power battery 3

7/31/2019 Power Battery 3

1/34

Power and Battery

Technology

Thuyen Ngo


2/34

Outline

Power technology

Battery technology

8/23/2012 2


3/34

Power technology

Power consumption analysis

Micro benchmark (physical level)

Macro benchmark (application level)

Power management schemes

8/23/2012 3


4/34

Power consumption

Micro benchmark

Idle

Peak

8/23/2012 4


5/34

Suspended State

8/23/2012 5


6/34

Idle State

8/23/2012 6


7/34

Display

8/23/2012 7


8/34

CPU and RAM

8/23/2012 8


9/34

Flash Storage

8/23/2012 9


10/34

Network

8/23/2012 10


11/34

GPS

8/23/2012 11


12/34

8/23/2012 12


13/34

Power consumption

Macro benchmark (application levels)

Video

Phone call

SMS

Email/Web

Advertising applications

8/23/2012 13


14/34

Audio playback

8/23/2012 14


15/34

Video playback

8/23/2012 15


16/34

Phone Call

8/23/2012 16


17/34

SMS

8/23/2012 17


18/34

Email

8/23/2012 18


19/34

Ads in free apps

Tailing: app fails to close its connection to the

internet.

Energy Accounting in apps design!

8/23/2012 19


20/34

Ads in free apps

8/23/2012 20


21/34

Power management

Hardware

Separate low-power core active at power saving mode

Tegra 3: SoC with quad-core CPU, but includes a fifth

companion, low-power core.

Software

Undervolting

Reduce the voltage of the processor and reduce the power

consumption accordingly

Smart battery: making applications adaptive to the

amount of energy left in the battery

8/23/2012 21


22/34

Power management

Software:

Energy-efficient apps design

Energy waste awareness

GUI: predict user interaction and time

TCP based energy saving

User awareness:

Bluetooth, GPS, Wifi and 3G

8/23/2012 22


23/34

Power technology

Sum it up:

Which part the phone uses the most energy?

What kind of applications/connections would

quickly drain the battery?

Nettail?

Power management schemes?

8/23/2012 23


24/34

Battery Technology

Why we care?

Common batteries for mobile devices

State of the art

8/23/2012 24


25/34

Battery Technology

Why we care?

Simply we need energy for mobility

Computation power has been dramatically

increasing (Moors law)

Battery development does not obey Moors law


26/34

Battery

Basic properties:

Recharge-ability: basically, when the direction of

electron discharge (negative to positive) is

reversed, restoring power.

Memory Effect: (generally) When a battery is

repeatedly recharged before it has discharged

more than half of its power, it will forget its

original power capacity.

8/23/2012 26


27/34

Battery types for mobile devices

Nickel-cadmium: (NiCd)

rechargeable,

memory effect

Nickel-metal hydride:(NiMH)

rechargeable

nomemory effect

Lithium-Ion: (Li-Ion)

rechargeable

nomemory effect

Lithium-Ion-Polymer:(Pi-Poly)

rechargeable

nomemory effect

8/23/2012 27


28/34


NiCd - Nickel Cadmium

Use nickel oxide hydroxide and metallic cadmium aselectrodes.

Require frequent charging and not environmentalfriendly

Require full discharge/charge to reduce memoryeffects

Usage: laptop batteries

NiMH - Nickel-metal hydride

Same structure except without Cadimium

8/23/2012 28


29/34

Li-Ion

High energy density means greater power in asmaller package.

160% greater than NiMH

220% greater than NiCd

Strong current allows it to power complexmechanical devices.

only 5% discharge loss per month.

10% for NiMH, 20% for NiCd

8/23/2012 29


30/34

Li-Poly

Li-ion uses cylindrical cells which required

rigid structure to hold cells.

Li-poly uses pouch cells which only needs

polymer case

Results: Li-Poly offers the attributes of the Li-

ion in ultra-slim geometry and simplified

packaging. Main applications are mobile

phones.

8/23/2012 30


31/34


8/23/2012 31


32/34


8/23/2012 32


33/34

State of the art

Lithium-poly battery

Thin-film battery (lithium-ion + nano-tech)

8/23/2012 33

Extremely

small size

offers much

more power

density


34/34

State of the art

Beyond battery: Battery + Fuel cell

8/23/2012 34

power battery 3

Documents