How to NOT kill the battery?

Posted:
in iPod + iTunes + AppleTV edited January 2014
CNet suggests not using the battery until it completely runs out. Is this true? Why? Any other suggestions?

Comments

  • Reply 1 of 20
    Quote:

    Originally posted by chocolatedude

    CNet suggests not using the battery until it completely runs out. Is this true? Why? Any other suggestions?



    Tips and tricks to get the most out of your iPod's battery
  • Reply 2 of 20
    chuckerchucker Posts: 5,089member
    If you don't plan on using your iPod for a while, you can always put it in a freezer.



    Other than that, it doesn't matter much whether you leave it charged or half-charged or empty; it'll continuously lose capacity regardless.
  • Reply 3 of 20
    xoolxool Posts: 2,460member
    Just like laptops, your iPod's battery gets dinged every time you charge it. By waiting 'til the battery is depleted you are basically extended the time between charges.



    Compare these scenarios: (1) You connect your iPod every night before going to bed and sync/charge it overnight. (2) You connect your iPod every 3 days or so when the battery is getting low.



    So over the course of a year you'd charge it approximately 300 times versus 100 times. The iPod in scenario two would have a greater maximum capacity and the iPod in scenario one would have a more degraded battery.



    It is for this reason that I suggest you be realistic with your iPod. Do you really need that latest podcast or could you wait one more day? You can always sync it more often but you can't revive the battery without replacing it.



    Now if you're on the multiple charge per day cycle, keep it up and buy the iPod AppleCare. That way you can get the battery replaced for free once or twice within the first two years. By year three you'd want a new iPod anyhow.
  • Reply 4 of 20
    xoolxool Posts: 2,460member
    Quote:

    Originally posted by tonton

    Wowowow! That's such a BAD idea. Crazy bad. CON.DEN.SA.TION will kill your iPod smackfast(R).



    I would wager that the freezer won't play nice with the LCD screen either.
  • Reply 5 of 20
    chuckerchucker Posts: 5,089member
    Quote:

    Originally posted by tonton

    Wowowow! That's such a BAD idea. Crazy bad. CON.DEN.SA.TION will kill your iPod smackfast(R).



    Someone missed out on my sarcasm.
  • Reply 6 of 20
    Quote:

    Originally posted by Xool

    Just like laptops, your iPod's battery gets dinged every time you charge it. By waiting 'til the battery is depleted you are basically extended the time between charges.



    Compare these scenarios: (1) You connect your iPod every night before going to bed and sync/charge it overnight. (2) You connect your iPod every 3 days or so when the battery is getting low.



    So over the course of a year you'd charge it approximately 300 times versus 100 times. The iPod in scenario two would have a greater maximum capacity and the iPod in scenario one would have a more degraded battery.



    It is for this reason that I suggest you be realistic with your iPod. Do you really need that latest podcast or could you wait one more day? You can always sync it more often but you can't revive the battery without replacing it.



    Now if you're on the multiple charge per day cycle, keep it up and buy the iPod AppleCare. That way you can get the battery replaced for free once or twice within the first two years. By year three you'd want a new iPod anyhow.




    All of that makes sense and it's what I orginially thought, but then why does CNet advocate not letting it drop to no power?
  • Reply 7 of 20
    telomartelomar Posts: 1,804member
    Ok there is so much bad advice in this thread.



    Big 3 if you want longevity out of a Lithium battery. Keep it out of heat, don't store it or leave it with a low charge (manufacturers store them at around half charge if you're wondering and there are reasons for that), avoid deep discharges of the battery and never drain it fully (this is hard to do by the way as it usually switches off before then to protect itself), it doesn't hurt to charge a Lithium battery often and optimally you'd love to leave the power floating around the midranges.



    After work I'll explain the reasons behind all that.
  • Reply 8 of 20
    xoolxool Posts: 2,460member
    Quote:

    Originally posted by chocolatedude

    All of that makes sense and it's what I orginially thought, but then why does CNet advocate not letting it drop to no power?



