User Guide

Table Of Contents

Energy management

Battery interface

The phone is powered by a 3-pole BL-5C S-pack 1020 mAh battery. The three poles are named VBAT, BSI and

GND where the BSI line is used to recognize the battery capacity. This is done by means of an internal battery

pull down resistor.

Figure 15 Battery pin order

The battery temperature is estimated by measuring separate battery temperature NTC via the BTEMP line.

This is located on the main PWB, at the place where the phone temperature is closest to the battery

temperature.

Battery connector

The battery connector is a 3-pole connector.

• BSI (Battery size indicator)

• GND (Ground)

• VBAT (Battery voltage)

The BSI line is used to recognize the battery capacity by a battery internal pull down resistor.

Charging

This phone is charged through the smaller Nokia standard interface (2.0 mm plug). The wider standard

charger (3.5 mm) can be used together with the CA-44 charger adapter.

Figure 16 Small (left) and wide (right) charger plugs

Charging is controlled by energy management, and external components are needed to protect the baseband

module against EMC, reverse polarity and transient frequency deviation.

RM-429

System Module

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