10.2.1 Update: Released 9/18. One reader in the forums thought the 10.2.1 update seemed to help battery life. If anyone can confirm that let me know. I've posted a page of other 10.2.1 update reader reports.
(Frequently Updated with more reports)
Yesterday's news had a report on lower (appx 25%) battery run-time from a Pismo owner that just upgraded to 10.2. I've received nearly a dozen replies from PowerBook and iBook owners (mostly PB). The vast majority of early reports did note a reduction in run-time after the 10.2 upgrade. (But the later reports had more positive results noted.) And several people noted that the "estimated" time remaining was not accurate (two reports noting that the battery had more life left even after reaching the zero point).
Note: One reader thought that Quartz Extreme was responsible for the lower battery life reports in 10.2 - however remember the Pismo and iBooks before the latest models (w/Radeon Mobility) do not have a Quartz Extreme supported graphics chip, so that is not a factor for those systems. For Notebooks that have Quartz Extreme supported graphics chips (fall 2001 PowerBook G4s, 2002 DVI PowerBook G4s), it's possible using OpenGL for 2D graphics might increase power usage by the graphics chip (and if the added heat causes the fans to turn on more frequently that would draw more power). I noted in my PB G4/800 DVI review that 3D games like openGL Quake3 turn the fans on high quickly, but I have not run 10.2 on the PB G4 DVI to see if it affects fan activity or battery life.
Higher Battery Drain in 10.2 During Sleep? This was not related to the original Pismo owner's request that started this page (faster battery drain during normal use), but there was a problem with early/beta OS X versions regarding (much) higher than normal battery drain during sleep. One reader noted that some people are also reporting this with OS X 10.2.0 (Note - see the reader report below that tested battery drain during sleep with a PowerBook G4. He saw no difference in power draw in 10.1.5 vs 10.2 in that test, but did see higher wattage draw in 10.2 during use.)
Reader Reports on Jaguar/10.2 Battery Life: (most recent first - due to mail overload I cannot reply to these mails, but thanks to all that sent them.)
10.2.1 increased battery life on 14" iBook 700/640MB by 1 hour (from 4 hours
max life to 5 hours max life). Drainage seems more realistic now too (i.e.
not draining at 2x speed as in 10.2).
Just thought I'd throw my comments and observations in to the Jaguar battery
life discussion. From what I can tell (at least, from my own experience),
the reason for the reduced battery life is probably that Jaguar is not
spinning down the hard drive after it has been idle, even when running on
battery power. Since upgrading to Jaguar, my PowerBook G3/400 (FireWire/Pismo)
hard drive _never_ spins down. Well, not until the whole system goes to
I've tried all sorts of Energy Saver & Power Manager "tricks", but the hard
drive flatly refuses to spin down before entire system sleep, whether on
Power Adapter or Battery. This is especially alarming on battery power,
since HD spin down is one important contributor to that ~5 hour battery life
that most recent Apple laptops are known for. When reading a web page, for
example, my system used to spin down the drive, since nothing was really
occurring except for IE reading some more data from its RAM cache as I
scrolled the page. Now, with Jaguar, despite the fact that the HD is not
needed, it remains on.
While I still maintain that my hard drive is very stubborn WRT spinning
down, it actually did spin down just a few minutes ago. Suffice it to say
that this is a very rare occurrence these days under Jaguar... :)
I want to comment on battery life with my iBook in OS X Jaguar.
I have a pretty new 12" 700 mhz iBook which has great battery life in
OS 9 (with the brightness set to about 3/4 I get well over 4 hours with
light use like internet browsing and office tasks and even watching a
full-lenght DVD doesn't drain the battery below 40%).
In OS X 10.1.4-5 the battery life was a lot less than under OS 9. This
didn't change much with Jaguar.
Yesterday I installed the 10.2.1 update and was pleasantly surprised to
see my iBook running for about 4 hours off the fully charged battery.
During those 4 hours I mainly read articles on the Internet (using
Airport) and watched Quicktime streams at the same time. I had Marine
Aquarium running as a screen saver at times when I didnt use the iBook
(MA makes heavy use of the cpu and graphics chip).
I'm really pleased with 4 hours of operating time on my iBook
especially compared to the results in 10.1.x and 10.2.0.
There is one bug I noticed that's not been fixed with 10.2.1.
