What level should I keep the battery at?.. And that 1GB image file..

[Jim Witte]

Hi,

   I mainly use my MacBook when I have power nearby, so can plug in  
if I need to.  Given this, is there a general level should I keep the  
battery at most of the time - ie, that I shouldn't charge it  
*above*?  I've read that LiIon batteries do best if you don't charge  
them beyond about 40% (or was it 60%?).  Is there a way  
(programmatically) to turn off the charging circuitry while the  
machine is still plugged in, so that if I say leave the thing plugged  
in overnight (I don't like leaving it overnight at about 9% or less -  
the battery is old enough that it has a way of going from about 4% to  
almost nothing rather quickly), it will stop charging when it gets to  
40-60%?  This of course would depend on the machine being awake (to  
run the program), unless this can be set in the charging firmware,  
which I doubt (unless the battery-computer connector itself could be  
hacked to "report" a full charge when the battery was only at x%)

   Another question regards the rather large-seeming ~1GB image file  
(compressed I think too!) that the kernal writes out whenever you put  
and Intel machine computer to sleep?  Is this just a failsafe in case  
the memory backup power fails, or is it needed for some reason by the  
EFI?  It would seem more feasible (maybe) just for Apple to design  
the memory system so that it could be kept re-freshed, while the rest  
of the computer was in sleep mode, or to just stick a 2GB flash card  
in the thing, and write the image to that (although that might  
actually be slower than the HDD - I'm not sure how fast the fastest  
flash drives are compared to laptop HDDs - and it could be cost- 
prohibitive)?  This makes me think twice before putting the computer  
to sleep if I'm going to be using it again in say, 20 minutes,  
because of the drive wear (I'm paranoid - I've never had a drive  
crash except for the *really* old 20 *MB* Jasmine drive, and I  
remember when *512 MB* was considred REALLY big!)  On the upside,  
perhaps the drive will fail before the computer is out of warranty  
(nah - probably not)..

Jim