Does using a 85W Magsafe on MBP 13.3 reduce battery life?

Discussion in 'MacBook Air, MacBook & MacBook Pro' started by johnwee, Sep 6, 2009.

  1. johnwee

    johnwee Member

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    A buyer is asking me if using a Apple 85W MagSafe on a Mac Book Pro 13.3 reduce the the battery life. Mac Book Pro 13.3 is being sold with a 60W MagSafe.
     
  2. bhoyetjumpay

    bhoyetjumpay Well-Known Member

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    i think its too risky, instead to prolong the battery life, it will shorten, just imagine you put an extra power to your battery

    apple specified that 60w and 85w is for macbook and macbook pro respectively

    anyway, 15" 2.53 macbook pro uses 60w and the rest uses 85w magsafe
     
  3. mark_17

    mark_17 Active Member

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    imo no.. afaik it will reduce your charge time of the battery to full since you'll be using a charger with higher wattage.
     
  4. Shinrai

    Shinrai Guest

    I'm not sure but if the voltage is the same, there should be no problem. It's the extra voltage that usually destroys stuff (think 110v vs 220v).

    The Mac should also stop charging if it's full batt already so it won't be overcharged. I think the confusion arises in that the MBP 13" has a 60W MB Magsafe even though it's a Pro.
     
  5. mark_17

    mark_17 Active Member

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    not really... ibook g4 where shipped with using 45w ac adapters while powerbook g4 15" & 17" where shipped with 65w ac adapters because it needs more power and the 45w is not enough... eventually apple discontinued the 45w since you can use the 65w on the ibook g4 just fine.

    what you don't want to do is use under-powered ac adapter on your unit.. it makes the ac adapter and battery heat-up faster and hotter than usual which will definitely shorten the life of both.
     
  6. madmax168

    madmax168 Active Member

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    it should not affect the battery life but if you were to use a 60W charger on a Macbook Pro which requires the 85W charger, you probably would burn out the charger.
     
  7. du1jec

    du1jec Member

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    Charging is regulated by the laptop and not the charger. Using an 85w on a 13 in will result in a cooler running power supply. Charging times will not shorten nor will the laptop experience any adverse effects.

    Only your pocket book will suffer any negative effects since an 85w costs more than the 60w which is all you really need for a 13 in.

    Jojo
     
  8. extremeshot

    extremeshot PhilMUG Addict Member
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    I wouldn't try it on my 13" MBP but better ask Apple Authorized Service Centers just to be sure. But I bet, even the Service Centers will say it's not safe based on these (see below) -- Look for the Battery and Power section:

    For 15" MBP
    http://www.apple.com/macbookpro/specs.html

    For 13" MBP
    http://www.apple.com/macbookpro/specs-13inch.html

    Based on these URLs, the 15" MBP can use both the 85W and 60W bricks while the 13" MBP can only use the 60W one.
     
  9. rafaelc378

    rafaelc378 Active Member

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    I've been using an 85W charger for my 13" White MacBook for a year now and have not had any problems.
     
  10. alikishi

    alikishi Well-Known Member

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    what i know is that you can use the 85w adapter to charge laptops that use 60w magsafe adapter because the 85w can "switch" down
     
  11. extremeshot

    extremeshot PhilMUG Addict Member
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    Maybe Apple should update their MBP spec pages then? I'm sure there's a reason why they clearly stated that the 13" MBP uses the 60W brick and not 85W/60W like the 15" MBP.

    It's actually up to you if you want to go with it.
     
  12. elbert

    elbert Active Member

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    You can use the 85W charger even with a MacBook Air, which requires a only a 45W charger. It is the laptop regulates the charge that goes into the battery and not the charger itself, that's why it's safe to use a higher wattage MagSafe.

    Take into consideration that the LED Cinema Display has a MagSafe plug that's designed to work with ALL MacBooks with MagSafe connectors.

    MagSafe adapters (and any Apple Power adapter for that matter) are designed to do two tasks: charge the battery and provide power to the computer. If the battery is not fully charged, it'll do both at the same time. When topped up, it will simply provide power directly to the computer but cease charging the battery.

    What happens if you use a 60W MagSafe with an MBP? Well, depending on the computing load and the power requirement of the unit at the time it's plugged, the MagSafe may charge the battery and power the unit at the same time, or just do one of the two tasks. If the unit is idle, asleep or off, then it will surely charge the battery. If the power demand is high, it will cease charging the battery, but will provide power directly to the unit.

    To restate, all MagSafes are safe to use with all model MacBooks.
     

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