    I don't know the full details but it is sort of like a car battery in that if it is drained completely it may lose the ability to hold a charge. For this reason the iPod auto shuts off when the battery gets very low.



    I recommend going as long as possible between charges but don't go crazy about it.



    Temperature also impacts battery performance but I don't know specifics or the technical details. I'm looking forward to Telomar's info.
  • Reply 9 of 20
    telomartelomar Posts: 1,804member
    The first thing worth mentioning about Li batteries is they come in quite a number of different types depending on the and each one displays slightly different characteristics so how you care for one type does differ slightly to another. For instance some Li-Ion batteries respond quite poorly to temperatures in excess of 40 degrees C and others can handle quite wide temperature ranges. In practice you'll rarely be able to tell the exact type so here's some general info aimed at what you'll see mainly in CE devices and laptops. It's worth mentioning these batteries are still undergoing heavy development and improvement.



    Firstly, Lithium batteries start to die the minute they are produced, whether you use them or not. This is caused by the destruction of the positive electrode through oxidation and there's sweet nothing you can do to stop that only slow it. Add to that each time you charge them the electrode is actually deteriorated so you do have a limited number of cycles. Unlike older NiMH or NiCd batteries though whether you cycle fully or not doesn't matter. Most of the aging effects that occur in Lithium batteries is also true in NiCd and NiMH batteries it is just they are a bit more susceptible and tend to do it faster.



    That said they do possess some very nice advantages that make it worthwhile, they produce higher voltages and hold more energy than other battery types and Li-Polymer especially are far more moldable and theoretically could store more energy still (they don't yet to my knowledge). It's also worth noting true Li-Polymer batteries don't tend to be used for CE because they really need to function over 60 degrees C to get a reasonable discharge rate so generally a hybrid is used.



    So what are the key things. Basically the key problem with Lithium batteries is oxidation. As the electrode oxidises the internal resistance increases your ability to deliver current drops, which in turn drops the run time of the battery so most battery care should be around how do you reduce the rate of oxidation.



    If ever you get the chance to observe voltage change in a bettery on a digital device what you'll tend to find is they draw power in bursts so you suddenly see voltage drop then climb back up. CE devices cut off at a set voltage, usually 3V, and as resistance increases the drop that occurs with each power draw increases. So a new battery might drop 0.2V under load, an older one with higher resistance might drop 0.6V. This is quite often you'll do something and the device will shut off but you can turn it back on and it'll sit idle for a while. It's due to those peak power draws.



    So how to care for it. Firstly, avoid high temperatures. Because the oxidation occurs from the minute it leaves the factory if you store it in hot areas you just accelerate it. Every 10 degrees C doubles the rate. Manufacturers aim for around 15 degrees as it is easily obtainable. Don't leave it in overly hot areas is all I suggest. If you leave it in a hot car, expect the battery life to shorten significantly.



    Next try to avoid full discharge. Certain damaging reactions increase at low voltages that can shorten a battery's life. Again it depends on battery type but try to only drop battery to about 20% where possible then recharge it.



    So why do they fail? I'll do this like a FAQ for ease.



    Q. My battery won't charge anymore. Why?

    A. It has been discharged too far. At low voltages certain dangerous side reactions occur so a protection circuit seals the battery. Once that has happened you won't be able to apply a charge to that battery again.



    This usually occurs from being stored at a low charge. The battery will turn itself off early but then naturally self-discharges with time and there's a point at which to protect the user it will form a shunt and stop use completely. Low voltage batteries actually require charging with lower current if you're wondering or else they short circuit and over heat, which can cause Lithium batteries to explode or catch fire. If the protection fails that's why you hear such reports sometimes.



    Q. I charge my battery but it runs out of charge quickly. Why?

    A. For whatever reason the battery electrode has oxidised. Usually it's age, sometimes it's mishandling and other times it is just poor manufacture and storage.



    Q. I won't use my battery for a while. How should I store it?

    A. 15 degrees and 40% charge is what manufacturers suggest (go slightly higher rather than lower). This is why you'll find your battery should have some charge when first used. Low temp lowers the rate of oxidation, midrange voltages prevent certain reactions occuring and allow for some self-discharge.



