Will your battery last longer if you do BIGGER charges?

Discussion in 'iPad' started by Piggie, Jul 9, 2010.

  1. Piggie macrumors 604

    Piggie

    Joined:
    Feb 23, 2010
    #1
    Didn't Apple say a charge cycle is when you charge it and the battery would last so many cycles?

    So, would you get a much better battery life if you generally run it down to 10% (for example) then charge it right back up to full again, as opposed to people why keep topping it up when it runs down to 80% (for example)

    Or those who keep charging it every night when it's no where near empty?
     
  2. Geoff. macrumors 6502

    Geoff.

    Joined:
    Jun 1, 2009
    #2
    It's good to calibrate it every month or so.

    This is where you run it down from 100% all the way down to 0 and charge it up again.

    On my MacBook which is a year old my battery capacity is better than what it was when I got it and what I do is use it until it gets to around 5 percent and charge it up, I do the same on my iPhone so it's hard to know.
     
  3. JohnSFO macrumors regular

    JohnSFO

    Joined:
    Jun 10, 2010
    #3
    For whatever reason it's very difficult to get a definitive answer on this subject. It's been ongoing since the first battery operated Apple device came out. Some claim that battery technology has changed over time and it's not necessary to use up a full charge before recharging, while others hold that it is still the best way to treat the battery. Apple tells us to charge down close to 0 and back up to 100 at least once a month. I try to use up a full charge before recharging because it makes me feel like I'm getting the most of that cycle. It's not like I can't go without the device for 4 hours while it charges back up to 100%. I've been charging overnight (but only if it's below 10%) quite regularly too. It's nice to wake up to fresh new battery cycle. :)
     
  4. mklnk macrumors regular

    Joined:
    Apr 14, 2010
    #4
    I'm pretty sure running the battery to 50%, then charging back to full is half of a charge cycle.
     
  5. philip in al macrumors regular

    Joined:
    Jun 23, 2010
    #5
    "Lithium-ion is a very clean system and does not need priming as nickel-based batteries do. The 1st charge is no different to the 5th or the 50th charge. Stickers instructing to charge the battery for 8 hours or more for the first time may be a leftover from the nickel battery days."

    http://www.batteryuniversity.com/partone-12.htm
     
  6. Angryipadguy macrumors regular

    Joined:
    Jun 27, 2010
    #7
    Li-ion cells don't like to be totally drained then charged to full capacity. They will last much longer if you keep them topped up. They do not get a memory affect so discharges are never needed. I have had over 1800 charges from good quality li-ion cells what was abused. You should easy see 10 years of good runtime from the battery in the iPad.
     
  7. ntrigue macrumors 68040

    ntrigue

    Joined:
    Jul 30, 2007
    #8
    Once a month let iPhone dies completely. Then leave plugged-in for at least five hours.

    That being said, daily advice is to never go below 20%. Do not charge unless it's below 80%.
     
  8. Angryipadguy macrumors regular

    Joined:
    Jun 27, 2010
    #9
    That's the worst. Possible thing to do with a li-ion cell. They do not like to be drained below their cut off voltage of around 3.0v. If you make the cells drop below that voltage then you won't be able to reverse the damage and you will lose cell capacity. It's a good idea to not let the cell get lower than 30% of it's capacity to maintain it's life. They do not need to be discharged. I repeat do not need to be discharged. This is the case for nicd and nimh cells though of which nicds need to be discharged to there cut off voltage almost after every charge. Where as nimh cells need to be discharged around every 10 charges to cut off voltage.
     
  9. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #10
    Why does Apple recommend this then?

    Use Your iPad Regularly

    For proper reporting of the battery’s state of charge, be sure to go through at least one charge cycle per month (charging the battery to 100% and then completely running it down).


    from http://www.apple.com/batteries/ipad.html

    It even recommends it for its notebooks.
     
  10. JohnSFO macrumors regular

    JohnSFO

    Joined:
    Jun 10, 2010
    #11
    Like I said ^^^ ;)
     
  11. dmelgar macrumors 68000

    Joined:
    Apr 29, 2005
    #12
    Partially not true.
    Li-ion batteries can be ruined if they are totally discharged. However, all li-ion batteries have smart charge circuits associated with them that do not allow them to get completely discharged. When the devices says the battery is at 0%, it is not really. It cuts it off early to protect the battery.

    It is also harmful to a li-ion battery to be fully charged and hot. It is best to maintain a li-ion battery around 50%. But thats not realistic, so just use it and don't worry about it.
     
  12. Angryipadguy macrumors regular

    Joined:
    Jun 27, 2010
    #13
    Most electronics that use li-ion cells do not have a low voltage cut off. If the iPad does then Great go ahead and discharge till the iPad cuts of then you will be fine and won't harm the battery. I run high power rc boats and cars and have always had to add after market circuits that beep and cut power to warm me I'm close to low voltage cut off point. I have ruined many a cell phone battery from letting it sit dead for too long.
     
