Battery life and thin laptops

[Karl Mose]

Hey there everybody, just a question I've pondered for some time. How come something like the Macbook air can keep up to 12 hours of battery life, while much bigger laptops with only marginally faster hardware struggle to even keep it at over three? Ultrabooks seem to champion the battery life of windows laptops, but they're the thinnest at the same time, wouldn't the lack of extra space suggest that they couldnt fit a bigger battery in the laptop?

I mean how often do you see af 17" laptop with even a slightly mobile battery life? I know there's a lot more screen to power, but their hardware often doesnt differ from the hardware in smaller laptops, so you should think they would use the added room for a gigantic battery? Also, why doesnt companies take the hardware of an ultrabook that's under 1,5 cm thick, and just add a whole new layer to the laptop that's just one big battery with a height of around 1cm? It would still be smaller than a lot of other laptops, but it should offer otherworldly battery life, right?

I'm assuming all this is wrong, but I don't know how, so that's why I'm asking. I'm not an expert on these things, so be patient with me

 

[Alabalcho]

That 17" laptop has twice the LCD side ot that Macbook, i7 processor for your games, and hungry GPU (apart from dual hard-drives).

Macbook Air was designed with long battery in mind; 17" laptop is "desktop replacement", not "road computing"

 

[Prostar Computer]

There are quite a few things to consider about this question, but it is a reasonable question.

1. Macbooks, as far as I know, use Lithium Polymer batteries. While they yield similar performance to Lithium Ion, this is more for what allows for a slimmer profile. More info on the two are here: http://batteryuniversity.com/learn/article/is_lithium_ion_the_ideal_battery

2. The MBA uses a very, VERY limited CPU. It comes stock with an ultra low voltage i5, and can be upgraded to a severely limited i7. Without going too much into the electrical details, these processors are designed to put out less heat and draw less power at the expense of notably reduced performance. "Marginally faster," therefore, is something of an understatement. These specifications are what greatly increase battery life per cycle on MBs and other notebooks touting a ULV processor.

3. The size of the battery isn't the sole determinant of its efficiency and life per charge/discharge cycle. The larger the battery, the more room for heat, more overhead for [additional] cells, etc. That battery university site has a lot of in depth information you can peruse, if you're really interested.

Hopefully that's a start.

 

[Karl Mose]

Thanks Prostar! Sorry for the late answer but apparently Toms email system didn't work for me. You explained it very well though!