LG U400 Service Manual page 69

3. Technical Brief
Trickle charging
When the VBAT is below a certain value, 3.2V, a current generator take care of internal trickle charge
signal is active. The charging current is set to 50mA.
Parameter
Trickle current
Normal charging
When the VBAT voltage is within limits or the internal regulators are turned on, the current source for
trickle charging is turned off and all parts of the charging block are active. The charging method is
'CCCV'. (Constant Current Constant Voltage) This charging method is used for Lithium chemistry
battery packs. The CCCV method regulates the charge current and the VBAT voltage. This charging
method prevents the battery voltage to go above the charge set in the CCCV algorithm. (Fig.3-4-18)
shows the charging voltage(a) and charging current change(b).
(a) Charging voltage
(b) Charging current
Min Typ
30 50
Table. 3-4-9. Trickle charging spec
- 70 -
Max
60
Fig. 3-4-18. CCCV charging method
Unit
mA