PB G4 Battery Woes - Sudden Shutdown


macrumors member
Original poster
Jun 17, 2004
Hi Everyone - I'm looking for a little help with my current Mac:

I have a 3 year old 15 inch 1.33 GHz PB that has been a great computer. Recently (and rather rapidly) the battery has had progressively shorter life, and now, if it is unplugged, it runs for about 5 minutes on battery, then the computer shuts down with no warning. There are a few odd things about this:
1) The computer does not sleep, it just shuts down
2) The battery indicator will say there is still about 15 minutes of battery life left just before it shuts down
3) After the shutdown, if I press the indicator light on the battery itself, 4 of the 5 green LEDs still light up

I'm wondering if it is a dead battery, or something wrong with how much charge the computer THINKS is in the battery (ie. some sort of power management issue). #2 and #3 make me lean towards something other than a dead battery.

Things I have tried so far to solve the problem:
1) PRAM reset
2) PMU reset (CAVEAT: for the model I have, it is supposed to be ppower off, ctrl-option-shift-power, wait 5 seconds, power on - I have tried that several times, but get no indicator that anything has actually happened - it does not make any noise (not sure if it should) and when I re-boot, the date and time and everything else look the same (and from reading forums about batteries and PMU resets, most people report a clearing of the date and time).
3) taking out and re-seating the battery

So, I guess I have 3 questions:
1) dead battery or power management problem?(or some other problem)
2) should I expect the PMU reset to clear the date and time? Is there some way to check if the PMU has been reset?
3) Any other suggestions about how to work out the problem? I'm a bit loathe to go to the genius bar, since my applecare expired 2 weeks ago (but not before I had a new screen put in!)

Thanks in advance for any help!



macrumors 6502a
Aug 6, 2006
Is your battery three years old, too? If so, then it sounds like it's time for a new battery! I wouldn't expect the battery to last longer than 2 and a half years or so.

On a related note, however, I'm having a similar problem in which my Powerbook cuts off before going to sleep...however, I have a less-than one year old battery that is still going strong. The battery lasts for a long time...but it still cuts off without sleeping. I've also tried resetting the PRAM and the PMU to no avail..


macrumors member
Original poster
Jun 17, 2004
Yes, the battery is 3 years old. It was (sadly) not one of the ones affected by the recall...


macrumors member
Jun 10, 2007
Yes, the battery is 3 years old. It was (sadly) not one of the ones affected by the recall...
seems to be a common trend (as with myself.)

People having AL PB that have terrible battery problems and overheating issues, but were ironically not included in the recall for a less severe battery problem.

Oh well, I love my new MBP all the more


macrumors 68000
Mar 9, 2006
The PMU reset shouldn't reset the date/time. Even if it does get reset, the second you grab a net connection, it will automatically set itself.

I doubt this will fix your problem, but shut down. Then, hold down the power button until you see the lid button light flashing and her a BOOOOOOP noise. That will reset your PMU.

Like others said, it's likely the battery needs to be replaced. The price isn't bad though... I think it's $150 Canadian if I recall correctly.