Specifications

Smart Battery Charger Specification
SBS Implementers Forum -Page 24- Revision 1.1
6.2. Level 2 Smart Battery Charger Characteristics
6.2.1. Required Commands
AlarmWarning()
ChargingCurrent()
ChargingVoltage()
ChargerSpecInfo()
ChargerMode()
ChargerStatus()
6.2.2. Charge Initiation
Level 2 chargers may initiate charge:
• upon insertion of a battery
• when charge power becomes available
• when ChargingVoltage() and ChargingCurrent() are both set to non-zero values
• when the AlarmWarning() is written without critical error bits set.
Other methods may be used to determine that charging may be (re)initiated. Charging is not initiated if the
Safety Signal indicates that no charging is allowed, if the AlarmWarning() has critical error bits set or when
either ChargingCurrent() or ChargingVoltage() are set to zero. Voltage and current may default at power-
on to the expected open circuit battery voltage and a current ≤10mA.
6.2.3. Charge Termination
Level 2 chargers will discontinue charging:
• when AlarmWarning() is written with critical error bits set
• if either ChargingCurrent() or ChargingVoltage() are set to zero
• when the Safety Signal indicates that no charging is allowed.
Additional methods of charge termination are allowed. Charging may resume when charge initiation
conditions in 6.2.2 are met.
6.2.4. Charge Current and Voltage
The maximum charging current and voltage of the Level 2 charger is determined by the Smart Battery
manufacturer and is programmable through the ChargingCurrent() and ChargingVoltage() commands.
Default values for these may be zero or any non-zero range determined to be safe for any chemistry
(100mA or less). Non-zero default values, if used, must only be enabled when the Safety Signal indicates
that “controlled” charging is allowed. The default charge current and voltage must not be persistent; any
new value of ChargingCurrrent() or ChargingVoltage() must over-write any default values.
6.3. Level 3 Smart Battery Charger Characteristics
6.3.1. Required Commands
AlarmWarning()
ChargingCurrent()
ChargingVoltage()
ChargerSpecInfo()
ChargerMode()
ChargerStatus()
Note that a Level 3 Smart Battery Charger supports all the commands of a Level 2 charger and differs only
in the ability to become a SMBus master device and initiate charging directly. When set to the slave device
mode by the ENABLE_POLLING bit not set, the Level 3 charger behaves in all respects as a Level 2
charger.
6.3.2. Charge Initiation
Level 3 Smart Battery Chargers may initiate charge under the same conditions as Level 2 chargers and
further have the ability to initiate charging under program control. When a Level 3 Smart Battery Charger