    Q. My battery heats up when charging, is this normal?

    A. To some extent yes although in an ideal charger the battery keeps cool during charge. Excess heat can be indicative of an overcharge however. It's hard to tell. If in doubt stop charging for a while until it cools. You won't hurt a lithium battery by undercharging it.



    Q. My battery exploded on me and I am horribly disfigured.

    A. Well the battery's explosion probably made you look prettier then If your protection circuitry fails and you overcharge a Lithium battery it forms metallic lithium, this is highly reactive and you tend to get runaway reactions that ultimately result in heat and pressure. Same thing happens if the battery short circuits for some reason. Also the electrolytes aren't always stable. Quality control matters in these batteries.



    Don't buy cheap batteries.



    Q. My battery has survived 10 years and I did nothing special. Hah.

    A. Yeah I have a battery that has survived that long. Not really sure how.



    Q. You missed stuff, tell me more answers.

    A. Sorry been a long couple of days. Ask and I will



    Edit: Q. How does temperature effect battery performance?

    A. It does actually improve the performance of the battery because it lowers the internal resistance. The downside is it will shorten the battery's life.
  • Reply 10 of 20
    maimezvousmaimezvous Posts: 802member
    Quote:

    Originally posted by Telomar

    The first thing worth mentioning about Li batteries ... The downside is it will shorten the battery's life.



    Wow, that was amazing, and incredibly informative and useful. Thank you for saving me time and money. I wish I would have known this stuff before I killed my 4g iPod mini's battery.
  • Reply 11 of 20
    That's some great info, thanks.



    If I plug my iPod into my computer as I do once a week to update podcasts (about 25 minutes), and then I plug it directly into the power adapter into an outlet to charge it as soon as I take it out of my computer, does this count as 1 or 2 charges?



    Thanks.
  • Reply 12 of 20
    telomartelomar Posts: 1,804member
    Only counts as 1. Really each cycle is draining it 80% or more roughly.
  • Reply 13 of 20
    Quote:

    Originally posted by Telomar

    Only counts as 1. Really each cycle is draining it 80% or more roughly.



    Great, thanks.
  • Reply 14 of 20
    if you let it do that...the you will calibrate the battery making it work longer
  • Reply 15 of 20
    Quote:

    Originally posted by Danired18

    if you let it do that...the you will calibrate the battery making it work longer



    Wasn't it discussed in this thread that lithium ion batteries do not have a charge memory. Therefore it doesn't matter what you do to the battery. Also that Li ion batteries have a set number of charge cycles and that is what matters?
  • Reply 16 of 20
    telomartelomar Posts: 1,804member
    Lithium batteries don't require calibration. They have no memory effect and remaining power is judged by output voltage. That's why it'll jump a bit. That said it's suggested that the first time you fully charge the battery even though it has some charge.
  • Reply 17 of 20
    Quote:

    Originally posted by Telomar

    Only counts as 1. Really each cycle is draining it 80% or more roughly.



    This may be a stupid question, but if I keep it always above 20%, does this mean that it will never count as being charged?
  • Reply 18 of 20
    telomartelomar Posts: 1,804member
    Unfortunately not. I perhaps phrased that badly. It's life is still ticking away just not as fast. There's just a notable increase in electrode degradation rate at lower charges.



    If you want to count cycles then count cumulative discharges. For instance 2 60% discharges would count as roughly 1 while 1 80% charge would be the same. The reason being at low charges you get side reactions within the battery that don't reverse under normal charging so you end up losing battery life.
  • Reply 19 of 20
    Quote:

    Originally posted by Telomar

    Unfortunately not. I perhaps phrased that badly. It's life is still ticking away just not as fast. There's just a notable increase in electrode degradation rate at lower charges.



    If you want to count cycles then count cumulative discharges. For instance 2 60% discharges would count as roughly 1 while 1 80% charge would be the same. The reason being at low charges you get side reactions within the battery that don't reverse under normal charging so you end up losing battery life.




    Thanks!
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