4 Replies Latest reply: Jan 24, 2008 5:59 PM by Allan Jones
Photon2 Level 1 Level 1 (25 points)
My PowerMac G4 MDD is about 4 years old now. I noticed a 3.6v lithium battery on the motherboard and was wondering if I should replace it before it goes dead, like preventative maintenance, or just wait for it to fail, if it ever does? If it does fail, what would happen? Thanks for details on this.

12" PowerBook G4, PowerMac G4 Dual MDD, Mac OS X (10.4.11)
  • Thomas Bryant Level 6 Level 6 (13,865 points)
    Hi! It depends on whether you leave it plugged in all the time. If it's plugged in the battery can last for many years although 4-5 is a good time to replace it. If it goes dead or starts getting real weak the clock will lose time if it's unplugged. A dead battery can keep one from booting and a clock that's losing time can really mess OSX up. Tom
  • Photon2 Level 1 Level 1 (25 points)
    If I wait to replace the battery and then find the computer will not boot one day, will I just get a blank screen, or...? Then is it just a matter of replacing the battery, or do you have to do a Pram reset or something? Thanks.
  • Thomas Bryant Level 6 Level 6 (13,865 points)
    Hi! It's really hard to tell. Sometimes they act one way and sometimes another. personally I've never had battery problems and I can't remember if I've ever replaced this one. I run 24/7/365 so the battery is only an issue for me when the power goes off. Tom
  • Allan Jones Level 7 Level 7 (33,015 points)
    Like Thomas said, it depends on the machine. In some, should the dead battery cause a boot failure, a second start will give a normal start-up. You may have to zap the PRAM to get a start, or start from a system CD and then warm boot from the hard drive. Fortunately, the G4s don't show some of the ill-tempered dead battery problems of older Macs with "Old World ROM."

    Batteries are reatively cheap if you order on-line, so it's a good idea to keep one around. I have two in the veggie drawer of our frig, stored for future need. Radio Shack has the correct battery as part number 23-026 but you have to look for the number as most clerks don't realize that they carry a Mac PRAM battery, However, RS has grown expensive--about US$15--so I only use them in an emergency.

    I get batteries on-line from:
    Other World Computing
    Operation Headgap Systems

    The latter pays the shipping, even if you buy only one little battery,