Why are batteries not getting improved on devices?

Are they not getting better, or are the hardware they're powering taking up more energy, which makes it seem like the technology is not moving forward

Unfortunately there is only so much space for batteries. And I don't think there is a better technology of them then Lithium Polymer batteries. Maybe if we found even more efficient ways to process data, we could get better battery. Additionally, if different screen and drive technologies emerge that use even less power we could see better battery life. For now, it might just be seeing how much power we can get with keeping about the same battery. Apple likes doing that. They get all these different screens and CPUs yet on the MacBook pro they maintain the 7 hour battery life. I think once we cap our processor capabilities we'll look at making the devices last longer on a charge.

There is a huge improvement for battery life. The only reason why you don't is because our devices are limited to our batteries.

Example:

1. Current phone with all the basics lasts 8 hours.

2. Hype on new phone's battery says it will last 12 hours with all the basics.

3. Now that the battery is better, NFC and Virtual Reality are added to the new phone

4. New phone you receive now has 2 added features and the battery only lasts now 8 hours.

Meaning each time we improve the battery we stuff in more features which uses more of the battery.

with batteries, they have not had much improvement over the past 10 years.

Batteries have a simple way of telling how good they are, first they tell you the capacity, then they well you the lifespan of the battery (eg some are rated for 300 recharges, and others are rated for 500+ charge cycles.

The main issue is that capacity has not gone up by much. (The batteries from my old PDA's have similar capacities to the batteries in modern devices with similar sized batteries)

the most that seems to have happened is the endurance of the batteries have gone up by a little, the one on my old HP and dell PDA's are rated for 500 charge cycles, and the one in my mytouch 3g slide is also rated at 500 cycles but the mytouch has a different capacity loss curve. the one on my old PDA has an almost linear drop in capacity as you recharge while the battery in the mytouch 3g slide has lower slope then near the end if falls off rapidly, to while my PDA's battery may handle 500+ charge cycles, when you start to get near around 400 cycles, the battery life is too short to use probably around 40% or so of it's original capacity), while with the newer battery, at around 400 cycles, the battery is still holding around 65-70% or so of it's original capacity

over the years, there has not really been any increase in the energy density of the batteries.

While there are newer battery technologies such as super capacitors which allow things such as 500,000+ charge cycles with no loss in capacity http://en.wikipedia.org/wiki/Electric_double-layer_capacitor

http://batteryuniversity.com/learn/article/whats_the_role_of_the_supercapacitor/

the issue with those is that the energy density is pretty low compared to a li-ion battery, so to effectively use one, it will bring cellphone sizes to how they were in the 80's just to give the same battery life that we have now. eg something like that but with an iphone screen http://i.imgur.com/c6YpQ.jpg

(the benefit of super capacitors is that they can be charged much faster with little to no charge reduction near the end of the charge cycle, they can also be discharged rapidly with almost no heat issues, so you can do something like use something to step up the voltage and power a tazer directly, or other rapid discharge scenarios

Any time there is an improvement in battery life the devices become more demanding. I think to go further battery technology will have to change. The day when we can tale for two days in a row could be handy.

Do you not think if it was easy to make major improvements in batteries somebody would have done it by now? Basic science. There are only so many substances in the world and even fewer of them that have the necessary qualities (and indeed quantities) for battery production. Unless somebody stumbles upon a 'super element' batteries have gone pretty much as far as they can go especially given the constraints of the space available for them. Until somebody comes up with cold fusion or warm superconductivity portability comes at the cost of a limit on use.

Batteries are a very complicated thing in real life for engineers. Here are some factors to concider:

1. How much constant current can I get?
2. How much instantaneous current can I get?
3. What is the drain curve like, some batteries will gradually fall in voltage, some stay level but then drop quickly.
4. Can we ship these? LiIon and LiPoly batteries cannot be shipped on planes in many countries.
5. Can you draw small currents?
6. Shelf life
7. How does it behave to different temperatures

Here is an example, Lets say you have a device that is in sleep mode most of the time. It pops up once and a while, does something quick, then goes back to sleep.

In this case you need a battery that will supply a small current, some batteries don't behave nicely when you only want a few nanoamps. But lets also say when you get up to do things you draw a lot of current right away and you continue to draw lots of current until you finish. You need a battery that will respond quickly to the current change and maintain that current for a while.

Most batteries don't gradually fall from 3.3V (typical) to 0. Here is a generic example: http://www.analog.com/library/analogDialogue/archives/35-04/touchscreen/FIG_07.gif

there are many more examples but point is that batteries are not that simple, and there is a lot that goes into them. People are making better batteries, it just takes time.

It is, but you don't notice it because the rest of the hardware uses the extra power.

For example; I have a 2009 MacBook Pro - with a Core 2 Duo CPU and nVidia 9400M Graphics. It had 7 hour battery life when it was new.

If you look at a current generation MacBook Pro - it has a Dual Core i5 CPU with Intel HD 4000 Graphics. Clearly it has much more powerful graphics and processing power, therefore using more power than my 2009 MBP - yet THAT has 7 hours battery life too.

Even the new MBP with Retina Display - running an above 1080p resolution with nVidia GT 650M, and using a Quad Core i7, gets 7 hours battery. It does have more space to fill with batteries, but still, it has a higher power output than 3 years ago.