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Battery life comparison

H

HardBall

macrumors regular
Original poster
Jan 10, 2006
234
88
I'm deciding among the choice right now, a base model MBA at 13", a rMBP 13" with upgraded core i7 chip, and a baeline model rMBP. Which one of these would hve the best battery life.

Apple store locally said that they all have identical battery life, which sounds a bit incredulous to me. Anyone who has has real life experience with more than one of them?
 
An i7 chip will consume more power than an i5 chip. That is a given. How much may depend on your current task. If both laptops (one with i5 and the other with i7) are put thru the same basic tasks, you won't see a difference in day to day battery usage.

However, if your usage starts to increase when it comes to video manipulation and such tasks, then an i7 will shine most certainly. Of coarse, doing so will decrease battery life with out the power cord faster.
 
jav6454 said:
An i7 chip will consume more power than an i5 chip. That is a given. How much may depend on your current task. If both laptops (one with i5 and the other with i7) are put thru the same basic tasks, you won't see a difference in day to day battery usage.

However, if your usage starts to increase when it comes to video manipulation and such tasks, then an i7 will shine most certainly. Of coarse, doing so will decrease battery life with out the power cord faster.
Click to expand...

The larger models have beefier batteries to compensate for increased power draw. The rMBP 15" has almost twice the battery capacity of the 13" Air, and 50% more than the 13" Pro, which is how they keep the numbers relatively even. I routinely come pretty close to the manufacturer estimates on my Retina 15", and have eked out as long as 9 hours on a charge with brightness down.

Of course, reboot into Windows and it dies in 2 hours. Engaging the GeForce chip kills the battery faster than you can spit.
 
Yes and no. There is a difference between the 15" i5 and 15" i7. There you can't use the size argument.

Also, using the GFX chip is an obvious way of killing your battery all together.
 
jav6454 said:
Yes and no. There is a difference between the 15" i5 and 15" i7. There you can't use the size argument.

Also, using the GFX chip is an obvious way of killing your battery all together.
Click to expand...

I wouldn't expect there to be much difference. They're the same microarchitecture and the same wattage (35W). The i7 only earns that label for clock speed and larger cache.

The quad core i7s take it up to 45W, which is where you get the main difference.
 
Asuriyan said:
I wouldn't expect there to be much difference. They're the same microarchitecture and the same wattage (35W). The i7 only earns that label for clock speed and larger cache.

The quad core i7s take it up to 45W, which is where you get the main difference.
Click to expand...
But on the 15", the battery is also larger, pretty much negating the difference, unless the nVidia chip is being used...
 
Thanks guys;

So I guess the 13" and 15" rMBP are very similar, except when using the discrete graphics.

What about the MBA then?
 
HardBall said:
I'm deciding among the choice right now, a base model MBA at 13", a rMBP 13" with upgraded core i7 chip, and a baeline model rMBP. Which one of these would hve the best battery life.

Apple store locally said that they all have identical battery life, which sounds a bit incredulous to me. Anyone who has has real life experience with more than one of them?
Click to expand...

ill say it again, "they ALL advertise up to 7 hours of wireless web"

you take it how you want to take it. above posts have given many reasons why they are advertised as so.
 
Thanks guys, so it seems that battery life is not much of a ractor in deciding on which machine, all of them are within 1/2 hr if each other according to the experience in this thread.
 
What shortens battery life the most?

So, I've had a rMBP 15" 2.6/16/256 for about four months now. I really like the machine (3rd one as a samsung, others had washed out low brightness LG monitors or IR)

Generally, I get about 4.5-5 hours of battery life. ONCE I got about 6.5 hours battery life. This is really just surfing, 20 pages open in Chrome (although, I use App Tamer to shut down processes most of the time. Connected over a 5gHz network with brightness at about 60-65%.

What can one do to get even better battery life? Is battery life drain driven most by the SCREEN? Is turning the screen down the best thing one can do?

