User Guide

CCS Technical Documentation System Module
RH-25
Issue 1 10/2003 ©Nokia Corporation Confidential Page 9
Figure 2: 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 BSI and BTEMP pins of battery connector. Phone has 100 kW pull-up resis-
tors for these lines so that they can be read by A/D inputs in the phone. It should be
noted that the phone software will shut the phone off if it senses temperature of 38
o
C or
higher on BTEMP line for safety reasons.
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
Table 3: BSI resistor values
Parameter Min Typ Max Unit Notes
Battery size indicator resistor BSI 75 kΩ Battery size indicator (BLD-3)
Tolerance “1%
NTC thermistor BTEMP 47
4000
kΩ
K
Battery temperature indica-
tor (NTC pulldown) 47kΩ“5%
@ 25
o
C
Beta value (B).
Tolerance “5%, 25
o
C / 85
o
C
Char
ge
GND
2(BSI) 3(BTEMP) 4(GND)