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PowerBook 12" clock battery?

Message #1 - Posted 2008/12/21 - Steven Fisher

Does the 12" PowerBook G4 (1GHz, i.e. early DVI) have a clock battery? I know it doesn't have a full backup battery, but it seems to be losing the system clock a lot lately and I don't remember that happening before...

Message #2 - Posted 2008/12/21 - Steve Hix

Previously, Steven Fisher wrote:

Does the 12" PowerBook G4 (1GHz, i.e. early DVI) have a clock battery? I know it doesn't have a full backup battery, but it seems to be losing the system clock a lot lately and I don't remember that happening before...

This says it has no backup battery, just a capacitor to maintain PRAM setting long enough to swap batteries if not connected to AC:

http://support.apple.com/kb/TA25911?viewlocale=en_US

Message #3 - Posted 2008/12/21 - Steven Fisher

Previously, Steve Hix wrote:

Previously, Steven Fisher wrote:

Does the 12" PowerBook G4 (1GHz, i.e. early DVI) have a clock battery? I know it doesn't have a full backup battery, but it seems to be losing the system clock a lot lately and I don't remember that happening before...

This says it has no backup battery, just a capacitor to maintain PRAM setting long enough to swap batteries if not connected to AC:

http://support.apple.com/kb/TA25911?viewlocale=en_US

Okay, then. It's probably just a consequence of my wife using it differently than me -- she tends to use it until the battery is almost dead, then forget about it for three days. I always kept it fully recharged. Thanks for the link. :)

Message #4 - Posted 2008/12/21 - Tom Anderson

On Sun, 21 Dec 2008, Steve Hix wrote:

Previously, Steven Fisher wrote:

Does the 12" PowerBook G4 (1GHz, i.e. early DVI) have a clock battery? I know it doesn't have a full backup battery, but it seems to be losing the system clock a lot lately and I don't remember that happening before...

This says it has no backup battery, just a capacitor to maintain PRAM setting long enough to swap batteries if not connected to AC:

http://support.apple.com/kb/TA25911?viewlocale=en_US

It really doesn't have a PRAM battery? Wow. That's kind of insane.

tom

Change happens with ball-flattening speed. -- Thomas Edison

Message #5 - Posted 2008/12/21 - Steve Hix

Previously, Tom Anderson wrote:

On Sun, 21 Dec 2008, Steve Hix wrote:

Previously, Steven Fisher wrote:

Does the 12" PowerBook G4 (1GHz, i.e. early DVI) have a clock battery? I know it doesn't have a full backup battery, but it seems to be losing the system clock a lot lately and I don't remember that happening before...

This says it has no backup battery, just a capacitor to maintain PRAM setting long enough to swap batteries if not connected to AC:

http://support.apple.com/kb/TA25911?viewlocale=en_US

It really doesn't have a PRAM battery? Wow. That's kind of insane.

Tradeoffs: you get rid of battery failure/leakage problems, in exchange for losing PRAM settings if you let the main battery go completely dead while disconnected from mains. (Which most people seem to not do often, if at all.)

That problem might go away of the PRAM was static RAM of some sort, but that probably wasn't a cost-effective option at the time of design.

Message #6 - Posted 2008/12/22 - Tom Anderson

On Sun, 21 Dec 2008, Steve Hix wrote:

Previously, Tom Anderson wrote:

On Sun, 21 Dec 2008, Steve Hix wrote:

Previously, Steven Fisher wrote:

Does the 12" PowerBook G4 (1GHz, i.e. early DVI) have a clock battery? I know it doesn't have a full backup battery, but it seems to be losing the system clock a lot lately and I don't remember that happening before...

This says it has no backup battery, just a capacitor to maintain PRAM setting long enough to swap batteries if not connected to AC:

http://support.apple.com/kb/TA25911?viewlocale=en_US

It really doesn't have a PRAM battery? Wow. That's kind of insane.

Tradeoffs: you get rid of battery failure/leakage problems, in exchange for losing PRAM settings if you let the main battery go completely dead while disconnected from mains. (Which most people seem to not do often, if at all.)

