but if someone has setup something like this, perhaps using massive D sized batteries, you would never have to worry about the iPod's crappy battery ever again.

Of course this would ridiculously bloat the size of your iPod. The battery pack alone could be twice the size of the unit. In my case, if I ever bought an iPod I'd probably be using it at work mostly, and there's a wall to plug it into =p

Re:Plug it in (1)

GigsVT (208848) | more than 9 years ago | (#7839557)

What are you talking about?

Are you saying the Ipod takes AC wall power directly without using a wall wart?

Re:Plug it in (3, Informative)

oneishy (669590) | more than 9 years ago | (#7839576)

Yeah! Belkin already created a external battery pack. It's even sold on the Apple Store [apple.com] !

Re:Plug it in (0)

Anonymous Coward | more than 9 years ago | (#7839658)

Uhh why would you need to convert DC->AC? The white brick that plugs into the wall that gives you firewire out to charge your iPod does just the opposite. You simply have no understanding of AC and DC electricity so please don't offer your ideas for "electronic projects" where you are putting "massive D sized batteries" in a box and making the magical AC electrical stuff!!

Battery Rundown (5, Informative)

Leroy_Brown242 (683141) | more than 9 years ago | (#7839418)

This is my understanding from what I have picked up as time has gone by. Correct me if I am wrong.
  • NiCd
  • Short overall life span.
  • Developed "memory" easily.
  • Needed to be fully charged and drained every single time.
  • NiMH
  • Longer overall life span.
  • Develops a memory over time, but hard cycling of power and draining can remove it.
  • Best if fully charged and drained, but not required every time.
  • Li-ion
  • Longest life of most comercial batteries.
  • Much harder to develop a memory. Most people it wwould take months.
  • Hard on the battery if it's left full charged constantly.
  • Still best if fully drained and charged every time, but very forgiving.

Re:Battery Rundown (3, Informative)

dougmc (70836) | more than 9 years ago | (#7839815)

NiCd -- Short overall life span.
NiCds usually have less capacity than NiMH cells, but they last longer (more charge/discharge cycles.)
NiCd -- Needed to be fully charged and drained every single time.
No, not every time. Occasionally is good enough -- the more it's overcharged, the more often you'll need to fully discharge it.

NiMH cells do not show voltage depression (often called memory) so there's no need to worry about fully discharging them.

Li-Ion -- Hard on the battery if it's left full charged constantly.
No it's not. If the charger overcharges them, they could explode, so most chargers know when to stop. The real reason that people say not to leave them fully charged for long periods of time is that they can explode if accidently shorted out.

Li-ion cells are not at all forgiving -- if abused, they either die (fully discharged) or explode/burn (overcharged, short circuted.) It's the needed circuitry (to prevent these things from happening) that's forgiving.

Li-poly cells are more forgiving, but with most of the benefits of Li-ion cells. I don't know how popular they are outside of R/C applications, however.

Re:Battery Rundown (2, Informative)

Elwood P Dowd (16933) | more than 9 years ago | (#7840176)

Li-poly cells are more forgiving, but with most of the benefits of Li-ion cells. I don't know how popular they are outside of R/C applications, however.

And, of course, iPods. iPods are li-poly. They are only more forgiving in that if/when they explode or burn, you have a hunk of burning plastic rather than a pool of burning liquid. If they are physically damaged, there's no toxic fluid to leak everywhere.

Re:Battery Rundown (1)

forevermore (582201) | more than 10 years ago | (#7846373)

And, of course, iPods. iPods are li-poly.

Funny, Apple says otherwise: [apple.com]

Power and battery
* Built-in rechargeable lithium ion battery (630 mAh)

Re:Battery Rundown (1)

Elwood P Dowd (16933) | more than 10 years ago | (#7847402)

That is funny.

The first generation was definitely li-poly. They have either changed, or Apple doesn't feel that they need to make the distinction. (Li-poly batteries are li-ion batteries, if I understand correctly. In li-poly batteries, the ions are in a polymer substrate rather than a liquid.)

Re:Battery Rundown (1)

anthonyrcalgary (622205) | more than 10 years ago | (#7851901)

The other poster is correct.

