CPU Throttling with Battery removed

Discussion in 'MacBook Pro' started by dmo580, Jun 23, 2008.

  1. dmo580 macrumors member

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    Jun 23, 2008
    #1
    Hey guys, so my Macbook Pro is my new baby and instead of having 30 minutes of battery life like my old Dell 600m even though I used tons of AC power, I'd like to remove my battery when using AC power now. Before you all jump in to say that improved circuitry and Li-Ion batteries don't suffer from as many problems nowadays, and how the battery won't charge until it drops till 95%, if anyone really studied batteries, everyone knows that batteries drain over time, and that recharging of the battery will be inevitable when you areplugged in on AC power for prolonged periods of time.

    The problem is that Apple forces the CPU down to only 50% speed max (1.2ghz) when you remove the battery (WTF). This doesn't make sense because without a battery you're obviously on AC power, and why would they limit you to only 1.2ghz? Doesn't make sense to me.

    Is there any way to counter this or is the only way to have to stick in the battery.

    Also, if you're telling me to crank the power settings to better performance, that's not going to solve it. Pulling out the battery just slashes my CPU in half, and it's retarded that I can't watch a ****ing 1080p movie without having to stick my battery back in.
     
  2. eXan macrumors 601

    eXan

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    #2
    Sometimes the laptop uses more power than MagSafe can provide. Thats why they limit the CPU speed in order to prevent that without battery because otherwise your Mac will shut down.
     
  3. alphaod macrumors Core

    alphaod

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  4. e12a macrumors 68000

    e12a

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    #4
    agreed. Removing your battery does not prolong its life. They have a fixed decay rate, whether you're using it in your computer or not.

    Correct.

    a battery that's brand new but a few years old will not have 100% health like a battery fresh out of the factory.
     
  5. kgeier82 macrumors 65816

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    Feb 18, 2008
    #5
    your kidding right?

    a laptop NEVER uses more power than the AC can provide, period.

    if you believe this, explain to me after 6hrs of max load on both the video card, and CPU, that my battery hasnt depleted.


    I posted that the macs throttle the CPU with the battery removed in the CoreDuo days, no one looked twice at it. There is something to do with the circuitry of the laptops that requires the battery be in to run full power through the laptop. BUT IT NEVER USES THE BATTERY WHEN PLUGGED IN AC.

    the MBP adapters are rated at 85watts of power. That adapter HANDLES both full load on the machine, and charging at the same time. Running the MBP at full load should never use more than 50-60 watts or so of that 85, ever.

    this is 110% correct. Use the battery, leave it in. There isnt ***** you can do to prolong the batteries lifetime. It will die when it dies. Leave it in the machine.
     
  6. aquajet macrumors 68020

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    #6
    No. No kidding going on here.

    Read this.

    Not quite. Higher temperatures can accelerate the aging process, which is something that can occur in laptops.

    Read this too.
     
  7. kgeier82 macrumors 65816

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    Feb 18, 2008
    #7
    key word "can". Sure having it in could heat it up slightly more. That battery is still gonna live about the same time, little heat or not. The pro never heats the batttery up that much, nothing like the cpu temps.

    I love to see people that baby the battery. Its gonna be dead in 2yrs time anyways, just use it. Who in their right mind would leave their laptop in a car, IN THE HOT SUN. the battery is the least of this persons worries :)
     
  8. dmo580 thread starter macrumors member

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    Jun 23, 2008
    #8
    Ok, here's the thing, your battery is gonna lose charge everyday, just a bit. I leave it in AC for like 5 day straight currently. Can you tell me how many times it's going to charge the battery during that time? Maybe a few times, but if I can reduce that to 0 doesn't it help?

    Like someone else said, the MPB should not be using more than 85W of power. That's like saying if you're gaming 6 hrs straight with AC power and battery, that the AC cannot provide enough and that you drain battery, so after a while, you're guaranteed to run out of power. How absurd is that?

    I know a lot of users and I guess not mac users who take out their battery, but I guess PC Users. Does it prolong the battery? Yeah, it sure does, but a lot of you are arguing that it doesn't help that much. You're probably right. I'm not here to argue what's more worthwhile or whatever, but I'm just wondering if there's ANY WAY to get around this. Macs are programmed so they require a damn battery in to run full power. Does this make sense? I can't understand WHY Apple has this except for the fact that you could possibly draw more than 85W of power. Maybe this is for the idiots who plug in the 60W adapter into their MBP thinking it'll still survive.

    All I want to know if there's a workaround or not. Sure I'll be glad to plop in my battery I guess, but to know that I'll need to spend $100 in 2 years when I probably have only used say 100 full charge cycles but because of constant recharging from 95% => 100% that my battery is dead...
     
  9. lancestraz macrumors 6502a

    lancestraz

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    RI
    #9
    Look for a used battery on ebay and use that when you're running on A/C power.

    Even though you can't think of a reason why Apple would do something like this, I'm sure there is a reason. Apple isn't doing this for giggles.
     
