WM_PRJ_Q2400_PTS_005 -007
18th January 2006
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2.4 Battery charging interface
The WISMO Quik Q24x6 sub-series module has a battery charging interface.
The table below summarizes the battery types supported according to the
software version:
Battery types supported versus software version
Battery type
OS version
Before X55
X55 and after
Ni-Cd Supported
Supported
Ni-Mh Supported
Supported
Li-Ion Not
Supported
Supported
Warning:
Charging a Li-Ion battery with an OS version prior to X55 may cause damage
to the battery.
This circuit uses an interface which consists of a current source inputs (CHG_IN)
where the constant current has to flow in order to charge the battery.
This current value depends on the battery capacity. It is recommended to
provide a current equal to the value of the capacity plus 50 mA. For a 550 mA
battery the current will be 600 mA. The maximum current is 800 mA.
The WISMO Quik Q24x6 sub-series module monitors the battery voltage to
detect the end of the charge.
It also monitors the temperature of the battery (for security reasons) through the
BAT_TEMP pin which has to be connected to a temperature sensor inside the
battery pack (an NTC resistor for instance).
Typical Implementation:
Safety
Circuit
NTC
GND
BAT_TEMP
+VBATT
R1
C1
VCC
Internal Battery
Impedance
BATTERY
Figure 19: Example of battery implementation