It's damn near impossible to get the liquid li-ion batteries into something the size of an iPod. Most of the internal volume is occupied by the hard drive, leaving precious little for the battery. An advantage of li-poly batteries is that they can be made flat instead of round, which allows them to substantially reduce the external dimensions of iPods.

Re:Battery Rundown (1)

be-fan (61476) | more than 10 years ago | (#7864281)

You're both wrong :) The first and second generation iPods were li-poly. They had problems with these, so they moved to lithium-ion batteries in the third generation iPod. The battery life went down from 10 hours to 8 hours in the process.

Re:Battery Rundown (1)

Hes Nikke (237581) | more than 9 years ago | (#7840268)

Li-poly cells are more forgiving, but with most of the benefits of Li-ion cells. I don't know how popular they are outside of R/C applications, however.

well, you're closer to being on topic than you think, they use Lithium Ion Polymer batteries in the iPod, as well as in many PDAs

Good synopsis of single cell behavior, but ... (1)

brokeninside (34168) | more than 10 years ago | (#7841247)

... as a rule of thumb multi-cell battery packs should never be completely drained which can destroy individual cells within the pack leaving the capacity of the pack as a whole quite diminished.

Re:Good synopsis of single cell behavior, but ... (1)

dougmc (70836) | more than 10 years ago | (#7842330)

`Destroyed' isn't the right word. Damaged is a better term ... of course, each time it happens it makes the weakest cell a little weaker, eventually making the pack as a whole almost unusable (due to that weak cell.)

I've not seen the iPod battery pack, but I suspect it's a 2 cell Li-poly. In that case, the unit should shut off long before either cell could ever be reverse charged. But it's definately a concern when you have more than 3 or so cells, and you have something that doesn't automatically shut off when the voltage drops to a certain amount.

Re:Battery Rundown (0)

Anonymous Coward | more than 10 years ago | (#7843041)

It is bad to leave a LiIon battery at 100%. This is according to the guy that designed the charging circuitry on the PowerBook G4 when he gave a talk at Carnegie Mellon University. At least with the PowerBooks, what they do is try to keep the battery at 95% or so. In other words, they charge to 100%, then they let it self discharge, and only start giving it power again when it gets below 95%. Charging it up to 100% and then leaving it like that forever isn't good on the battery.

Re:Battery Rundown (0)

Anonymous Coward | more than 10 years ago | (#7843658)

I'd disagree concerning battery lifetime. I have Ni-Cad's that are still going strong after over 10 years. But any batterr purchased since then arn't as good. In particular, although easier to use don't Li-Ion's die out with 2 years 3 max in general ?

Ni Cad's work very well, there just impractical.

There is also rumours of deliberate sabotage, as you can no longer buy Ni-Cad's that last forever.

No, no, no, NO! (1)

SuperBanana (662181) | more than 10 years ago | (#7848459)

* Li-ion Longest life of most comercial batteries. * Much harder to develop a memory. Most people it wwould take months. * Hard on the battery if it's left full charged constantly. * Still best if fully drained and charged every time, but very forgiving.

This is almost entirely wrong.

LiIon batteries have a maximum lifespan, aroudn 500 cycles. The deeper the discharge, the more "life" you use from the battery. Like lead-acid batteries, they are NOT forgiving of complete discharge and charge cycles. They also self-discharge like Lead-acid batteries, and need a small amount of current to keep fully charged. All this is taken care of for you(see below) unless you've bought a real POS device. iPods also never "shut off" fully(on my 3rd gen iPod, I can actually hear the processor cycling if I put it up to my ear- its a periodic "bruup!" noise) and that consumes battery power. Left off a charger, your iPod WILL have very little charge left after a couple of days.

NiCad batteries- you got that all right except for "short overall life span". They have the least energy density, but last forever. I have 15 year old NiCads that are still quite serviceable. The most common death for NiCads are either getting cooked(left on a charger improperly) or developing "memory"(this is actually internal resistance) or shorting out due to crystalization.

