I65/I56I HARDWARE DESCRIPTION VERSION
1.00
Figure 8:
Battery pack circuit diagram
5.6.3 Recommended battery pack specification
Nominal voltage
3.6 V
Capacity
800 mAh
NTC
10 k
Ω
± 5 % @ 25 °C, B (25/85) = 3435K
± 3 %
Overcharge detection voltage
4.325 ± 0.025 V
Overcharge release voltage
4.075 ± 0.025 V
Over discharge detection voltage
2.5 ± 0.05 V
Over discharge release voltage
2.9 ± 0.5 V
Over correct detection
3 ± 0.5 A
Nominal working current
<5 µA
Current of low voltage detection
0.5 µA
Over current detection delay time
8 ~ 16 ms
Short detection delay time
50 µs
Over discharge detection delay time
31 ~ 125 ms
Overcharge detection delay time
1 s
Internal resistance
<130 m
Ω
Table 12:
Battery pack specifications
5.6.4 Implemented charging technique
If the external charging circuit follows the recommendation of
charging process consists of trickle charging and processor controlled fast
charging. For this solution, the fast charging current provided by the charger or
any other external source must be limited to 500 mA.
5.6.4.1 Trickle
charging
Trickle charging starts when the charger is connected to the charger input
of the external charging circuit and the module’s POWER pin. The
charging current depends on the voltage difference between the charger
input of the external charging circuit and VC5+ of the module.
Trickle charging stops when the battery voltage reaches 3.6 V.
5.6.4.2 Fast
charging
After trickle charging has raised the battery voltage to 3.2 V within 60
minutes
±
10 % from connecting the charger, the power ASIC turns on
and wakes up the base band processor. Now, processor controlled fast
charging begins. If the battery voltage was already above 3.2 V,
processor controlled fast charging starts just after the charger was
connected to the charger input of the external charging circuit and the
POWER pin of module. If the GSM/GPRS part of the I56/I56i was in
POWER DOWN mode, it turns on and enters the Charge-only mode
along with fast charging (see also chapter
Fast charging delivers a constant current until the battery voltage reaches
4.2 V and then it proceeds with varying charge pulses. As shown in
, the pulse duty cycle is reduced to adjust the charging procedure
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