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15" Albook battry experiment

Kingsnapped

Kingsnapped

macrumors 6502a
Original poster
Oct 16, 2003
929
3
Los Angeles, CA
Hey, I just got my 'book on monday, and I'm loving it. No white spots (yet..) only one dead pixel and great performance. My only gripe is with the battery. It's not going too far, and I'm wondering if mine is abnormal. You could help me out by going to the terminal and finding your battery's capacity. Enter

ioreg -l -w 0 | grep IOBatteryInfo

and post the capacity. Mine is at 4613, and I need to know if I should shoot for a replacement when I go to the Milwaukee Apple store on Sunday. Thanks much.
 
What is "normal" capacity for a 15" Al PB. I've got one at home and will check it when I get back tomorrow. But just so I know when I check before I post.
 
I've got two 15" Al powerbooks, and when they arrived they were both around 4550 mAh. If you look at page 73 of the user guide, you'll see that the battery should be rated at 4600 mAh. So, it looks like you're withing spec. However, I'm interested to see that happens when you apply the recent battery update and then run it through a calibration charge cycle. Both of my batteries dropped to 4400 mAh. It's still a little annoying though, for some reason the battery updater dropped the capacity of my batteries...
 
I never got around to reading the user's guide past calibrating the battery. I really should get around to that.

Funny thing is, I was getting really poor charge times. I downloaded and installed all of yesterday's updates, and nothing changed. Right after I made my last post today, I unplugged it from AC power and the other monitor, for some reason, it wouldn't start up and made me do a hard restart. When it booted up, my charge was around 96% (after being plugged in a few hours) and I had about 3:30 of battery life. That's two full hours more than what I was getting on a full charge! I don't know if it'll actually hold true, but I have x-charge running to keep track for me.

Laptops are wierd...
 
Originally posted by isd_glory
I've got two 15" Al powerbooks, and when they arrived they were both around 4550 mAh. If you look at page 73 of the user guide, you'll see that the battery should be rated at 4600 mAh. So, it looks like you're withing spec. However, I'm interested to see that happens when you apply the recent battery update and then run it through a calibration charge cycle. Both of my batteries dropped to 4400 mAh. It's still a little annoying though, for some reason the battery updater dropped the capacity of my batteries...
Click to expand...

Same findings here. Before battery update it read 46xx, but after the upate it´s never been above 4400. I also find that the power meter is inaccurate. If I use the machine for browsing, and browsing only, it´ll last a good 15 minutes after it has reached 0:00...

-KJ
 
Battery Capacity Reading

Sorry I need some clarification on this. I typed in ioreg -l -w 0 | grep IOBatteryInfo and received a capacity reading of 3225 for my 12" Powerbook Rev A.

According to the tech specs this Powerbook has a 47 watt hour battery. Does this mean my battery is a dud???

Your help is appreciated
 
Your battery's performance in Watt Hours can be found by multiplying the capacity (Amp Hours) by the Voltage (Volts). In the information from IOreg, 3225 is 3.225 Amp Hours. Assuming that your computer is pulling about 12 Volts, that only works out to 39 Watt Hours. That battery would be below spec, but its unknown if its in bad enough condition for apple to replace it.

Peronsonally, I dont like this battery update. Not have I apparently lost some capacity, but I feel that this update is more "cosmetic" than anything else. After applying the update, almost everyone seems to be getting capacities of exactly 4200 or 4400 mAh. One of my batteries used to be 4550 wihle the other was around 4500. Given the vast number of batteries and slight manufacturing differences, fixing a capacity to be lower or higher than the battery's true capacity will only caluse trouble in the long run. I just find it doubtful that all our batteries are now "equal" just because we all have the same reported capacity.
 
If you haven't yet, try applying the battery update.

My capacity went fro 3800 to 4200, with an apparent corresponding increase in actual life.

There appears to have been a bug in the battery firmware that is underreporting the capacity.

Oh, and as for that 4600 battery that started this thread -- instead of complaining, guard that battery with your life!

That's on the high end of what people have managed to get out of their batteries!
 
Originally posted by isd_glory
After applying the update, almost everyone seems to be getting capacities of exactly 4200 or 4400 mAh. ... I just find it doubtful that all our batteries are now "equal" just because we all have the same reported capacity.
Click to expand...

I suspect that they are back to the "default" setting, and will need to be recalibrated.

Once the recalibration is done you will once again see variations.
 
Battery Capacity Reading

Thanks for explaining the formula to me. I will have to have a chat to Apple.

Since my failed updates to 102.8 (twice - once on the original 10.2.8 and also on the current 10.2.8). I've always suspected my battery was somehow holding less charge than it used to be. Until now I've never been able to point to any hard data evidence to disprove their assertions that my battery usage was still witihin their acceptable range.

By the way I haven't really noticed any significant change with the battery update patches.
 
Once the recalibration is done you will once again see variations. [/B]
Click to expand...

Actually, both of my batteries have been recalibrated. I was amazed that they have stayed at a steady 4400. If anything, it looks like the battery update may have set an upper limit...
 
Originally posted by isd_glory
Actually, both of my batteries have been recalibrated. I was amazed that they have stayed at a steady 4400. If anything, it looks like the battery update may have set an upper limit...
Click to expand...

That could be. Maybe also they've reduced the "sensitivity" so it rounds to the nearest 100.

That would probably cut back on some of the tech support calls ... "My friend's battery reads 4206, and mine's only 4204! I demand a replacement so I can get the same life as his!"
 
Yeah, that's what I figured. If you have ever been over at the Apple's own discussion forums, there is always someone trying to make the claim that apple somehow cheated them out of like 0.050 Amp Hours of battery life. Even so, I liked having an accurate reading of battery capacity for diagnostic reasons. When it starts falling its time to get a new battery.

Still, I'm kinda curious as to what happened to the almost 0.2 Amp Hours of battery life that I had before this update...
 
mines only 4141, and im often lucky to get 2.5 hours on only web surfing and aim chat
 
Oh, and as for that 4600 battery that started this thread -- instead of complaining, guard that battery with your life!
Click to expand...

My reading up there might have been a mistake. That was right after the battry update, and with no calibration. I'll try agian the next time I run it to the bitter end.

I know nothing about my laptop's battry, I was just worried that mine was different or poorer than the norm.
 
Weird.

I let my battery run down to the point where the machine refuses to start without the charger plugged in. Started charging, and now it reads 4575? :confused: What is going on? Anyone know what the design capacity is? On my old laptop my battery would overshoot the design capacity by 1.2Wh if I cycled full depletion / full charge a couple of times.

-KJ
 
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