The answer is common sense. Follow the recommendations in the manual, and don't be over-obsessive about charging it. Any device made in the last 5 years or so, especially with LiIon, has a sophisticaed battery management system. LiIon batteries --require-- very specific charge methods based on temperature, current and pack voltage so there are a lot of IC's dedicated to battery management(some/most of these chips also integrate capacity estimation, serialization, voltage+current monitoring, etc).

Re:No, no, no, NO! (1)

DAldredge (2353) | more than 10 years ago | (#7854561)

I am almost sure that what you are hearing is the hard drive, that is unless you are some sort of insect and/or a dog. :->

Re:Battery Rundown (0)

Anonymous Coward | more than 10 years ago | (#7855552)

Wrong. No battery except NiCD needs to be "deeped cycled". It's outright damaging to Lithiums.

Moderators, please mod DOWN parent! Sorry!

Battery Care (2, Informative)

m0rph3us0 (549631) | more than 9 years ago | (#7839419)

Li Ion batteries are strange you don't want to discharge them completely but you don't want to leave them topped up. My recommendation, discharge to about 50%, recharge, rinse wash repeat.

Try this site... (0)

Anonymous Coward | more than 9 years ago | (#7839473)

It's rather funny what google can turn up [google.com] ...

Re:Try this site... (-1, Flamebait)

reiggin (646111) | more than 9 years ago | (#7839980)

It's also rather sad what editors (mainly Cliff) let slide by as "News for Nerds. Stuff that matters."...

Perhaps in 2004, we should just change that to "Nerds helping Morons. Stuff that's pointless."

Re:Try this site... (1)

The Infamous Grimace (525297) | more than 10 years ago | (#7841771)

How about "Slashdot - Those in the know helping those who aren't."

Wow, what a concept. Sharing information and ideas on an open forum/platform.

Maybe someone should develop software [linux.org] using this principal.

Not everyone can be an expert on everything.

(tig)

Re:Try this site... (0)

Anonymous Coward | more than 10 years ago | (#7862104)

This probably won't get read or modded up. Blargh.

How about "Slashdot - Those in the know helping those who aren't."

One slight problem with that. 90% of people on Slashdot 'know' shit all. Of the 10% that do, they are often moderated down or ignored in avour of whoever spins the best looking bullshit.

In this respect /. is no better than the mainstream media.

Wow, what a concept. Sharing information and ideas on an open forum/platform.

Yeah it's a great concept. It's called communism. Did it work? Not really, because the implementation was crap. Slashdot is 10% ideas and information, 90% ill-informed opinion. Hell this is opinion. An open forum, where 'group mentality' of anti-MS pro-anything-open-source will definately get modded up and the opposite down? OK

Maybe someone should develop software using this principal.

Most OS stuff is developed on that principal. What happens when opinion comes into it? You get forks.
Ideas and information, great, opinion just fucks shit up.

Not everyone can be an expert on everything.

And you are not an expert on what you're talking about. Neither am I.

Noone is entitled to their opinion. They are entitled to their informed, balenced opinion.

--
Just another ill-informed moronic slashdot comment.

Some general info on rechargeable batteries (5, Informative)

BeatdownGeek (687929) | more than 9 years ago | (#7839491)

Here. [buchmann.ca]

I think the consensus is Li Ion and NiMH batteries are better kept close to full charge, and NiCads should be drained fully before recharging.

iPods use a Li-Ion battery.

Correct way to charge an iPod? (4, Funny)

Anonymous Coward | more than 9 years ago | (#7839657)

MasterCard.

Re:Correct way to charge an iPod? (2, Funny)

Anonymous Coward | more than 9 years ago | (#7839802)

Priceless!

Re:Correct way to charge an iPod? (0)

Anonymous Coward | more than 9 years ago | (#7840583)

No thanks, I steal my music.

Say, that's quite a nice iPod you've got there. Oh it is? All full of iTMS purchases? Quite nice.

OMFG LOOK OVER THERE!!! IT'S STEVE FUCKING JOBS IN THAT STARBUCKS!!

*nab*

Re:Correct way to charge an iPod? (4, Funny)

valkraider (611225) | more than 10 years ago | (#7841356)

That's not stealing. It's "Possession Infringement".

