Short battery life

Discussion in 'Macintosh Computers' started by Mala, Jan 11, 2005.

  1. Mala macrumors 6502

    Joined:
    Nov 19, 2003
    #1
    I have a one-year-old G4 15" PowerBook. I generally use it plugged in, but have recently had to use it with the battery only. Unfortunately, the battery only lasts about half an hour to three-quarters of an hour. Is there a way to fix this?
     
  2. Applespider macrumors G4

    Applespider

    Joined:
    Jan 20, 2004
    Location:
    looking through rose-tinted spectacles...
    #2
    Have you calibrated the battery regularly? Recently?

    What are you running when you're on battery only? Really processor intensive tasks or general surfing? Are your energy saving preferences set to 'longest battery life' when on battery power? Do you turn off Bluetooth/Airport if you don't need them? Do you turn your screen brightness down?

    My PB is a year old. I run it on 'longest battery life' on a relatively low screen brightness (2 or 3 if I can get away with it). With Bluetooth off but Airport on, I get about 2 hr 45.

    There is a terminal command you can use to find out your battery capacity that I can't recall but I'm sure you could search for or someone could help you with.
     
  3. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #3
    Buy a nwe battery? If you have been using it on mains power without using the battery for a long time then the battery is probably not in great state. Apple have a page on battery care here.

    I had this happen with my 15" as well and am being more carefull to use the new battery as a battery more often.
     
  4. varmit macrumors 68000

    varmit

    Joined:
    Aug 5, 2003
    #4
    yeah, any laptop you have to take care of the battery. In fact, any device that has a rechargeable battery you need to take care of. Discharge the battery every so often so that this doesn't happen. I did this with my iBook, only could get an hour out of it. Then I got a new battery, now I can go for 6 hours sometimes.
     
  5. Logik macrumors 6502a

    Joined:
    Apr 24, 2004
    #5
    Turn the brightness on the screen down to 1 or 2 notches.. harder to read at first but you get used to it. it adds a lot of life... i get about 3 hours 45 minutes on my 1.33ghz Rev C. 15" powerbook. i do web browsing, word processing and chatting online with it and it lasts about 3 hours and 45 minutes... a definite improvement over your barely 2 hours... i also have bluetooth turned off when i'm on battery power, airport is on. if i turn airport off i run around 4 hours and 15 minutes :p oh and the laptop is about 8-9 months old.. got it in march
     
  6. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #6
    Sometimes, but not always, you can rehabilitate an undernourished battery like that, by using it on battery power with deep-discharge cycles repeatedly. That is, charge it, run it empty (till the computer sleeps), let it charge again, and do this several times. Sometimes the battery life will improve as a result of this.

    And eep...I suppose I need to go play with my Powershot S50...it's been sitting in the drawer for a while! :eek: Don't want the battery to die! :(
     
  7. crenz macrumors 6502a

    crenz

    Joined:
    Jul 3, 2003
    Location:
    Shanghai, China
    #7
    It used to be longer for me, but it is about the same now (1.25 GHz, 15" PB here; btw. the 1.33 GHz one has a bigger battery) after the recent system updates :(
     
  8. MacNeXT macrumors 6502

    Joined:
    Jun 21, 2004
    #8
    Do NOT fully decharge Lithium-Ion batteries! Deep-cycling is intended for NiMH and NiCd batteries. Li-ion batteries lose capacity every time they're decharged.

    They also lose capacity over time, about 15 to 20% a year, that's inevitable. When the battery is often kept in warm environments, this percentage is higher. This percentage also depends on the charge. The higher they're charged, the more capacity they lose. Therefore, when Li-ion batteries aren't discharged often (or kept in storage), it's best to have them charged at around 40%.

    Therefore keeping it charged all the time (eg when you always connect your 'book to net power), is not optimal!

    BTW, when storing a Li-ion battery, keep it in a refridgerator!
     
  9. Mala thread starter macrumors 6502

    Joined:
    Nov 19, 2003
    #9
    MacNext, if I shouldn't fully decharge the battery, should i do all the other stuff?

    Setting the brightness low isn't an option; my glasses prescription is -10 on both eyes!

    What's all this about recalibrating - does this apply to a Lithium-Ion battery, please?

    I don't know what's battery-intensive use and what isn't. Mostly I'm using Firefox, Eudora and Word, but sometimes I'm copying CDs, etc.

    Thanks for all the good answers; please continue to educate me. Off to read the Apple batteries advice now.

    If I do have to buy a new battery (eep), where should I get it, and how much should it cost?
     
  10. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #10
    AppleStore (if there is one handy, or online) about £90 in the UK. Note you get the higher capacity battery from a new PowerBook so you should see excellent battery life.
     
  11. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #11
    Well, if the current capacity is half an hour.... :rolleyes: This is the way I've used every lithium ion product I've owned, pretty much, and I've had good results. As for at least occasionally deep-discharging the iBook/PB battery, even Apple's website specifically tells you to do that.
     
  12. MacNeXT macrumors 6502

    Joined:
    Jun 21, 2004
    #12
  13. Mala thread starter macrumors 6502

    Joined:
    Nov 19, 2003
    #13
    Many thanks. I ran the battery right down, then actually took it out for around 20 minutes. Then I put it back in and plugged in the power, and went to System Preferences, where I changed the Energy Saving specs to use minimum processor power. It's now lasting three hours or more.
     

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