Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Notebook battery

  1. Jul 20, 2004 #1


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Maybe a really silly question, but if you're solely using power from the network.. can you just take the battery out of a notebook for safekeeping?
  2. jcsd
  3. Jul 20, 2004 #2
    Are you afraid someone will steal your battery but not the entire notebook?
  4. Jul 20, 2004 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    lol, no :rolleyes: it happened to you? :uhh:

    Having the battery plugged in all the time must be a strain on it right? especially since the bottom platform of notebooks can get really hot. Isn't it a common practice to remove batteries from devices that you're not using?
  5. Jul 20, 2004 #4
    Nope, but it seemed kind of odd to take out the battery for "safekeeping" (keeping it safe from thieves, I assumed). I mean, if someone wanted your laptop battery, it's probably not beneath them to just steal the entire laptop. But apparently, I assumed wrong... ;)
  6. Jul 20, 2004 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    If you have a laptop made in the last decade or so, it has sophisticated power electronics built into it. Once the battery is fully charged, it is disconnected from the charging circuitry while your laptop is on AC power. You're not putting any strain on the battery at all. The laptop was designed for the battery to be left in continually.

    - Warren
  7. Jul 22, 2004 #6
    I have always had my battery constantly connected to the laptop and using AC power and have encountered no problems whatsoever. But I have been told that it is good practice to actually complete discharge the battery once in a while (like once every couple of weeks) to optimise the battery life.
  8. Jul 22, 2004 #7
    This is less critical with Lithium batteries, which have less "memory" than some other types, but still a good idea. Whenever I start using battery power instead of AC, I allow it to completely discharge before recharging it.

    A late model laptop can actually run faster when plugged in to it's AC adapter. The circuitry of a mobil CPU and the charging system recognize the power source is "unlimited" and allow full capacity operation. The same notebook running on battery may reduce it's CPU speed and other operations to conserve power. The effect of this will be barely noticed except in some operations.
  9. Jul 22, 2004 #8
    This is actually something I have noticed with my laptop and it really pisses me off when I run on batteries to discharge it (and still want to load things up quickly)! Do you happen to know if there is a setting somewhere that can bypass this. i.e. make ur laptop run on full CPU power even when on batteries? Or is there anyway of knowing what CPU frequency the laptop runs at when on batteries.
  10. Jul 22, 2004 #9


    User Avatar

    Staff: Mentor

    Depends on the laptop. If you're lucky, there is a speed-step applet in the system tray...
  11. Jul 22, 2004 #10


    User Avatar

    Staff: Mentor

    Russ is correct. If it is a regular laptop (not a MAC, I am not familiar with those). Go to your control panel, power options, Intel(R) SpeedStep(TM) technology tab, It will say "when computer is running on batteries" and have a drop down box. Select "Maximum Performance".
  12. Jul 23, 2004 #11


    User Avatar
    Homework Helper

    There are definitely laptops less than 10 years old that can damage a battery if it is left in while the adapter is also plugged in (after the battery is fully charged that is). However, it could certainly be true that none have been made in the past 3 or 4 years with this problem.

    I've always just pulled the battery out by a half inch or so, so that it's not against the contacts. (I don't have a recent laptop though.)
  13. Jul 23, 2004 #12
    Thanks for the tip but the only tabs in Power Options I have are: Power Schemes, Alarms, Power Meter, Advanced and Hibernate. And none of these tabs have anything about Max Perf when on Batteries. And yet it is a Windows laptop. :confused:
  14. Jul 23, 2004 #13


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Yeah, I was actually more worried it could start leaking or that the heat from the laptop would radiate into it, which can't be good.
  15. Jul 23, 2004 #14
    But is it an Intel laptop? I know the newer AMDs have speed controls to reduce heat and conserve battery, but I don't know if they are controlable by the user.
  16. Jul 23, 2004 #15
    Yes it is an Intel P4 (I wouldn't trust AMDs or even Celerons actually)
  17. Jul 23, 2004 #16
    Check your BIOS, you may be able to enable other features that will allow you to control the speed.
  18. Aug 2, 2004 #17
    Yes, the heat is bad for the battery. I'm not sure how much damage the heat can really do, though.

    This is actually bad for lithium-ion batteries. Completely discharging puts strain on the batteries. The only kind of battery that this is good for are the ones that have "memory."

    All information was take from this website: http://www.batteryuniversity.com/parttwo-34.htm

    Here's the important part:
  19. Aug 2, 2004 #18
    "Yes it is an Intel P4 (I wouldn't trust AMDs or even Celerons actually)"

    P4's give off to much heat for Laptops and use to much energy, you should go for a PM (Centrino) which are far better adapted for Laptops...

    AMD are good procs for desktops, i have had no problems with AMD so I do not understand why you would not trust them?

    Celerons are far slower due to there lack of cache, and I would aggree dont go for a celeron if you need to use some proc hogging apps
  20. Aug 3, 2004 #19
    Thanks for this! I didn't actually realise that Lithium-Ion batteries didn't suffer from the memory effect. And it's quite interesting that they are also affected by high temperatures, although I doubt that my laptop goes above 40 in the battery area.
  21. Aug 3, 2004 #20
    Centrinos definitely use much less power than P4s and don't give off as much heat!! But just try doing some processor intensive task like video editing or even picture editing on a centrino and you will find the equivalent P4 does it much faster. Centrinos are good for people who want a light laptop but are not that bothered about performance.

    As for AMDs, from my experience, they have the tendency to crash way more often than P4s and my friends have noticed the same thing. Also AMDs don't do well heatwise (Check out http://www6.tomshardware.com/cpu/20010917/index.html for a test of how the P4 survives and an AMD dies when ran without a heatsink!

    The other reason I don't trust AMDs is that I generally believe in "You pay for what you get". So, as long as the market of AMDs are lower than P4s I wouldn't go and buy one unless you actually proove me that AMDs are actually better in ALL aspects.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Notebook battery
  1. My Notebook (Replies: 4)

  2. Notebook Battery (Replies: 0)

  3. NoteBook gaming (Replies: 9)