No, AmEx.... (0)

Anonymous Coward | more than 10 years ago | (#7843038)

Then, when the battery ivariably goes dead, it may have some extra protection.

The correct way to charge an iPod (1)

octover (22078) | more than 9 years ago | (#7840171)

What is the firewire cable to either my PowerBook, PowerMac, or do the wall plug that came with my 2nd generation 20 Gig iPod?

seriously though I have to say that everything I have that is Apple has been superior quality, I know some people get a bad apple from time to time, my friend had a PowerBook that just would not play nice, but overall the quality is better than other companies, its because of this pedestal they are on, that the few exceptions really stand out.

Re:The correct way to charge an iPod (1)

StarManta (692541) | more than 9 years ago | (#7840693)

....Did you bother reading the post, or just the title? People like you give the rest of us mac nerds a bad rep. *Most* of us know what we're talking about, I swear!

Re:The correct way to charge an iPod (0)

Anonymous Coward | more than 10 years ago | (#7841422)

did you bother to have a sense of humor when you read the parent comment?

Re:The correct way to charge an iPod (1)

StarManta (692541) | more than 10 years ago | (#7857855)

No. :)
He doesn't seem to be trying to be funny tho, or if he is he didnt do a particularly good job of it... Unless he was trying to make fun of us Apple types, in which case I feel I have the right to be offended...

Good Lord Jebus. . . (4, Funny)

noewun (591275) | more than 9 years ago | (#7840545)

Only on Slashdot could a thread meant to simplify things end up confusing the issue!

Speaking of which... (0)

Anonymous Coward | more than 9 years ago | (#7840607)

correct way to charge a GBA SP?

Re:Speaking of which... (1)

falcon5768 (629591) | more than 10 years ago | (#7843221)

take out the nintendo battery

toss in garbage

buy extended life battery

see Lith-Ion instructions

Different iPod problem: headphone socket (0, Offtopic)

not_cub (133206) | more than 9 years ago | (#7840731)

I have a 20gb original iPod, with the non-moving wheel. I have had it for about 6 months. Before that it belonged to a friend, who rarely used it. Recently, it has developed a problem with the headphone socket. The sound from the left headphone is intermittent. I have tried using several different pairs of headphones, but the problem remains, so it looks like it's a problem with the contact inside the iPod rather than the headphones. I was wondering if any other slashdotters have had this problem, and if so, if you have found a solution.

Thanks,
not_cub

Re:Different iPod problem: headphone socket (1)

ZackSchil (560462) | more than 10 years ago | (#7841506)

You could open up the iPod as per the instructions to replace the battery and bend the contact on the inside of the jack back out. (In? at any rate, the way towards the headphone male plug.)

Re:Different iPod problem: headphone socket (0)

Anonymous Coward | more than 10 years ago | (#7852139)

I had the same problem with my Apple Remote. If the connection is anything like that then you will need to resoder it to the main board. Look for the loose contact "foot" when you GENTLE wiggle the head phone plug front to back, in reference to the display. You should be able to hear when the "foot" makes contact if you have on the plugged in head phones, and see one "foot" move slight away form the main board. Warning: be careful not to solder two "feet" together and to solder the right no left ... a correct one. good luck

Re:Different iPod problem: headphone socket (0)

Anonymous Coward | more than 10 years ago | (#7861222)

yes I had this happen. I just took it into the Apple store and went to the guiness bar and they replaced it on the spot.

fine if kept charged (1, Interesting)

Anonymous Coward | more than 10 years ago | (#7840773)

I've kept my rev A 10 GB ipod plugged in constantly for a couple of years--it's my main source of music at home and is plugged into my stereo at almost all times. But, on recent international flights, it has given me a solid 8 hours of music. I don't know why there is so much complaining about bad battery life.

This is a bullshit answer... (0, Redundant)

dnahelix (598670) | more than 10 years ago | (#7840954)

Q: Why doesn't Apple make the battery easily replaceable? Or use different batteries, like AA? A: Because if they did either, the size of the batteries and/or the access panels and mechanisms required to access the battery would make the unit significantly larger than it is, likely by several millimeters in thickness at a minimum, and would also affect other dimensions, as well as weight. It was an engineering decision to use an integrated battery; if it were not integrated, the unit would not have the small, sleek form factor that makes it so attractive in the first place. Additionally, the iPod's battery is indeed replaceable, as has been discussed above.

