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NuPower battery, sudden shutdown

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

Posted on Nov 21, 2007 11:23 PM

Reply
8 replies

Nov 28, 2007 7:24 PM in response to John Huber1

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.

thanks

Message was edited by: Joseph Vander

Nov 29, 2007 8:28 AM in response to Joseph Vander

+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.

John

NuPower battery, sudden shutdown

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