When I move the mouse toward the dock when the computer is busy and the
dock doesn't come out right away (i use the options of having the dock
pop out when you move the mouse toward the edge of the screen and dock
magnification) and I withdraw the mouse before the dock came out it
gets stuck. That means that the dock is half way out and stays there
until I move the mouse back to the edge. Then the the dock first
disappears and then comes out all the way.
However, I'm not sure if this is a bug in Jaguar since I use ClearDock
to make the background of the dock transparent and this might be
causing this (installed ClearDock right after Jag so I can't say if
this happens without ClearDock).
Another thing I noticed is that the Jaguar version of Quicktime
Streaming Server (installed on the client version of Jaguar which is
officially unsupported even though Apple stated that QTSS will work on
non-server OS X) seems to have a minimum buffer delay of about 8
seconds. On OS X Server 10.1.5 (Xserve version) it is only about 3
seconds. This is quite annoying if you want to use QTSS to deliver
somewhat realtime media (like you need for video chats etc).
Other than that I only noticed improvements with the update on my iBook
I also use a Sawtooth 350 without QE support and feel that the machine
now seems a bit more sluggish compared to 10.1.5
The main machine I use with 10.2.1 is a PowerBook G4/800, which to me feels faster in 10.2.1 than any previous OS X version. I honestly am starting to use OS X on that machine 100% of the time, whereas in the past I primarily used OS 9.2.2. (Used on AC power most all the time - not checked battery life in 10.2.1 yet, but battery runtime took a nosedive in OS 9 it seems shortly after it was new, even with the most conservative settings.)
Based on a 40 minute run on the battery surfing the web with normal brightness setting I would say that battery life or drain (usage) is improved. This Pismo 400/320 started with a full 3 hours (previous reading with 10.2 was only slightly less), after 40 minutes the battery showed about 2:20 remaining. Under 10.2 I seam to recall a much faster drain time however, I did not record the previous times.
Both my 600 and 700 iBooks sleep for days. Last night, under 10.2.1, the 700
ran for a loooong time, well over 3 1/2 hours, which is longer than I
remember it ran under anything before 10.2.1, and on automatic.
Two tricks I haven't seen posted is o extend your battery life on you
PowerBook is to do the following.
1 Select the lowest brightness of the screen. This may seem a simple
thing but I have managed to squeeze even more time out of my PowerBook G4
500. Just turn the brightness all the way down until its off (via the
keyboard controls) and then press the brightness up just once so its at one
2 Turn off your network if you are not using it. Make a new Location
under network called 'Network Off' or something that you like. Under the
Network Port Configurations turn off Ethernet, Internal Modem and PPTP and
then click 'Apply Now'. this will save a lot of battery power as well as
the network interface is now not polling every second to see if the network
After doing this I can easily get a 1.5 DVD's playing back and about 5-6
hours if taking notes.
The LCD/backlight is one of the highest power drains in a notebook,
but the comments here relate to the fact 10.2 (with the same settings)
seemed to draw more power. (I disable the internal modem and ethernet
port even during normal use as I use Airport for the PowerBook. Turning
that off too would save some battery life of course when not in use.)
My machine specs are currently an iBook 500 MHz (first model), CD-RW,
256 MB RAM, always have brightness set at half way. Also installed is
an Airport card, but no external devices. I must note, I got a brand
new battery under warranty about 3 months ago, because the old battery
was not holding a very good charge.
Over the past couple of days, I have tested battery run time while
doing my favorite activity, watching TV, talking on iChat, and surfing
the web over Airport. The first time I tried this, I lasted for about
two hours. At that time, the battery indicator said just under 50%
Before writing this email, I have been doing these same activities for
the past 3.5 hours, and the battery indicator still says a solid 19%
left (42 minutes estimated). These numbers show approximately the same
as, or better battery times in 10.2 than I got in 10.1.5.
However, battery drain while asleep is a different issue. In 10.1.5,
the battery would eat up about 5% every 24 hours. With Jaguar, it eats
up 10% every 24 hours.
Overall, I am very satisfied with Jaguar, and happy my battery time is
still so good.
I installed Jaguar on iBook 500mhz/192meg/10gig over 10.1.5. Not a
clean install. Get
15 to 20% less time on computer.
However, Jaguar is so much better than 10.1.5 that I can live with the
shorter time. Almost never get the spinning wheel any more and when I
do it's for only a second. The less battery time is worth it for me.
OS seems to work fine with any programs and printer. Much faster and
responsive than 10.1.5.
So far I am very happy with this OS.
