User Guide

RH-27
System Module CCS Technical Documentation
Page 8 © 2003 Nokia Corporation Confidential Issue 1 11/2003
Figure 1: Battery pack contacts
The BSI fixed resistor value indicates type and default capacity of a battery. NTC-resistor
measures the battery temperature.
Temperature and capacity information is needed for charge control. These resistors are
connected to the BSI and BTEMP pins of the battery connector. Phone has 100 kW pull-
up resistors for these lines so that they can be read by A/D inputs in the phone. For safety
Table 1: BLD-3 characteristics
Description Value
Nominal discharge cut-off voltage 3.1V
Nominal battery voltage 3.7V
Nominal charging voltage 4.2V
Maximum charger output current 850mA
Minimum charger output current 200mA
Cell pack impedance -20 ... 0
o
C
180mΩ max
Cell pack impedance 0 ... +20
o
C
150mΩ max
Cell pack impedance +20 ...+60
o
C
130mΩ max
Cell pack impedance +60 ...+80
o
C
250mΩ max
Table 2: Pin numbering of battery pack
Signal name Pin number Function
VBAT 1 Positive battery terminal
BSI 2 Battery capacity measurement (fixed resistor inside the
battery pack)
BTEMP 3 Battery temperature measurement (measured by ntc
resistor inside pack)
GND 4 Negative/common battery terminal
Char
ge
GND
2(BSI) 3(BTEMP) 4(GND)