  10. eXan macrumors 601

    eXan

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    #10
    You understand it wrong. It doesn't ALWAYS drain the battery when under heavy load, it does only very OCCASIONALLY and for a VERY short time. In all the years I've owned a Mac notebook I NEVER saw it drain more than 2%, and I'm pushing my computers to the limits more often than not.

    About your PC friends who take out their battery... Either they don't know ****, just like you, or they have some cheap laptops from 5 years ago with old battery technology.

    Seriously, you shouldn't worry about leaving the battery in. I have my MacBook for 1.5 years and its at 125 battery cycles currently. Over time it has lost only half an hour battery time so now I get about 3.5 hours instead of 4 under the same conditions. I never took out the battery.
     
  11. kgeier82 macrumors 65816

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    Feb 18, 2008
    #11
    this is just another one of those "how to care best" for my battery threads.

    Ill save you the trouble, and cut to the end of it.

    Use the battery, leave it in, enjoy its benefits, and worry about something that requires a little more out of life.

    You can baby it to death if you like, or trash it, it doesnt matter. Either way, itll die one day, and youll have NOTHING to reference your methods to if you go one way or the other (baby it vs abuse).

    It doesnt matter in the long run. Thats how all these threads end, and its true.

    So like I said. If you want to be one of those anal people that removes the battery all the time, be my guest. But while your doing that, and running at half speed (which macs do for some reason UNKNOWN), ill be enjoy my battery on AC @ fullspeed. Its not worth the 1% you may save out of the batteries life, is it? Surely not.

    You have a better chance of the battery randomly crapping out one day, than you do of changing its life in any MEASURABLE amount.
     
  12. e12a macrumors 68000

    e12a

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    #12


    read.
     
  13. dmo580 thread starter macrumors member

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    Jun 23, 2008
    #13
    I never said it would drain the battery. I was explaining the absurdity of the 85W not being sufficient for the MBP meaning the battery would be drained under heavy use.

    Do batteries drain on their own over time? Yes. You don't even need to be using it. I could throw my MBP battery out and let it sit and it'll drain. IDEALLY it drains at the same rate as the battery would if it's plugged in and using AC power because the battery shouldnt even be used.

    How much it drains depends on ambient conditions. It's summer now. Yeah it heats up in my house.

    Taking out the battery DOES in fact help improve battery life. Like I illustrated before. Over a week of use, the battery would be charged just a little if continuously under AC power, whereas if you take it out it wouldn't be affected. Additionally, I pointed out that the difference is small, hey I like to take care of my battery ok?

    I don't know **** just like my friends? And what qualification do you have? As a Materials Science Engineer I think I do know battery technology a little better than most people. I'm not even going to jump into a stupid debate about this.

    What I'm just wondering is if there's a workaround to get around the throttling. Additionally, I'm trying to discover WHY Apple even throttles the CPU because... well it doesn't make sense to. Honestly, you spend all your time criticizing me for taking out my battery when well... there's at least a legitimate reason, while Apple throttles the CPU when you take out the battery for.... well, I have yet to even find a logical explanation for that. Maybe you care to explain it since clearly Apple has better logic than I do right?
     
  14. lancestraz macrumors 6502a

    lancestraz

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    RI
    #14
    You have already tested and determined that removing the battery while using A/C power prolongs the life of the battery and you are right. What works for you might not work/noticed by others, however, so they might disagree.

    I've never heard of a workaround and a search on Google didn't turn up anything. :(


    Yes I saw that but as you can see above the OP thinks Apple is making that up.
    It may not be logical, or the truth, (PR BS, eh) but there is something --to boring or complicated to tell consumers-- that made Apple do this.
    Iit probable is what they say it is, though. However crazy it sounds. Why would they lie? :eek:
     
  15. eXan macrumors 601

    eXan

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    #15
    You say it's better for the battery if you don't keep it in your MacBook Pro, but where is the proof of that? I'd like to see some independent testing done with the same kind of battery. This should end our little debate and clear things up.

    You also say that you like to keep your battery in the best possible shape, but I'd rather have my CPU work twice as fast. Even for 10% longer battery life I'd still take CPU speed instead. Personal opinion I guess.

    The reason CPU is being throttled is given in post #12.
     
  16. elmateo487 macrumors 6502a

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    Jun 12, 2008
    #16
    wow. You people need to chill out. Give the facts, and lets not slap each others grandmas while doing it. Goodness.
     
  17. NODEraser macrumors newbie

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    Gladstone, Oregon
    #17
    Perhaps the underclocking was designed in case the computer gets plugged in to a 65W MacBook power supply?
     