I have an iBook 500 Dual USB. Did a Wipe and Install of 10.2. Used to get
about 2.5 hours under 10.1.5 (Kids go to bed at 8:30 and I could work
through the Tonight Show Monologue). Now I'm Lucky to get 45 minutes.
Sometimes it shuts down with 30% left. Sometimes it's still running with 0%
left. Tried Resetting Power Monitor but no effect.
Some had thought a clean install might help on this issue (and a reason
why some noted shorter battery life and others not).
My battery life is much worse after upgrading to Jaguar.
ibook 700, 20gig, 640meg, airport on, lowest backlight level, low
performance setting, doing programing and surfing
10.1 indicated 5+ hours and seemed to last that amount. Never saw the
low power warning since I charge every night.
10.2 haven't seen >4 hours indicated, usually 3:55 but quickly drops to
~3. I keep forgetting to time it but I don't think it lasts as long as
it says, especially when it indicates less than 1.5 hours. The middle
left side of the bottom gets very hot during use which it did not do
Also running on AC the fan comes on during long compiles when the
screen is on which it never did with 10.1. Sleeping the screen during
long compiles must also sleep the graphics acceleration because the fan
soon shuts off and the unit cools down even though it running full bore.
I think the reason is that the PPC processor is much more energy
efficient at doing the screen compositing than the ATI chips.
I would sure wish the energy saver had an option to turn off quartz
acceleration when I'm on batteries. Looks like an opportunity for a
Several readers said the estimated time left in Jag. was not accurate
(i.e. they had more battery life left than indicated).
I just noticed that the runtime of my PowerBook G4 went down as
well (though I'm using Linux). This made me curious and thus I
tried how long it would run with the remaining 15% power, so I
shut everything unimportant down and killed the powermanagement
daemon, mounted the partitions readonly and waited; to my surprise it
reached 0% after 27 minutes but the machine didn't shut down.
So I decided to put some load on it. I ran
dd if=/dev/zero of=/dev/null
which uses the cpu to 100%. This ran *25* minutes before the machine
went down. After recharging it, OSX 10.1 and Linux showed a whopping
4.30h time at normal use (LCD full brightness, harddrive on) which
it really reached.
The culprit really is that the battery is telling wrong information to
the OS which makes it believe that there's far less power left than
really is. What one needs to recalibrate the battery is the ability
to turn *off* powermanagement which is AFAIR not possible with MacOS.
So my suggestion to all people experiencing weak batteries or increased
power consumption of the OS (why would it? This doesn't make much sense
except the OS is stressing the CPU drastically more which I can hardly
- Pick up some Linux CD
- Boot it
- Make sure "pmud" is *NOT* running
- Remove the powercord
- run "dd if=/dev/zero of=/dev/null" to speed up the process
- (check /proc/apm if you'd like to check the battery stats which are
- wait until the power drops out
- mail new info to email@example.com :)
Yeah, it's down. Tonight I got only one hour--one hour!--on my PB 550. I
used to easily get 2.5-3 hours without dimming the screen too much. This is
Otherwise, Jaguar's terrific.
I don't know how the other guy with a 700mhz ibook
gets 4 hours. In my state, I find that pretty amazing.
I can only get about an hour and a half with the 12.1
256mb 20gb 700mhz ibook I have. When I take it off the
AC it says 3:00, which quickly drops to 2:15, which is
a lie. When I run a game like 4x4 evo 2 the battery
only lasts about 45 min, on ruduced processor and all
the others (sleep,ect.) on the lowest. I don't know
whats up with that and I hate it. My old 5300 did 2:30
One thing, of great interest to people with more than one battery, is that
you can finally swap out your nearly dead battery for a fresh one, without
the system shutting off (when you're not on AC, of course). I don't know
how long it keeps a charge for the switch, but I'm now able to put the
system to sleep, pull the old battery out, put the fresh one in, and wake
the system back up without skipping a beat (or having to bootup again).
It usually takes me about 5 seconds to do this.
This is a very very nice addition to OS X.
I just installed Jaguar on my Ti400 and I enjoy the new "mature" Aqua.
But the reason I wrote was to say that in spite of what I have read, I
saw my battery life go up. For the first time since I've had this
machine, I've seen battery life hit 4 hours on the indicator. I know I
wont see that in real life, but it's different from what a lot of
people are reporting. Maybe it's that stuck red pixel. lol
I'm surprised at these reports. I've almost doubled the battery life on my
PowerBook G4/500. I used it to take notes at a conference for a solid 6
hours! I didn't get that kind of performance until I set the Energy Saver
preferences appropriately, though. They were defaulted to maximize
performance. I set the display sleep to 1 minute but since I was using it
frequently, the display was active most of the time. By the way, when the
low battery warning appeared, I swapped batteries immediately.
