In article ,
Andy Cuffe wrote:

On Wed, 26 Oct 2005 23:25:49 GMT, Don Bruder wrote:



Dunno if it's still true in PC-land - I've been living in a Mac world
for a LONG time now - but when I was playing with them years ago, the

I've always wondered why the batteries in macs run down so quickly. I
rarely see a PC newer than 10 years old with a bad battery, but I
consistently see 3-5 year old macs with totally dead clock batteries.

I'm not absolutely certain on that myself, though many explanations have
been put forth over the years, with the one I think is probably "the
real situation" being that Macs (A) Don't cut the battery out of the
circuit when powered up and (B) the battery isn't just keeping the RTC
running, but also keeping a chunk of memory (which we call "PRAM" here
in Mac-land - holds various fairly-to-really critical information) alive.

Macs even have a much larger (and more expensive) lithium cell than
most PCs. I've seen a few 15 year old 486's with the same type and
brand battery used by apple that still measures full voltage.

I don't know for certain about measured voltage, but I've only actually
*NEEDED* (as opposed to "shotgunning" a startup issue) to replace one
battery in my stops to count Hmmm... I guess that would be about 8
Macs over the last 15 years or so. That was in a Performa 637CD that I
picked up at a thrift store for ten bucks. The machine I'm typing on, a
PowerMac 7500, came to me secondhand also, and as far as I have any way
to know, it's still running on the factory-installed battery - 10+ years
since it came off the line.

--
Don Bruder - - If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without my
ever knowing it arrived. Sorry... http://www.sonic.net/~dakidd for more info

Don Bruder ) writes:

I'm not absolutely certain on that myself, though many explanations have
been put forth over the years, with the one I think is probably "the
real situation" being that Macs (A) Don't cut the battery out of the
circuit when powered up and (B) the battery isn't just keeping the RTC
running, but also keeping a chunk of memory (which we call "PRAM" here
in Mac-land - holds various fairly-to-really critical information) alive.


That second means nothing in itself. "IBM PC" type computers have a tiny
bit of static RAM to hold the bios settings. If it wasn't there, and kept
alive, you'd always have to set those things every time you turn the computer
on.

Now, it may be that one uses more current than the other, but I can't
really see that being a significant difference.

Michael