| Address |
Each
device on the bus has one unique seven-bit address.
When a device “sees” its address, it wakes up and responds
to the rest of the command.
Each address is seven bits long with a read/write bit appended
in bit position 0, thus 127 devices are possible with one address
available for a universal address.
To receive a registered address on the bus, a definition of
commands for the particular device class must be submitted to
Intel and approved.
Uses
processing power on the mother board (host) but can use a dedicated
processor (battery). |
|
| |
| APM(Advanced Power Management) |
| A
BIOS interface defined to enable system-wide power management
control via software. |
|
| |
| BIOS |
Short
for Basic Input / Output System.
The BIOS directs the operation of a computer’s resources
such as keyboard input and character display.
Hardware and software contained on a chip.
Older BIOS have to be user set for specific devices (Examples).
Hard drive type, cylinder, size, etc.
Floppy drive type and size.
Memory
size and type.
Newer
computers are “plug & play” where the system recognises
the devices and sets the parameters automatically. |
|
| |
| Calibration
Operation |
Required
process of initialising data for new batteries so that the cell
stack capacity can be learned (Learned Battery Capacity (LBC).
Calibration cycles are also required to account for capacity
variations due to cycling.
As the first part to a valid calibration cycle, the battery
must be charged so that full capacity is assured.
After meeting the full charge criteria, the calibration cycle
remains valid by always satisfying the following conditions:
Battery temperature remains within the window Minimum Calibration.
Temperature (MnCalt) and Maximum Calibration Temperature (MxCalt).
Accumulative
self-discharge is not more than the Maximum Self Discharge (MxSD).
A
partial discharge isn’t followed by a charge.
By
definition, 0% capacity is equal to End of Discharge Voltage
(EODV).
If
valid calibration is met and a discharge brings the battery
voltage to EODV, the calibration cycle is successful and the
Full Charge Capacity is updated. |
|
| |
| Charge
Control |
Circuitry
and firmware that specifies and controls battery charging.
Examples:
Battery
tells charger how to charge (e.g. What voltage, what current,
how long).
Battery
operates as “Master”.
Useful
with dual chemistry chargers (NiMH CC, LiIon CCCV). |
|
| |
| Communication |
Transfers
battery status and data to host device and/or charger.
Examples:
Charge
or discharge mode.
Temperature,
voltage, current alarms (for termination and charge or discharge
control).
Run
time, date, fuel gauge calibration data, cycle number, etc. |
|
| |
| Electronic
Protection Circuit |
Control
circuitry allowing the use of the battery to within safe boundaries.
Primarily found in LiIon batteries.
Examples:
Over-voltage
Under-voltage
Over-current
Over-Temperature
and Under-Temperature. |
|
| |
| EPROM |
Read
Only Memory chip in one of the following types:
OTP
(One Time Programmable) non-erasable.
Windowed
(ultraviolet light erasable) used for prototyping and development
work.
EEProm
(Electronically Erasable Programmable Read-only memory)·
EPROM is re-writable memory that does not lose data if power
is lost to the system (non-volatile). |
|
| |
| Firmware |
Instructions
programmed into a micro-controller that controls its operation.
It
is a combination of hardware (chips and circuit board) and software
(code or programming)
“Minicomputer” that tells what each pin should do.
Capable
of math calculations.
The
firmware changes along with changes to SMBus Specification version
and that also requires a version change number to our programming
or code. |
|
| |
| Fuel Gauge |
The
ability to measure and communicate battery capacity status
Examples:
LED
Or LCD Bargraph on battery·
On screen reading of battery’s state of charge.
On
screen estimate of available run time remaining.
Most
OEMs implement this as a percentage or bar indicator. |
|
| |
| I2C-Bus |
| A
two-wire bus developed by Philips, used to transport data between
low speed devices. |
|
| |
| Master |
A
device capable of independently taking command of the bus and
issuing commands to “slave” devices.
A
Smart Battery can be either a master or a slave.
An
SMBus Host can be either a master or a slave.
A
Smart Battery Charger can be either a master or a slave
A “Master” issues commands to send or receive data.
It can also act as a “slave”. |
|
| |
| MOS-FET
Switch |
Metal
Oxide Semiconductor Field Effect Transistor.
An
electronic component used as a switch to interrupt the current
path (in our use) in a Smart Battery by application of an electronic
signal.
Normally
controlled by the protection IC. |
|
| |
| Non-Recurring
Engineering (NRE) |
| A
one time charge for design and implementation of custom battery
packs. This includes design, hardware, software, assembly and
packaging changes and UL/FCC/CE testing & certification. |
|
| |
| Polyswitch |
Provide
on-battery over-current protection.
Polyswitches are thin polymer devices with low internal resistance
under normal device conditions.
Easily integrated into battery design by welding across cell
terminals or placing on circuit board.
When battery load exceed the trip current of the polyswitch,
the polymer switches to a high resistance state – and holds
until the condition is removed.
Polyswitch then resets to low resistance state (within certain
post trip limits).