Thanks again for the advice on PowerBook hard drives. The 40GNX I put in my
new 667 Rev. C is just great. Actions like unstuffing files go buy in the
tick of a clock.
Anyway, about battery issues. I don't know if I would say I'm getting less
time, but I'm definitely encountering an error message regularly.
With a fully charged battery I unplug and go use it for 30 or 40 minutes,
then I put it to sleep. When I wake it up, I get the "Your Computer is
running on reserve power..." message. My battery indicator always reads high
enough for it not to be an issue, and the force sleep never comes about.
This has happened consistently since my 10.2 update. Take care and don't
work too hard.
(Reader FYI - the Systems page, PowerBook section has my illustrated HD upgrade guide for the PB G4 and PB G3s.)
My indigo iBook used to get 5:30 or more in OS 9, but the battery was newer then and I would spin down the HD from the Control Strip.
Under 10.0, the iBook usually indicated ~3 hours with a full charge.
10.1 upped the time to 3:45, but HD activity and noise seem to increase.
Under 10.2, my iBook indicated 5:05 and was quite accurate for 1:30 while surfing the Internet via AirPort. The HD never spun down, but was much quieter.
I have read that you need to periodically let your battery fully discharge in order to get accurate readings from the OS battery monitor.
Using my trusty Brand Electronics Model 4-1850 integrating power meter
on my Ti PowerBook 667 rev B I have measured sleep at about 2 watts and
average use (over weeks of actual use) at about 17.5 watts. These
measurements are made with the Ti's battery out so as not to measure
charging and also represent a wide range of activities (the Ti, just
sitting there running a screen saver, is about 14.5 watts with my
After 10.2 I performed a shorter test of about 8 hours of use. I get
the same for sleep -- 2 watts, but normal use has gone up to about 21
watts (probably +/- a watt).
So I'm seeing 20% greater energy consumption when the Ti is awake, no
change during sleep. I can't make any comment on Apple's measuring
software. It would be very interesting to try this on something like a
WallStreet, which doesn't make use of QE.
I have also experienced reduced battery life (and performance slowdown)
on my early iBook (dual USB 500MHz, slow system bus). Battery level
drops rapidly when the power cord is disconnected after an all night
charge. Before OS 10.2 I would routinely get about 4.5 hours before I
needed to recharge. Now I am lucky to get 3 hours. Disappointing. Also
disappointing is the slowdown in system performance. The only upside is
that Classic now boots and runs much faster than under 10.1.5. I hope
things are improved in subsequent updates.
I've had the incorrect battery warning as well on my old first revision PBG4
500. It typically happens after my laptop has been put to sleep for more
than a few hours (nearly every morning.) If I immediately close my laptop
putting it to sleep and reopen it after I receive the message, the menu bar
flips back to reporting seemingly accurate information.
I have a 667 PB. While it runs faster under 10.2, I've seen most if not all
of the complaints listed. I have 1 gig of memory on the machine. What I
really hate is the fast drain under sleep. I normally plug in my laptop for
charges at needed. Well at the rate of the sleep drain I've got to keep my
laptop plugged in over night.
All of this is the same behavior I've seen with other updates in OS X.
Hopefully Apple will get the battery management sorted out. I did find the
option for more battery life under Power Saver. That is on, but doesnŐt seem
to help much.
One of the bi8ggest problems I had under 10.1 was battery life. The lack of Energy Saver settings really affected my Powerbook G4 and if I was lucky I would get a maximum of 45 minutes to 1 hour of battery life!!!
Under 10.2 (we're not supposed to call it Jaguar here in the UK) my the time remaining indicator showed the same sort of figures as above but after an hour of so no sleep occurred. I continued to use the machine for another hour after the final shutdown warning. In the end I got around 2 hours which for me was a vast improvement.
After a full recharge I tried again. This time the time remaining indicated the correct time and I again got just over 2 hours of battery.
All in all a welcome improvement.
Battery time seems about the same in my Pismo (1GB RAM, 40GB Travelstar) with
10.2. One thing that I _have_ noticed is that I get the low battery dialog
after waking the machine from sleep, even though the battery shows four
LED's. When I plug the machine in and disconnect, things seems to clear
1:50 was the calculated time on a full battery, but another check showed
2:45 with a quick drop (within a minute) back to 1:53.
