Charging Operation; Battery; Charging Circuitry - Nokia RH-3 Series Troubleshooting - Bb

RH-3
Troubleshooting — BB

Charging operation

Battery

In RH-3, a Lithium-Ion cell battery with a capacity of 850 mAh is used. Reading a resis-
tor inside the battery pack on the BSI line indicates the battery type and size. The tem-
perature sensor for BTEMP is inside the phone and position on the board in a way that it
always has the same temperature as ther battery itself.
Temperature and capacity information are needed for charge control. The resistor for
capacity info is connected to BSI pin of battery connector. Phone has 100 kΩ pull-up
resistors for this line so that they can be read by A/D inputs in the phone.
See Figure 13 on page 18 and Figure 14 on page 18 for the details.

Charging circuitry

The UEM ASIC controls charging depending on the charger being used and the battery
size. External components are needed for EMC, reverse polarity and transient protection
of the input to the baseband module. The charger connection is through the system con-
nector interface. The RH-3 baseband is designed to support DCT3 chargers from an elec-
trical point of view. Both 2- and 3-wire type chargers are supported. For the 3-wire
charger, the control line is not supported and not connected to the Baseband ASICs. See
Figure 15 on page 19 for details.
Page 18
Figure 13: BL-5C battery pack pin order
Figure 14: Interconnection diagram inside the battery pack
Nokia Corporation
CCS Technical Documentation
Confidential Issue 1 06/2003