Excellent battery resource... (4, Informative)

Steve Cowan (525271) | more than 10 years ago | (#7841042)

Where I work I need to know a lot about rechargeable batteries. My impression of Li-ion / Li-Polymer is that they don't mind having a "float charge" at all... what the previous posts fail to mention is that for safety reasons, all Li-based chargers are intelligent enough to not overcharge the batteries (except cheap offshore chargers and car adapters, but you won't likely find anything like that for your ipod). In other words, I believe it is safe to leave an ipod plugged in indefinitely.

We picked up a battery analyzer from Cadex [cadex.com] , which is really cool, and I use it every day.

But the really cool thing is that the charger came with a little paperback book called "Batteries in a Portable World", which offers a lot of insight into varying battery chemistries, even though it is sort of a pitch for Cadex products.

Nevertheless there is an online version of this book [buchmann.ca] . Go to chapter 2 and read up! There is some very valuable battery maintenance info in there -- if you own a single rechargeable battery it is a very good read. (The website asks for your email address, but you can probably just use a fake one).

Re:Excellent battery resource... (4, Interesting)

gothzilla (676407) | more than 10 years ago | (#7841182)

I used to work at Radio Shack and did a very informal survey. Every time someone came in to buy a new battery for their cordless phone I asked how they cared for the phone and how long the battery lasted. In general, the more it was left on the charger, the shorter the life span. I broke down phone care into 3 groups: 1) Phone left on charger when not used. Battery lifespan was about 1 to 1 1/2 years. 2) Tried to keep phone on charger but forgot a lot. Lifespan about 2-3 years. 3) Kept phone off charger till the little light came on. Life span was 5 to 8 years. These are pretty cheap batteries but the responses were pretty consistent. I also talked to people who bought standard rechargable batteries and rechargables for RC planes and cars. They answers and life spans matched pretty well.

Re:Excellent battery resource... (1)

gerardrj (207690) | more than 10 years ago | (#7843142)

Your survey is very accurate for the type of batteries on most cordless phones. NiCad batteries do indeed last longer when allowed to mostly discharge then be recharged.

Lithium based batteries (like the one in the iPod) tend to last longer when kept more fully charged, much like lead acid batteries in cars.

Re:Excellent battery resource... (1)

Naffer (720686) | more than 10 years ago | (#7847865)

Actually, I'm pretty sure that most if not all LiION batteries have a built in circuit that prevents serious overcharging or serious discharging. The danger is not from faulty chargers, but from defective battery packs or ones who's protection circuit may have failed.

Re:Excellent battery resource... (1)

Steve Cowan (525271) | more than 10 years ago | (#7850402)

That sounds right. It would certainly explain why offboard analyzers such as the Cadex unit I referred to seems to have trouble reading Li-ion batteries, because there is always a little circuit board in the battery pack with an IC on it... it probably fools the analyzer a lot of the time because it prevents it from seeing the cells directly.

Another interesting factoid: Lithium based cells are 3.6 volts, while NiCD and NiMH are 1.2 volts. Why ask why? :)

Cheers -- happy new year.

iPodLounge tips for recharging batteries (1)

switcha (551514) | more than 10 years ago | (#7841292)

here [ipodlounge.com]

How about just go here. (1, Informative)

Anonymous Coward | more than 10 years ago | (#7842592)

You could go here:
http://ipodbatteryfaq.com/

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

Come on guys.

Mac OS X Hints chimes in (4, Informative)

Mikey-San (582838) | more than 10 years ago | (#7843021)

This is a GREAT summary of lithium-ion battery tech, as found on Mac OS X Hints:

http://www.macosxhints.com/article.php?story=200 30 314081843218

Don't forget to check out the source material to which the article links, as well. Good stuff.

Interesting reading. (4, Informative)

gklinger (571901) | more than 10 years ago | (#7843150)

Check out the Battery University [batteryuniversity.com] for the answers to all your battery questions.