Devices have a de-rating at elevated temperatures which means
that they will trip at a lower current if the temperature is
higher – environmental and electrical details of application
must be full understood when designing in polyswitch protection. |
|
| |
| Slave |
A
device capable of receiving commands or issuing information
at the request of a “master”
A
Slave cannot initiate actions nor issue commands.
A
Slave can only accept commands. It can receive data, but only
transfer data when requested. |
|
| |
| Smart
Battery System (SBS) |
Comprised
of the Smart Battery, Smart Battery Charger, and sometimes the
Smart Battery Selector.
Acts to deliver data about the Smart Battery’s state-of-charge,
remaining run-time, remaining time to full-charge.
Allows the Smart Battery to control its own charging characteristics,
as well as allowing multiple Smart Batteries to coexist in one
system. |
|
| |
| Smart
Battery Charger |
| A
battery charger that periodically communicates with a Smart
Battery and alters its charging characteristics in response
to information provided by the Smart Battery. |
|
| |
| Smart
Battery Charger Specification |
Defines
a set of commands that a smart charger (i.e. software-programmable
charger) must understand and implement
The smart charger allows the battery to control its own charge.
This capability is fundamental to the concept of chemistry independence,
which means that the charging algorithms are contained in the
battery rather than in the charger hardware.
Smart
charger notebook computers allow users to be able to buy replacement
smart batteries with the latest refinements in battery technology,
as long as the battery fits in the notebook cavity. |
|
| |
| Smart
Battery System Specification |
Defines
the messages that flow between the components of the Smart Battery
System (Smart Battery, Smart Battery Charger, and Smart Battery
Selector)
SBS
Specifications define:
Communication
Bus
Smart
Battery data set
BIOS
interface
Charger
commands
Multi-battery
selector commands
Defines
data points (data set) and protocol (the timing and voltage
level of the bits in a command) that an SBS-compliant battery
must be able to report to the master device (a charger or computer
host).
SBS
Specifications provide information for:
The
OEM and end user
The
power management software
The
Smart Charger
Enables
co-ordination of the smart battery elements at the computer
system level
Allows
batteries of different capacities or chemistries or from multiple
suppliers to “speak a common language” to contribute
to system power management
Is
not currently set up to accommodate other operating systems
such as Macintosh, Java, etc. |
|
| |
| Smart
Device |
An
electronic device or module that communicates over the SMBus
with the SMBus Host and/or other Smart Devices.
For
example, the back-light controller in a notebook computer can
be defined as a Smart Device. |
|
| |
| SMBus
(System Management Bus) |
A
specific implementation of an I2C-bus that describes data protocols,
device addresses and additional electrical requirements that
is designed to physically transport commands and information
between the Smart Battery, SMBus Host, Smart Battery Charger
and other Smart Devices.
A
system using SMBus passes messages to and from devices instead
of using individual control lines which reduces connector pin
count.
With
SMBus, a device can provide manufacturer information, tell the
system what its model/part number is, save its state for a suspend
event, report different types of errors, accept control parameters,
and return its status
A
device on the bus can be either a master and issue commands
or a slave and only accept commands or requests for information. |
|
| |
| SMBus
Host |
A
piece of portable electronic equipment powered by a Smart Battery.
It is able to communicate with the Smart Battery and use information
provided by the battery. |
|
| |
| Thermal
Fuse |
One
shot fuse to remove the battery from the circuit if an extreme
over temperature condition exists.
Typically set at 93DegC.
Fuse cannot be reset and battery must be disposed of if the
fuse blows. |
|
| |
| Thermistor |
Thermistor
is a temperature sensitive resistor·
Its resistance may increase or decrease with temperature based
on the type of thermistor being used.
An NTC (negative temperature coefficient) thermistor resistance
decreases with increase in temperature, while a PTC (positive
temperature coefficient) thermistor resistance increases with
increase in temperature.
NTC thermistors are most commonly used in batteries for temperature
sensing.
A thermistor in a battery plays a very important role.
Sometimes this is the only means of communication between the
battery and the external world.
It can be used by the charger to determine starting environmental
conditions and prevent charging if the battery temperature is
too low or too high.
It may be used to terminate charge (dt/DT) or disconnect the
battery from the host in an over-temperature condition (MaxT).
In
a smart battery there may be more than one thermistor.
One
could be used for temperature measurement by electronic assembly
inside the pack.
A
second could be used as a stand alone interface to the external
world.
Different
thermistors may be used to identify the battery chemistry.
E.g. In
our NJ1020/NI2020 standard batteries, a 10K thermistor is used
for NiMH and a 300 ohm fixed resistor is used for Li-Ion. |
|
| |
| Thermostat |
Mechanical
switch to remove battery from charger or load if an over temperature
condition exists.
Contacts
closed during normal battery operation.
Contacts
open if cell surface temperature reaches thermostat calibrated
temperature (typically +70DegC).
Thermostats
have a hysterisis whereby the contacts close after a significant
temperature drop to reduce “cycling” of contacts.
Opening
temperature will reduce under higher current operation – this must be accounted for when designing the system. |
|
| |