Another thing is that the battery and power adapter setups in Energy Saver
don't seem to be independent of each other.
And inaccurate time remaining calculations as well. Over the last half
hour or so the estimated remaining time on my battery has gone from 59%
to 56% but the charge percentage has gone from 48% to 29%. Something
doesn't jibe here. I'm using a dual USB 600 mhz iBook, the last one
before the bump to the video card that enables Quartz Extreme (doh!) on
Jaguar is great so far but I really hope Apple does something about
battery life soon. This sucks.
The "interesting" things I've seen on my Ti800 include warnings of
running on reserve power upon waking from sleep withe 80%+ power
remaining, new since Jag update. And I do not think the actual usage of
power has changed, but the menu bar indicator is pessimistic in Jag and
was optimistic on pre-Jag.
I too have seen the battery life indicator showing about an hour
less. Of course, I haven't "calibrated my battery" under 10.2. More
ominously, I just powered my Mac on after a night's sleep and it was
allegedly 20% down instead of the usual <10%.
(he later wrote)
Well, I ran the battery down and it still claims times of less than
(Reports added 8/30 and before follow)
Hi Mike,...like others, I have noticed a drop in battery life on my TiBook
G4 400 after the jaguar update. Even after being fully charged, as soon
as I disconnect the power adapter, the calculated battery time of 1:47
seems to be close (I get a little over 2 hours). This happens even with
the energy saver settings to longest battery life and the screen
brightness at 1 bar. Before the update, the battery lasted more than 3
I also noticed that even if the percent remaining is at 0%, the laptop
can still run for a good 30 minutes or so before it shuts down.
I cannot be sure, but I seem to be getting better battery life with
Jaguar on my Pismo 400. I have not let it run down all the way yet, but
the little estimator shows 3:51 remaining at 97%. Under 10.1.5, 100% =
I have slightly differing experience with my Pismo. It is a G3 400MHz
w/ 768 MB RAM and a Fujitsu 30 GB hard disk. I upgraded from MacOS
10.1.5 to 10.2.
First, when my Pismo is plugged in the battery monitor either states
"Calculating Time..." or some bogus time to being recharged.
When unplugged, I notice that initially it shows the same battery life
as being about the same as with 10.1.5...but that time seems to run
down more quickly. For example, I ride with the family down from our
home to town my wife's parents are from...which is about 2:15. My
Pismo under 10.1.5 would make that trip and just then be needing to be
shut down. Under 10.2 I'm still about 30 minutes before reaching our
destination when the battery monitor shows just a couple minutes left.
Well, once I got to talking and didn't shut it down, and it was still
running....suggesting that the time left on the battery monitor is
wrong. Today I tested that theory.
I let the battery run down to where the it said 0:02 time
remaining...then 0:01...then it said "Calculating time..." again. And
it stayed that way for about 15 more minutes before the system went
into sleep mode automatically.
So, perhaps 10.2 just cannot calculate the battery life on the Pismo
I am getting better battery life in OS 10.2 than I have in any other
Mac OS. On a PowerBook Wallstreet Rev 2
Browsing the Internet while listening to music, all power-saving
options off, battery charged (Doh!):
OS 8.6: 2 Hours 12 Minutes
OS 9.2: 2 Hours 28 Minutes
OS 10.2: 2 Hours 57 Minutes
Just unplugged the power on my 500Mhz G4 Powerbook : 2hours and 54 mn
left, decreasing very fast..
On my Energy saver preference panel, battery charge indicates
1079566716 percent !!!!
(cropped area from attached screenshot)
I have a 466MHz iBook SE and do not notice any perceptible change in
discharge time of the battery. However I am very envious of the folks
with PowerBooks and the newer iBooks as quite honestly if I am just
surfing and checking e-mail with this thing unplugged I am lucky to get
over an hour of battery time in OS X. In OS 9 it'll last a few hours.
I have an ibook dual usb (500). I to have notice less battery time.
Yesterday a strange thing happen. My battery was fully load (showing
100%) I unplug it And I had less then 2 hours available...
When it went to 0% i let it run. Ibook didn't go to sleep but the
battery indicator was showing calculating... It went like that for
about 55 minutes. My setting are 3 minutes for computer and 1 minutes
(Early reports from the initial posting today follow)
Yep, there is a big difference in your battery charge. I could run my
ibook w/normal setting for about 4-5 hrs before, now w/Jaguar unless i
have it on longest battery life, i only get about 3.5-4.5
yep: MUCH shorter than in 10.1.5.