  13. dmelgar macrumors 68000

    Joined:
    Apr 29, 2005
    #14
    Computer equipment definitely has a low voltage cutoff. Includes cell phones, iPhone, iPad, laptops.

    You can most definitely still kill the battery but discharing as far as it will go, then store the empty battery. Li-ion batteries will lose power when not used. They do so very slowly compared to NiMh batteries but they do it none the less. Eventually the battery becomes truly discharged and complete cell failure results.
     
  14. JohnSFO macrumors regular

    JohnSFO

    Joined:
    Jun 10, 2010
    #15
    So you're saying that it's okay to let the iPad drop to 0%, but that you shouldn't leave it that low. Start charging once it runs out, right? I've only had the iPad turn off once because the battery "ran out." Is that the "low voltage cutoff" moment?
     
  15. Angryipadguy macrumors regular

    Joined:
    Jun 27, 2010
    #16
    Hopefully it is yes. It's har to tell unless you test each cell to confirm it's not dropping below it's cut off point. It would be crazy if they didn't fit a low voltage cut off onto the iPad but I have seen many electronics that have not had it and taken batter below the cut off point and ruined the cells. The more voltage they loss below cut off voltage the more mah you will lose from the cell.
     
  16. phoobo macrumors regular

    Joined:
    Sep 13, 2008
    #17
    Read the fine print

    Notice that this calibration serves only to make the "charged %" readout more accurate. It has nothing to do with extending the life of the battery.

    50% seems to be the consensus -- but it's also true that these batteries will lose their capacity over time whether you use them or not. So probably not worth worrying about.

    For further info look through the archives of www.dansdata.com
     
  17. Piggie thread starter macrumors 604

    Piggie

    Joined:
    Feb 23, 2010
    #18
    I always understood it was heat and constant charging that damaged the long term life of ANY battery.

    That's why they say if you want to make the battery in a laptop last and you are using it at home, charge it fully, let it run down to about 75% to 80% take it out, wrap in plastic and stick in fridge.

    If you run the laptop on the mains most of the time, you are keeping the battery warm and constantly charging it which is not good for it.

    I know Apple say to run down to nothing and recharge once a month.

    I was wondering what's best to do between times.

    Keep topping up once it gets a bit low, or just let run down to say 20% (you get the warning) then charge up.

    I tend to let it get down to 15 or 20% then charge up, that way I only charge up perhaps a couple of times a week.
     
  18. ntrigue macrumors 68040

    ntrigue

    Joined:
    Jul 30, 2007
    #19
    Thank you for offering an RC car perspective but you are largely incorrect when it comes to modern Li-Ion technology in the mobile/PC industry.

    www.batteryuniversity.com
     
  19. Angryipadguy macrumors regular

    Joined:
    Jun 27, 2010
    #20
    Lol perhaps take a look at the batteries range in rc before you think it's dated. Li-ion has been about in the hobby world far before it was ever used on cellphones and laptops. I have li-ion cells over 8 years old that are still running to this day but mah is a little low compared to my modern cells. Try and get your cell phone or laptop cells to last that long! I was using $500 chargers though to charge these cells and not some $5 plug in the wall adaptor. Like comes with most electronics.
     
  20. TheDoty macrumors newbie

    TheDoty

    Joined:
    Jul 8, 2010
    Location:
    Brooklyn
    #21
    I've ruined Li-ion batteries in laptops by repeatedly running them down (thank you, Linux with broken power save features, ha!). Each time I drained it fully I'd lose something like 3% of full capacity.

    I've had great success with apple products by following the normal advice for Li-ion cells (which looks like it might conflict with Apple, oh well) and never running them down.
     
  21. JohnSFO macrumors regular

    JohnSFO

    Joined:
    Jun 10, 2010
    #22
    Well it's always nice to get a fresh perspective. From the helpful posts here I've learned to stop draining my battery down so low. I think I'll start charging it up when the first warning (20%) arrives. I don't think I can be bothered with trying to maintain 50% though. At that point I'd be obsessing and not enjoying the device - and as a Virgo I don't need anymore obsessions in my life! :p
     
  22. toxic macrumors 68000

    Joined:
    Nov 9, 2008
    #23
    for long-term storage, the battery should be at about 40%. in normal use, it doesn't matter. you just need to run it down until it shuts itself down (or close to it) every now and then to keep the battery meter calibrated.

    on a laptop, if you rarely unplug it from the AC adapter, you just need to unplug it every now and then to keep the battery properly conditioned.
     
  23. Angryipadguy macrumors regular

    Joined:
    Jun 27, 2010
    #24
    Li-ion cells do not have a memory effect! So no need to condition battery. Yes they may show a digital mem affect but this does mean the battery need to be discharged. It means that the equipment used to montitor the batteries condition needs a baseline to work from and a fuel discharge may be needed to make sure the equipment is reading the batteries condition correctly. I have never come across this but it is heard off. As an example when you leave laptop battery connected all the time and laptop still says battery is flat even though it will last all day. Again very rarely seen but it does happen.
     

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