The battery failure problem is a bit of a red herring: without a PRAM battery, you effectively have a battery failure every time the main battery runs out! As for leakage - how often is that a problem? I don't think i've ever heard of it happening to anyone i know.

I suspect the main reason was to drive down costs and save space inside the case, which in a 12" machine is at an absolute premium.

That problem might go away of the PRAM was static RAM of some sort, but that probably wasn't a cost-effective option at the time of design.

Very true. I wonder if we'll start to see machines shipping with a small chunk of flash memory soldered onto the motherboard instead of battery-backed RAM. Possibly not, because of the much more complicated circuitry needed to control it. Plus, you still need a battery to keep the clock running. Although if we also start to get ubiquitous GPS, then since GPS gives you a highly accurate time, we might not need independent clocks at all. Although you'd be a bit stuffed if you were somewhere out of GPS reception.

tom

London has a suburb for every emotion. -- Cliff Laine

Message #7 - Posted 2008/12/22 - Clark Martin

Previously, Steve Hix wrote:

Previously, Tom Anderson wrote:

On Sun, 21 Dec 2008, Steve Hix wrote:

It really doesn't have a PRAM battery? Wow. That's kind of insane.

Not really. One common problem with old laptops is the PRAM battery dying. Since they are expensive and hard to access not having one is a plus.

Tradeoffs: you get rid of battery failure/leakage problems, in exchange for losing PRAM settings if you let the main battery go completely dead while disconnected from mains. (Which most people seem to not do often, if at all.)

That problem might go away of the PRAM was static RAM of some sort, but that probably wasn't a cost-effective option at the time of design.

The PRAM memory IS Static. But static memory still needs power. You could use flash but you still need power for the clock. And a few Kb of static RAM takes very little power, far less than the clock.

If they used a super cap it could probably run the PRAM / clock for a few days without battery or mains power.

Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting

"I'm a designated driver on the Information Super Highway"

Message #8 - Posted 2008/12/27 - Tom Anderson

On Mon, 22 Dec 2008, Clark Martin wrote:

Previously, Steve Hix wrote:

Previously, Tom Anderson wrote:

On Sun, 21 Dec 2008, Steve Hix wrote:

It really doesn't have a PRAM battery? Wow. That's kind of insane.

Not really. One common problem with old laptops is the PRAM battery dying. Since they are expensive and hard to access not having one is a plus.

No! Because the result of not having one is that you suffer the symptoms of a dead battery (clock not surviving a flat battery, not being able to change battery while sleeping, etc) ALL THE TIME. What you're saying is analogous to saying that because a common problem with old people is arthritic knees, not having any legs is a plus.

tom

Would you like to remember more?

Message #9 - Posted 2008/12/28 - Clark Martin

Previously, Tom Anderson wrote:

On Mon, 22 Dec 2008, Clark Martin wrote:

Previously, Steve Hix wrote:

Previously, Tom Anderson wrote:

On Sun, 21 Dec 2008, Steve Hix wrote:

It really doesn't have a PRAM battery? Wow. That's kind of insane.

Not really. One common problem with old laptops is the PRAM battery dying. Since they are expensive and hard to access not having one is a plus.

No! Because the result of not having one is that you suffer the symptoms of a dead battery (clock not surviving a flat battery, not being able to change battery while sleeping, etc) ALL THE TIME. What you're saying is analogous to saying that because a common problem with old people is arthritic knees, not having any legs is a plus.

You CAN change the battery while sleeping without loosing PRAM settings and the clock without a PRAM battery, that was pointed out earlier.

You shouldn't let your main battery go flat, it's bad for the battery and if the computer is asleep, it's bad for the computer. That is more serious than your clock going bonkers.

Your analogy is bogus.

Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting

"I'm a designated driver on the Information Super Highway"

Message #10 - Posted 2008/12/28 - nospam

Previously, Clark Martin wrote:

You CAN change the battery while sleeping without loosing PRAM settings and the clock without a PRAM battery, that was pointed out earlier.

but you can't change the battery while it's sleeping. i used to have an ibook and that thoroughly annoyed me.