  18. dmo580 thread starter macrumors member

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    Jun 23, 2008
    #18
    Why removing the battery is better? Well let's say you plug in for a week. Li-Ion batteries lose about 1% of charge each day on average. More if in heat, or depending on other ambient conditions. Whatever right? In some ways my MBP serves as a desktop upstairs. My real workstation is downstairs and I'm on that a good chunk of the time, but when I retire to my room upstairs or whatever I'm on my MBP. What I'm saying is to prevent the battery from being continuously charged, I remove the battery. Now I understand apple isn't stupid and probably programmed their batteries so its not continously charging, and so that it charges only when the charge drops to a certain %. Still, that means given a certain amount of battery drain, the battery will be recharged a few times over extended use when plugged in. That's a given unless you're telling me 100 days later the battery will still not need a recharge yet.

    The idea of removing your battery is so that it drains and doesnt get recharged by the AC adapter at all. So that wheny ou really do need to unplug and go on battery power, you slap in your battery that has been allowed to drain until... well when you need it. Thus you save a few recharges here and there. Now they aren't full recharge cycles anyways that you're saving, so I understand the difference is not night and day. However, we all know that there are limited charges on a battery before they start going to crap because well... it's a chemical reaction and no matter how you try to recharge, there's thermal losses and inefficiencies that prevent you from ever returning to 100% of the original charge. It's just that the decay becomes exponential after say 300 charges or so.

    To me it's no inconvenience to turn on my macbook and remove the battery. It's a 2 second thing, and so for me it's like why not remove it when I'm plugged in anyways? It's only a 2 second job. Of course I can leave it in and I'm totally fine with it. So that's all I'm wondering. Why can't Apple let me do it?

    Now people point out that 85W is not enough, but I somehow beg to differ. My friend runs a Dell Inspiron 1525 with a Merom 2.2 and an 8600GT. The same happens with another friend's Dell XPS1530. These are all 15" laptops equivalent to the MBP. Dell supplies 90W adapters and theres no throttling when the battery is removed. You're telling me 5W is that big of a difference? Or maybe Apple is being cautious? I can't see how my Penryn 2.4 with 8600 GT will be eating more power. Methinks Apple is just playing it safe. Because if 85W truly isnt enough, then I could run say 3D Mark (both CPU and GPU intensive) on loop while plugged in and theoretically at a certain point my laptop will just die because 85W is not enough and the battery will end up being drained?

    That's why I feel that this 85W being insufficient claim is absurd. I don't think Apple would've designed something that can't even power its laptop all the way, and rather it's a precaution Apple implemented with the MBP, especially if the less tech saavy crowd tries to apply the 60W connector of the macbook.

    Shrug. I just feel it's unfortunate that there's no workaround. Honestly, I love my MBP and as a PC user still, I have no complaints about my MBP except for this battery issue. Yeah I love OSX, and even though I dualbooted Vista, I'm on OSX about 99% of the time when I use my MBP (I still use XP on my workstation desktop)
     
  19. eXan macrumors 601

    eXan

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    #19
    MacBook/Pro/Air all use lithium-polymer batteries, so the technology is different.

    You still haven't provided any proof of your claim that taking out the battery gives you a meaningful improvement in battery life. What are you basing your words on?
     
  20. Tallest Skil macrumors P6

    Tallest Skil

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    #21
    So by that mindset, my G3 iBook battery should have died nearly five years ago; 100 days after it was bought.

    Well well well...

    Also, my iPhone, DS, crappy Verizon cell, and three iPods still work.
     
  21. Eric. macrumors regular

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    Mar 30, 2008
    #22
    He's referring to the charge. Not the battery health. Meaning that the battery would be dead after sitting for 100 days not installed.
     
  22. alphaod macrumors Core

    alphaod

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    #23
    The capacity loss is minimized when the charge is stored at 60%.
     
  23. dmo580 thread starter macrumors member

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    Jun 23, 2008
    #24
    Engineering rationale my friend. Real experimentation would take too long to demonstrate, but it's simple in theory. And please don't come telling me that there's no proof so my words are meaningless.

    The battery whether in or out will lose charge over time. Apple designs the batteries to recharge at what. 95%? If you have continuous recharge cycles of 95 => 100% you will naturally run the battery health down faster than if you took it out and let it drop to 0 and then did 1 full charge cycle. It's a given and that's why a lot of people take out their batteries in general. Honestly, this doesn't really require much proof.

    Now does it help that much? A little, but probably not. It would help more if you're literally 24/7 plugged into the wall.

    Apple honestly did put in thought into their batteries so they don't charge until they drop to like 95%. My Dell clearly ran out of batteries way too quickly, and I can assure you I did not go through 300 charge cycles that quickly considering I'm plugged in most of the time. So yes in Apple's case, their batteries might survive longer, but it doesn't HURT to find a way to maximize it right? However, for convenience's sake since there is throttling, I'll leave my battery in.
     
  24. gnasher729 macrumors P6

    gnasher729

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    Nov 25, 2005
    #25
    If you check how much you pay for 200 MHz more, and how much a new battery costs, I think the maths is pretty clear. Ten percent more battery life means maybe $10 per year. 200 MHz costs a few hundred, and here we are talking about running at half speed.

    And if the original poster ever knocks off his Magsafe adapter while running without battery he will kick himself.
     

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