Is turning off WIFI? What about having fewer applications running? I mean this thing is so damb fast one can just open and close most applications at will to save processor cycles. But, even then I'm running at about 2-4% most of the time at MOST.

What about throttling the CPU? Normally, I have the CPU on the integrated CPU and it stays there unless some flash or video spawns that I don't want - at which point I KILL that process and the CPU throttles back.

Im just wondering HOW does apple get "7 hours" Is it at 50% or less brightness?
 
Yes, most battery life tests are done with the screen way down - like 50%. I usually have mine set around 60%
 
tivoboy said:
What can one do to get even better battery life? Is battery life drain driven most by the SCREEN? Is turning the screen down the best thing one can do?
Click to expand...
There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details, including tips on how to maximize your battery life.

The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
 
oh yes

GGJstudios said:
There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details, including tips on how to maximize your battery life.

The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
Click to expand...

oh yes, I've read it several times and implemented many of the great tips that are there. I guess I'm just wondering if there is something else and also trying to truly understand what is the highest drain - so that one could be adjusted if necessary.

I'm going to TRY and do a 50% test just for kicks and giggles to see if I can get to 7 hours
 
So, would pretty mcuh everyone say that the 15 rMBP and the 13" MBP have the same battery life when the 15" runs on the integrated intel 4000?
 
How much of a big difference though comparing the Arrandale models to the discrete and non discrete graphics cards to the Sandy Bridge models same with the graphics card to the Ivey Bridge models.
 
HardBall said:
So, would pretty mcuh everyone say that the 15 rMBP and the 13" MBP have the same battery life when the 15" runs on the integrated intel 4000?
Click to expand...

13" has a 60Wh battery
15" has a 74Wh battery

15" has the greater workload potential, or if workload is kept to the same level as the 13", will have the longer battery life.
 
nando4 said:
13" has a 60Wh battery
15" has a 74Wh battery

15" has the greater workload potential, or if workload is kept to the same level as the 13", will have the longer battery life.
Click to expand...

The bigger Retina screen consumes more power though.
 
B... said:
The bigger Retina screen consumes more power though.
Click to expand...

My bad, Macbook battery specs are

13" cMBP - 63.5 Wh
13" rMBP - 74.0 Wh
15" cMBP - 77.5 Wh
15" rMBP - 95.0 Wh

Apple lists them all as providing "up to 7 hours of battery life". There's certainly going to be variation to that due to the rMBP models having the more power efficient SSDs (HP claims 15% longer battery life due to them), but has more power hungry IPS retina LCDs.

In any case, the 15" rMBP has 22% more battery capacity than the 13" rMBP. The slightly larger LCD will consume more power but the battery will more than make up for it. I'd guestimage the 15" rMBP will see 15% longer battery life than the 13" rMBP when using the iGPU.

To get an accurate representation would require measuring both systems idle power consumption with LCD on then powered off using power management features.
 
nando4 said:
My bad, Macbook battery specs are

13" cMBP - 63.5 Wh
13" rMBP - 74.0 Wh
15" cMBP - 77.5 Wh
15" rMBP - 95.0 Wh

Apple lists them all as providing "up to 7 hours of battery life". There's certainly going to be variation to that due to the rMBP models having the more power efficient SSDs (HP claims 15% longer battery life due to them), but has more power hungry IPS retina LCDs.

In any case, the 15" rMBP has 22% more battery capacity than the 13" rMBP. The slightly larger LCD will consume more power but the battery will more than make up for it. I'd guestimage the 15" rMBP will see 15% longer battery life than the 13" rMBP when using the iGPU.

To get an accurate representation would require measuring both systems idle power consumption with LCD on then powered off using power management features.
Click to expand...

Cool, thats some very useful info. It seems that the 13" might also be slightly more efficient in the microprocessor dpt, due to a lower transistor count part.

Is there anyone who has done a head to head test to see how that shakes out between the two in real life?
 
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