[npeterh]

I calibrated my battery on my new Macbook Pro 1,83 exactly according to instructions, even let it sit in sleep overnight after it ran out before recharging.

Before I got almost 4 hours and way over 3 with light use and display at 50%. Now I get way less than 3 with lower settings, even tried with just one core running.

Any idea what is going on? Anyone else had the same problem?
I will never calibrate a new battery again until I see an issue with it!

[Wiskedjak]

Calibration does not affect your battery. Calibration only teaches your computer how to estimate the life of your battery. If you calibrate with your display at full bright, hd and dvd running, your battery will drain faster and your computer will estimate your battery life low. If you calibrate with energy settings low, your computer will estimate your battery life high. The best way to calibrate would be under your average use conditions.

[JKT]

What Wiskedjak said... the only way to determine your actual battery life is by using a stopwatch.

[Barefoot Matt]

Also, previous posters have determined that turning off one of the cores actually decreases battery life by making the other work harder.

[onlykaria]

i would kill for 3 hours right now, (after calibrating) i am getting one. with airport on and bluetooth off.

[amazing]

X-Charge is a great battery life timer

http://www.versiontracker.com/dyn/moreinfo/macosx/15982

onlykaria: try resetting the pmu (see link below.) if that doesn't give you 3 hours battery life, you need to call applecare or go to the genius bar (be sure to use x-charge to document the poor battery life) to get a new battery

http://docs.info.apple.com/article.html?artnum=303319

[John123]

Originally Posted by Wiskedjak

Calibration does not affect your battery. Calibration only teaches your computer how to estimate the life of your battery. If you calibrate with your display at full bright, hd and dvd running, your battery will drain faster and your computer will estimate your battery life low. If you calibrate with energy settings low, your computer will estimate your battery life high. The best way to calibrate would be under your average use conditions.

This is what I have always said and understood as well...but you know, in the Apple manual, it definitely implies there is a relationship between calibration and the life of the battery. Any idea why?

[paploo]

Originally Posted by John123

This is what I have always said and understood as well...but you know, in the Apple manual, it definitely implies there is a relationship between calibration and the life of the battery. Any idea why?

Probably because if you don't do the calibration steps, the PMU might be way off in its estimates of when it should force the computer to go to sleep. This is, of course, speculation, but I wouldn't be surprised if this is why.

I should note that I have the opposite problem on my 12" PowerBook: it way overestimates the battery life and suddenly puts itself to sleep when it thinks there is 50% battery left. I reset the PMU but it didn't fix it. Then again, that battery is kind of toasted anyway... it got too cold--probably about 10 F (-12 C)--and never was the same since. I got off on a tangent.

-----
MBP ordered 3/4, est ship 3/27, credit card charged 3/23

[Barefoot Matt]

Originally Posted by paploo

Then again, that battery is kind of toasted anyway... it got too cold--probably about 10 F (-12 C)--and never was the same since.

Wait... exposing the battery to sub-zero temperatures causes permanent damage?? Is that just when it's operational, or can you really not take your laptop to work when it's cold outside?

[volcano]

This is kind of unrelated, but whenever I calibrated my battery on my iBook and woke it from sleep, it took a while for the machine to register the actual life of the battery - it would start off with a ridiculous number like 2 hours and 30 minutes, then eventually crawl up to 5 hours and 30 minutes, with the brightness at 50%, APE on, and BT off. If I remember correctly, it took between 5-10 minutes to show the actual remaining time.

[mintcake]

onlykaria, have you resolved your problem? I'm also getting very short running times on battery from my new MBP, on what I would call a moderate load (no bluetooth, airport, some rosetta apps active for some of the time). I get between two and two and a half hours.

Barefoot Matt, I don't think taking your laptop out in subzero temps is an issue, I have a half-hour hike to the office which I've done in temperatures of -30 and below with a powerbook in my backpack and it hasn't created problems. Your battery will run down much faster in low temperatures, so I wouldn't actually use it in those temperatures, but capacity should rise again once it's fully recharged in an environment with a 'normal' temperature so transporting it around shouldn't be too problematic.

[onlykaria]

Originally Posted by mintcake

onlykaria, have you resolved your problem? I'm also getting very short running times on battery from my new MBP, on what I would call a moderate load (no bluetooth, airport, some rosetta apps active for some of the time). I get between two and two and a half hours.

