How many hours of battery life do you get from your 13" mbp?

[notjustjay]

Somebody told me that at the late hours of the night, Macs perform a self maintenance. Cleaning out caches, storing files, managing ram. Is this true? If so, is Apple really so thoughtless to think that maybe some people turn their computers off every night thus eliminating the possibility of the machine EVER doing maintenance?

Yes it does. You can do it yourself:

http://www.thexlab.com/faqs/maintscripts.html

 

[MrCheeto]

Yes

I suppose, then, that is also a response to:

"is Apple really so thoughtless to think that maybe some people turn their computers off every night thus eliminating the possibility of the machine EVER doing maintenance?"

 

[notjustjay]

I suppose, then, that is also a response to:

"is Apple really so thoughtless to think that maybe some people turn their computers off every night thus eliminating the possibility of the machine EVER doing maintenance?"

Well, I'm not so sure that I would want it doing those things when I'm trying to work on the machine. I suspect, however, that (a) most people do not leave their Macs on 24/7, and (b) given that I've never heard of any problems resulting from not doing this maintenance, that it's not that important.

What I don't know, is whether or not this maintenance happens when you log in or our or startup or shutdown the computer. It would make sense to me to have these tasks done at those times.

 

[macjunk(ie)]

No...my MacBook Pro sometimes lasts eight hours during the lightest internet use...

Somebody told me that at the late hours of the night, Macs perform a self maintenance. Cleaning out caches, storing files, managing ram. Is this true? If so, is Apple really so thoughtless to think that maybe some people turn their computers off every night thus eliminating the possibility of the machine EVER doing maintenance?

yup..it is true...find more info here

i anyways use onyx to perform maintenance once in two weeks....so i guess it should be okay

 

[Pax]

I do this almost four or five times a day.

2.53ghz:
Brightness two notches from maximum
Safari, iChat, Mail, Skype running
WiFi enabled
Usually using about 5-20% CPU

Battery life = 5-7 hours.

I'm curious about this because I really couldn't get 7 hours just leaving the thing idle with no software open. Looking in System Profiler I see a Full Charge Capacity of 5200 mAh. With this setup:-
- 2.26 GHz
- Safari & Mail only
- Brightness 2 notches from maximum
- WiFi on
my Mac is saying "Amperage: 1090 mA" more or less and it says about 5 hours which is all consistent. I couldn't get 7 hours though.

Can you copy-paste your System Profiler "Power" page onto here, I'd like to see what your numbers

Even if I turn brightness to 1 notch from bottom and turn airport and keypad lighting off, I only get down to 740 mA. Then I add stuff in...
WiFi +110 mA
Keyboard +70 mA
Brightness 2 notches from top, +230 mA

 

[Cool Runnings]

yup..it is true...find more info here

i anyways use onyx to perform maintenance once in two weeks....so i guess it should be okay

Isn't most of this solved by a reboot once in a while? Maybe throw in a safe reboot?

 

[jkozlow3]

I tested the battery life on my 13" MBP last night.

Usage Conditions:
Screen brightness exactly in the middle
Keyboard illuminated but on the lowest setting (1 tick)
Mail.app open but not really using it aside from whatever new emails came in on their own.
Using Firefox and surfing the web over wifi constantly during the test
No other activity

My battery percentage (as displayed in the menu bar) dropped almost exactly 10% every 30 minutes or 20% per hour. I watched it very carefully over a 2 hour period as it went from 100% > 60%. At this point I plugged my MacBook back in and concluded that I should get right around 5 hours of battery life.

Seems about normal given my usage conditions and considering the advertised 7 hours is probably a theoretical maximum, no?

 

[notjustjay]

Seems about normal given my usage conditions and considering the advertised 7 hours is probably a theoretical maximum, no?

If you dropped your screen brightness to 1 or 2 ticks, turned off wifi and bluetooth, and did little else but type, you could probably get 7+ hours.

It might sound like an unrealistic scenario but imagine packing the laptop to take notes in classes or seminars all day in a darkened lecture hall.

 

[Pax]

Right. Spot on guys. That's what i get too. 5 hours in normal usage scenario, you could probably just about squeeze 7 hours, but you would have to turn everything to minimum and leave it on the shelf. You couldn't really DO anything useful unless you were in a dark room with an Ethernet cable.

I'm still intrigued by MrCheeto who claims to get 7 hours with brightness from maximum. He must know something we don't

 

[MrCheeto]

Maximum? Maybe just a tick or two past half. All I know is I put the notebook in the kitchen at 8am to eat breakfast and start working on the machines on the table there and didn't have to put it back in my room until after 1pm.

 

[Pax]

Maximum? Maybe just a tick or two past half. All I know is I put the notebook in the kitchen at 8am to eat breakfast and start working on the machines on the table there and didn't have to put it back in my room until after 1pm.

That's more like it - 5 hours or a bit more with brightness just over half. Consistent with what we all see. But you originally said 5-7 hours with brightness 2 ticks from maximum, which I don't think is possible.

 

[NT1440]

Usually around 6.5 from just browsing and word processing. I've noticed Itunes drops the estimate lower, but doesn't seem to have a big impact on the real time usage.

I keep my screen one tick below midway.