Way to go (3, Funny)

EvlG (24576) | more than 10 years ago | (#7843709)

Ask Slashdot, and you get 1000 geeks posting conflicting answers they "know" to be correct, all with conflicting "supporting evidence" from people that "know" it is correct.

Way to go.

Don't fuss about it. Battery life is limited. (4, Interesting)

dpbsmith (263124) | more than 10 years ago | (#7844385)

I've listened to all sorts of advice and have conducted limited experiments.

I believe the great unstated truth is that rechargeable batteries just plain have a limited life.

In fact, the lifetime on any one particular cell seems to be subject to a great deal of variation. For about ten years I tried to power all my AA, C, and D-cell-powered devices from rechargeable Nicads, and even when usage and recharging patterns were similar, some batteries _bought at the same time in the package_ might died after a year and a half, while others would be going strong after four years. I suspect this variation is one reason why manufacturers are so vague about lifetimes, and also contributes to peoples' superstitions (as they try to correlate the random behavior of individual cells with what they did to them.)

People who try to share rechargeable devices tend to bully each other and try to impose their personal superstitions about it ("I TOLD you not to keep it on the charger, Mabel!"), and companies who do not wish to replace dead batteries certainly are inclined to reinforce this. If I were a support person and someone phoned me with a battery issue, I would certainly suggest that they discharge the battery fully and recharge it. Why not? It would get them off the phone, and it MIGHT work, and when they called back to say it didn't it would be someone else's problem.

As for leaving batteries in the charger, at some point you have to assume that the people who make the batteries and the charger know what they're doing, and that the charger is smart enough not to deliver life-threatening quantities of charge to a fully charged battery. Certainly this should be true in these days where the chargers and batteries have microchips in them.

So I say, don't kick yourself over it. Accept the fact that rechargeable batteries are a) damn expensive, and b) only last a couple of years. Yes, it sucks, but lots of things do.

"Rechargeable" batteries sound as if they should last forever. So did "permanent needles" (ha! anyone else remember THOSE?), permanent waves, and permanent-press clothing.

Re:Don't fuss about it. Battery life is limited. (1)

macostech (181494) | more than 10 years ago | (#7851087)

>I believe the great unstated truth is that rechargeable batteries just plain have a limited life.

As opposed to what!!!??? Do NON-rechargeable batteries have an infinite (or even indefinite) life span?

My own experience (3, Insightful)

jlower (174474) | more than 10 years ago | (#7846351)

I'm no battery expert, I don't even play one on the internet, but I can relate my own experience as a true early adopter.

I've got a 5 gig iPod purchased in Nov 2001. I use it at least 6 hours+ every day at work. I rarely use it on weekends. When it's not in use, it is on the charger (the AC adaptor, not hooked to my computer) - always, no exceptions.

It's now 26 months old and as far as I can tell the battery is almost as good as new.

So, my secret to success in a nutshell:
- almost never run it all the way down
- use it on a very regular basis
- always on the charger when not in use

Of course, YMMV but this has worked extremely well for me.

Number of Cycles (1)

nilspace (676196) | more than 10 years ago | (#7859536)

Something I heard awhile ago, but haven't seen any discussion of is the importance of the *number* of charge/discharge cycles. Li-Ion batteries are limited to about 1000 charge/discharge cycles. A cycle is defined as a switch between charging up and then discharging or vice-versa. Therefore, when you plug in your device to charge, -1 cycle. If you "use up" your cycles in 2 months by continually plugging & unplugging, so be it. Or over 3 years, same number of cycles. This may explain the "left in charger" syndrome if a charge deactivates charging when it's topped off, but then restarts when the battery dips below 100%. This is like a bouncing affect and burns away your charge/discharge cycles. Therefore, for my devices I attempt to limit the times I plug & unplug them. With laptops I go so far as to remove the battery before plugging it into the wall just to ensure that it isn't used if I know I'm going to be working at one place for awhile. It may just be another myth, but I have 2 laptops, 1 that is 3.5 yrs old and another that is 1.5 yrs old and both are holding their charges fine! (iPod going on 1.5 years too)
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