Powerbook 667 (2002) 1gb RAM.
On battery, it used to hover around 4 hours when fully charged, screen dimmed and I was reading email on the train. Now it NEVER gets above 2h45m.
Digital Media Consultant
I own a Pismo. Had it since mar of 2000. I am also an experienced mac guy,
so my energy settings are consistent. Battery life is 20 to 25% less then
before. Also, everything runs sluggish (excel, word, in-design... Etc.) I
have a new travelstar 5400rpm drive with plenty of ram. When I get a
chance, I'm gonna reinstall (clean instead of update) the OS to see if I can
get the speed improvement everyone else is talking about. All in All 9.2.2
was faster, 10.1.5 was fast, OSX.2 is slow comparitively speeking.
Put me on the list of reduced battery time PowerBooks.
I installed Jaguar last night and my TiBook 400 shutdown around 3:30 am .
It typically last all day under my normal use.
I have a PISMO g3 400 powerbook, In OS 9 I was able to get a good 3
hours of battery life yet ever since the upgrade to Jaguar the battery
now only lasts a mere 1hour and 15 minutes. I set the energy saver
setting to longest battery life as well as turning off Airport
(powerbook connects to the web via Internet sharing on my G4 450
Sawtooth) and dimming the screen to half of the brightness level.
Pismo carries a 10gb HD, 512MB RAM, Airport Card, One battery and one
dvd/cd drive. I've tried several configurations but all end up lasting
an hour and 10 odd minutes. Would be nice to get back the battery life
that OS 9 provided. However I'm open to any/all options and suggestions
that are out there on expanding the battery life on Pismo Powerbooks.
I concur with this. I have a Pismo that I am setting up as a music
server and running on battery power, I too see about 25% less battery
life running 10.2
(name withheld by request)
I have also experienced a significant battery life drop after installing Jaguar on my Pismo. My Pismo has the PowerLogix G4/500 upgrade, but the battery life was fine in 10.1.5. I also installed an IBM 40GNX 5400 rpm hard drive when I first installed Jaguar, so I wasn*t sure if drop in battery life was due to the hard drive or 10.2. However, I seem to also have less battery life in OS 9.2 as well, so I*m assuming it*s due to the faster spinning hard drive. My stock IBM drive was rated at 0.5A power consumption, while the new one is rated at 1.0A.
No official benchmarks for you yet, by my perception on Pismo battery life
is the same as your other reports: battery life is shorter on my Pismo
under 10.2. One interesting note: the revised Energy Saver preference panel
in 10.2 estimates remaining battery life based upon the adjustments you make
to that panel.
Even on the "longest battery life" setting, it estimates
battery life to be far shorter than I used to get under OS 9 or earlier
versions of OS X. That's a bummer. Thank goodness I bought that extra
Just thought I would drop you a note to let you know that I too had my
battery life drop when upgrading to Jaguar. I have an iBook
700/14"/512MB. Under 10.1.4 I would get a little over 5 hours on a
full charge. Under 10.2 that time has shrunk to just under 4 hours.
Hope the next update fixes it. Thanks.
This reader noted better battery life:
I own a 400Mhz G4 Powerbook and have upgraded to Jaguar. When I unplug
my laptop I set the energy saver setting to the default longest battery
life setting. With this set I have noticed an additional 30 minutes in
battery life over the previous 10.1.5.
Before you evaluate the responses to your Pismo battery life survey, ask your respondents what their Energy Saver settings are.
Jaguar now has many of the PowerBook-specific Energy Saver settings from OS 9 and missing from X 10.1, such as hard disk spindown and separate Energy Saver sets for battery and power adapter. If users haven't discovered these (you have to click Details), they may not be getting optimal battery life, and you may not be getting good survey data.
Some noted lower life seen even with max conservation settings - and the initial complaint about 25% or so battery run-time reduction was from a reader that used the powerbook constantlly - where energy saver settings would have far less effect. (he was comparing run time from extended work periods where the PB was not left idle for any period of time).
There have been some problems noted in waking from sleep (from desktop and notebook users) in 10.2 also. Some say that when odd things happen after an Upgrade install, that performing a clean 10.2 install may help. (The old zapping the pram, resetting the power manager is also a common tip - although it may not help.)
If any other Powerbook/iBook owners have noticed reduced battery time in Jaguar, let me know.
(Note - I'm overloaded in emails and work currently, so I will not be able to reply to these mails.)