You shouldn't let your main battery go flat, it's bad for the battery

batterie packs are designed to shut off before damage can occur.

and if the computer is asleep, it's bad for the computer.

how so? if the battery is discharged beyond a certain point, the computer won't wake up until it's plugged in.

Message #11 - Posted 2008/12/28 - Steve Hix

Previously, nospam wrote:

Previously, Clark Martin wrote:

You CAN change the battery while sleeping without loosing PRAM settings and the clock without a PRAM battery, that was pointed out earlier.

but you can't change the battery while it's sleeping.

You can if it's a 12" POWERBook. Which is what the OP was talking about.

i used to have an ibook and that thoroughly annoyed me.

Reasonably so. But that was in iBook.

You shouldn't let your main battery go flat, it's bad for the battery

batterie packs are designed to shut off before damage can occur.

And the safeguards *always* work, don't they?

and if the computer is asleep, it's bad for the computer.

how so? if the battery is discharged beyond a certain point, the computer won't wake up until it's plugged in.

By then it's not waking up so much as being raised from the dead.

Message #12 - Posted 2008/12/29 - Tom Anderson

On Sun, 28 Dec 2008, Clark Martin wrote:

Previously, Tom Anderson wrote:

On Mon, 22 Dec 2008, Clark Martin wrote:

Previously, Steve Hix wrote:

Previously, Tom Anderson wrote:

On Sun, 21 Dec 2008, Steve Hix wrote:

It really doesn't have a PRAM battery? Wow. That's kind of insane.

Not really. One common problem with old laptops is the PRAM battery dying. Since they are expensive and hard to access not having one is a plus.

No! Because the result of not having one is that you suffer the symptoms of a dead battery (clock not surviving a flat battery, not being able to change battery while sleeping, etc) ALL THE TIME. What you're saying is analogous to saying that because a common problem with old people is arthritic knees, not having any legs is a plus.

You CAN change the battery while sleeping without loosing PRAM settings and the clock without a PRAM battery, that was pointed out earlier.

You shouldn't let your main battery go flat, it's bad for the battery and if the computer is asleep, it's bad for the computer.

I've never heard either of those assertions before; could you direct me to more information on them?

tom

The whole of science is nothing more than a refinement of everyday thinking. -- Albert Einstein

Message #13 - Posted 2008/12/29 - Gregory Weston

Previously, Tom Anderson wrote:

On Sun, 28 Dec 2008, Clark Martin wrote:

Previously, Tom Anderson wrote:

On Mon, 22 Dec 2008, Clark Martin wrote:

Previously, Steve Hix wrote:

Previously, Tom Anderson wrote:

On Sun, 21 Dec 2008, Steve Hix wrote:

It really doesn't have a PRAM battery? Wow. That's kind of insane.

Not really. One common problem with old laptops is the PRAM battery dying. Since they are expensive and hard to access not having one is a plus.

No! Because the result of not having one is that you suffer the symptoms of a dead battery (clock not surviving a flat battery, not being able to change battery while sleeping, etc) ALL THE TIME. What you're saying is analogous to saying that because a common problem with old people is arthritic knees, not having any legs is a plus.

You CAN change the battery while sleeping without loosing PRAM settings and the clock without a PRAM battery, that was pointed out earlier.

You shouldn't let your main battery go flat, it's bad for the battery and if the computer is asleep, it's bad for the computer.

I've never heard either of those assertions before; could you direct me to more information on them?

tom

Considering that Apple explicitly recommends that notebook batteries be drained a few times a year to recalibrate the user feedback system, I doubt he'll be able to provide an authoritative source.

<http://support.apple.com/kb/HT1490>

"Harry?" Ron's voice was a mere whisper. "Do you smell something ... burning?" - Harry Potter and the Odor of the Phoenix

Message #14 - Posted 2009/01/03 - Steven Fisher

Previously, Tom Anderson wrote:

No! Because the result of not having one is that you suffer the symptoms of a dead battery (clock not surviving a flat battery, not being able to change battery while sleeping, etc) ALL THE TIME.

That's only true if the PowerBook requires an internal battery to do those things. If you don't have one when you're designing the hardware and software, you make different choices and don't have these problems.

The clock doesn't survive, sure, but that's it.

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