8 Replies Latest reply: Dec 2, 2007 12:55 PM by John Huber1
Lowell Ray Anderson Level 1 Level 1 (25 points)
The origional battery, after many cycles, would last less than an hour on a full charge. I replaced it with a Newer Technology NuPower Battery 74 Watt-Hour High Capacity for all Apple iBook G3/G4 Models 14". Battery performance has been excellent. But:

About This Mac - More Info… - Power - Battery Information: - First low level warning: No
I have drawn the battery down several times. Why does it say No?

When the old battery got very low there was an on screen warning that the computer was about to shut down due to lack of power. There is no such warning with the NuPower battery, it just shuts down with no warning. Why don't I get an on screen warning?

PowerMac G4 dual processor, Mac OS X (10.4.11), NuPower Battery
  • John Huber1 Level 6 Level 6 (17,745 points)
    Hi Lowell,

    Welcome to the Discussions.

    Only Apple batteries have the circuit in then that gives the Low Power warning. If that's important to you you'll have to return the NewPower one and go with Apple.

  • Joseph Vander Level 2 Level 2 (340 points)
    I have 3rd party batteries on both my TiBook and my iBook G4. I am not sure of the brand but I know it is the same brand and I think it is Encore for both computers.

    The Tibook (running Tiger) does give me a low power warning before it shuts down and goes into a deep sleep.

    The iBook (running Panther) gives no warning and you lose documents.

    Since they both have the same brand battery, I am not so sure that the explanation in the previous post fits my case. I rather think my problem is a PMU issue. I have tried the instructions for resetting PMU according to Apple:

    1. If the computer is on, turn it off.
    2. Reset the power manager by simultaneously pressing and then releasing Shift-Control-Option-Power on the keyboard. Do not press the fn (Function) key while using this combination of keystrokes.
    3. Wait 5 seconds.
    4. Press the Power button to restart the computer.

    This does not seem to help my low battery warning.

    Also, I don't get any indication as to whether I really reset the PMU. Is there a way to tell? I thought I would lose time and date settings after resetting the PMU but I don't.


    Message was edited by: Joseph Vander
  • John Huber1 Level 6 Level 6 (17,745 points)
    I got my information directly from OWC (NewPower). The circuit that controls low power sleep is built into the battery on iBooks and is a proprietary design. Only Apple batteries have it. It may be part of the computer on PowerBooks.

  • Joseph Vander Level 2 Level 2 (340 points)

    Thanks for the update. Your theory about a hardware difference between ibook and tibook is a good one. Different Operating Systems might be a factor also.

    Any comment on verifying if I really reset the PMU?

  • Joseph Vander Level 2 Level 2 (340 points)
    Answering my own query -

    I notice that my energy savings go to default after I reset PMU - so I guess I did succeed in resetting. Problem remains. So I guess Joun H has the right idea.

    Oh well, I'll buy Apple battery next time.
  • John Huber1 Level 6 Level 6 (17,745 points)
    +Different Operating Systems might be a factor also.+

    The PMU is part of the logic board and isn't affected by whatever OS is installed.

    +Any comment on verifying if I really reset the PMU?+

    I'm sure it did reset but if you want to test it, shut down your internet connection prior to resetting it. You should get a date and time warning upon restart.

  • Joseph Vander Level 2 Level 2 (340 points)
    Good news. I now am getting the warning message that the iBook is about to shut down. So resetting the PMU did seem to help in my case.

    I do not have NuPower. I think I have an Oncore (not Encore) battery. So apparently they have incorporated the necessary hardware in their battery.
  • John Huber1 Level 6 Level 6 (17,745 points)
    Thanks for the update.