Barefoot Matt, I don't think taking your laptop out in subzero temps is an issue, I have a half-hour hike to the office which I've done in temperatures of -30 and below with a powerbook in my backpack and it hasn't created problems. Your battery will run down much faster in low temperatures, so I wouldn't actually use it in those temperatures, but capacity should rise again once it's fully recharged in an environment with a 'normal' temperature so transporting it around shouldn't be too problematic.

i took it to the apple store, reset the power something or other, but my batt life is still very poor 1-1.5 hours surfing with airport. its such that i cant take it anywhere without the adaptor... ugh...

[Tomchu]

Get something called "coconutBattery". It will tell you the maximum capacity of your particular battery type, the highest charge that YOUR particular battery has ever held, and your current charge. I don't know the actual max charge for the MacBook batteries (perhaps someone with a functioning setup can let this guy know), but if it's not close to that, demand an exchange.

[amazing]

The major power draws are screen brightness, accessing the HD, and the chip itself. Since you can power-step the chip in system prefs, the main things you can control are screen brightness and reducing HD access.

If you search on versiontracker, you'll see several apps for creating RAM disks (something that was available in OS 9 and was very valuable in prolonging battery life.)

Don't know how good they are, but if you've got something that's constantly accessing the HD, perhaps Filemaker, it should be wonderful (if they've got their bugs worked out.)

There's even a comment on one of the apps about putting a DivX movie in RAM disk, which should really extend the battery life.

Beyond that, it's mainly getting a second battery for those that need long life.

[macboy]

I using my Powerbook 17" 1.5Ghz and that gives me just over 3.5 hours of use, almost 4 with Airport on and BT off using 50% brightness with browsing, installing apps and restarting.

Is that wierd? - I'll take the MBP though =)

[mintcake]

I don't really mind the shorter battery life - I use my laptop at home or near a power socket almost always, and if I'd wanted long battery life I'd have bought an iBook - but I do want the battery life that I should be getting with a new machine. So if I'm getting significantly less than other people with new MBPs, that's a problem.

[inkhead]

how do i turn off one of the cores? I dont' see options like this in energy saver. I always wanted to play around and "tweak" with the cores and performance just to see. Anyway I can do this?

I'm very impressed with the battery life on my macbook pro 1.83/w 2gb of RAM. I ALWAYS leave bluetooth off (makes a big difference for me) but i get 3-3.5 hours if I'm just general use. Which is more than enough.

My latest model 1.67 g4 powerbook with 1.5gb ram gets barely an 1 1/2 hours (and its' new)

[mduell]

Originally Posted by amazing

The major power draws are screen brightness, accessing the HD, and the chip itself. Since you can power-step the chip in system prefs, the main things you can control are screen brightness and reducing HD access.

If you search on versiontracker, you'll see several apps for creating RAM disks (something that was available in OS 9 and was very valuable in prolonging battery life.)

Don't know how good they are, but if you've got something that's constantly accessing the HD, perhaps Filemaker, it should be wonderful (if they've got their bugs worked out.)

There's even a comment on one of the apps about putting a DivX movie in RAM disk, which should really extend the battery life.

I'm not convinced.
An additional 1GB RAM draws ~1-1.5W all the time. The hard drive's power usage increases by about 1.3W only when it's being actively accessed. Using a RAM disk will at best come out a draw, with the generous assumption that you were constantly accessing the HDD without it, and never accessing the HDD with it.

Originally Posted by inkhead

how do i turn off one of the cores? I dont' see options like this in energy saver. I always wanted to play around and "tweak" with the cores and performance just to see. Anyway I can do this?

Downclocking both cores and turning off one core is automatic.

[Tomchu]

You should be convinced.

DRAM is constantly drawing 1-1.5W, because it is being refreshed millions of times a second while your computer is on. A Toshiba MK4025GAS can range from 0.1W (sleeping) to 2.6W (seeking).

Now, I don't know about you ... but given temporary file storage in a RAM disk vs. said Toshiba drive, I'll be saving 2.5W in the best-case scenario (hard drive turned off), and losing nothing in the worst-case. Since my drive will overall be accessed less with a RAM disk, I'll be saving power for sure, but not quite 2.5W.

[mduell]

That's my point; many people have asserted that adding RAM will improve battery life, and I disagree.

