HANSONG HSBT3031-08, User Manual

Page: 19 / 34

HSBT3031-08 module_datasheet Version2.0– Jun. 15 th
HANSONG ( NANJING) TECHNOLOGY CO.,LTD
19
Fast charge
Fast charge has two parts:
■
Constant current: Entered when VBAT is sensed in the range Vfast to Vfloat point (C). This
is the maximum charge rate, and should be set according to the battery manufacturers Data
Sheet.
■
Constant voltage: When Vfloat is reached the cell voltage is maintained at Vfloat, and the
current slowly reduces until the termination point (E) is reached where charging ceases, and
the charger transitions to Standby mode.
Vfloat can be configured from 3.65 V to 4.40 V in 50 mV increments. This allows use of cells
with different Vfloat values, or cell life extension by reducing Vfloat. Vfloat can also be altered
depending on temperature change, for cell life protection.
The current termination point (E) can be adversely influenced by dynamic changes in VBAT
load current, or to a lesser extent changes in VCHG voltage.
Parameters in Fast charge
Standby mode
Once the charge current has fallen and the charger is terminated, the system enters Standby
mode. In Standby mode, the charger does not charge. It continues to monitor the battery
voltage. If the voltage falls back below Vfloat
by more than a configurable threshold Vhyst, point (D), then the charger re-enters Fast charge
mode. Vhyst is expressed as a percentage of Vfloat.
In this way, the charger system maintains the cell near full charge while prolonging cell life.
Parameters in Standby mode