Adding another stick of RAM (to provide space for a RAM disk) increases power draw by 1-1.5W, all the time. The hard disk uses ~1W at idle, and ~2-2.5W while reading/writing/seeking. So the difference between having the extra RAM and relying on the disk is the difference between using an additional 1-1.5W all the time vs only using the extra 1-1.5W when reading/writing. No matter how much you access the disk, you can't do better from a power perspective by having more RAM.
Even if you sleep the disk when not in use (and drop to 0.1W), if you're accessing the disk less than half the time without the RAM disk, you're better off accessing the disk than adding the extra RAM.

[Tomchu]

Oh, I see what you're saying. I thought you were talking about this specifically in the context of RAM disks vs. no RAM disk.

However, there's no definite answer for this, unless someone were to do a prolonged study. Consider the amount of disk thrashing that would happen on a power user's system running Tiger with 512 MB of RAM. Now pop in another GB for a total of 1.5 GB. The disk thrashing would all but cease. Apps would all manage to stay in disk cache, and the only time you'd be using the disk would be loading personal files/new, unaccessed apps.

The power savings of that might outweigh the power loss of adding the extra RAM -- but again, a prolonged study would be required.

[inkhead]

Adding more ram = more battery life for me.. We bought several macbook pros for the office and I did the same calibration process on each of them. One has 512mb original, another 1.5gb of ram, and mine with 2gb of ram. I've swamped the batteries all around by my powerbook (with 2gb of ram) always gets about 35 minutes (with a stopwatch) better of battery life.

[mintcake]

Well further tests this evening give me a battery life of just under two and a half hours on a single charge. This is with airport on, bluetooth off, a fair bit of traffic over the network, a half hour or so of heavy work in Rosetta. System Profiler tells me my full charge capacity is 5444 mAh. My system is a 2.0ghz mbp with 2gb RAM and the 7200rpm drive. Should I be booking an appointment at the Genius Bar?

[onlykaria]

Originally Posted by Tomchu

Get something called "coconutBattery". It will tell you the maximum capacity of your particular battery type, the highest charge that YOUR particular battery has ever held, and your current charge. I don't know the actual max charge for the MacBook batteries (perhaps someone with a functioning setup can let this guy know), but if it's not close to that, demand an exchange.

ok my highest charge held is about 85% of the max... hmmm.

[mintcake]

I get 98%, the battery will only hold 5500mAh, apparently. :/

[amazing]

About the efficacy of RAM disks: that's the kind of article that MacWorld used to do under OS 9. And I think it would be an interesting review under OS X--but I rarely expect to find anything interesting in the mag nowadays...

Another great review would be a comparison of wireless signal strength of the MBP compared to the Ti (all sizes), the iBook (both sizes) and a sampling of comparable PC laptops. A number of years ago, there was an article comparing the wireless range of the AEBS to 3rd party WAPS (and the AEBS had about 20% less range than the best 3rd party WAPs). What would be so hard about doing a review of wireless strength? I betcha if they did that comparison, it would increase their readership. But no, every issue is pretty bland, non-controversial.

Similar criticism on the battery front: Apple brazenly displayed prototype MBPs on the SF MacWorld floor, and wouldn't comment on battery life (because at least someone knew that the chip in the floor models was not going to be the shipping chip.)

Even now, months after the intro at SF MacWorld, Apple's spec page still does not list the estimated battery life: Don't they think the buyers might be slightly interested in that little tidbit? Yes, the battery life estimates weren't particularly informative, since they didn't specify the conditions of the tests. But at least there were some figures to agonize over!

[Simon]

OK guys, I think it's time for some hard numbers.

Why don't you just do a

Code:
ioreg -l | grep -i IOBatteryInfo | head -n 1

and report back with the output.

[JKT]

Originally Posted by mintcake

I get 98%, the battery will only hold 5500mAh, apparently. :/

The battery in my PowerBook had a max capacity of 4400mAh (and I would dearly love to get 98% capacity from it again - after two years, it is down to 90% of max capacity when fully charged )

[Simon]

Lucky You!

My 15" 1.67GHz PB went from 4400 to 3600 in 13 months. That's twice your loss in half the time!

[Tomchu]

The second battery that I bought for my 12" iBook G4 also has a design capacity of 4400 mAh, but it holds 4600 mAh. :-D My first battery is still at 4414.

I treat my batteries well.

[jhogarty]

Originally Posted by Simon

OK guys, I think it's time for some hard numbers.

Why don't you just do a

Code:
ioreg -l | grep -i IOBatteryInfo | head -n 1

and report back with the output.

Perhaps I'm doing something wrong, but when I run that command I do not get any output.

J.