Features
➤ Accurate measurement of available
charge in rechargeable batteries
➤ Designed for electric assist bicycles
and other applications
➤ Measures a wide dynamic current
range
➤ Supports NiCd,NiMH or lead acid
➤ Designed for battery pack integration
- 120μA typical standby current
(self-discharge estimation mode)
- Small size enables implementations
in as little as 1
2 square inch of PCB
➤ Direct drive of LEDs for capacity
display
➤ Automatic charge and selfdischarge
compensation using internal
temperature sensor
➤ Simple single-wire serial communications
port for subassembly
testing
➤ 16-pin narrow SOIC

General Description
The bq2013H Gas Gauge IC is intended
for battery-pack installation to
maintain an accurate record of a battery’s
available charge. The IC monitors
a voltage drop across a sense resistor
connected in series between the
negative battery terminal and ground
to determine charge and discharge activity
of the battery. The bq2013H is
designed for high cpaacity battery
packs used in high-discharge rate systems.
Battery self-discharge is estimated
based on an internal timer and temperature
sensor. Compensations for
battery temperature, rate of charge,
and self-discharge are applied to the
charge counter to provide available
capacity information across a wide
range of operating conditions. Initial
battery capacity, self-discharge rate,
display mode, and charge compensation
are set using the PROG1-6 pins.
Actual battery capacity is automatically
“learned” in the course of a discharge
cycle from full to empty.
Nominal available charge may be
directly indicated using a five-segment
LED display. These segments
are used to graphically indicate
nominal available charge.
The bq2013H supports a simple
single-line bi-directional serial link to
an external processor (common
ground). The bq2013H outputs battery
information in response to external
commands over the serial link. To
support battery pack testing, the
outputs may also be controlled by
command. The external processor
may also overwrite some of the
bq2013H gas gauge data registers.
The bq2013H may operate directly
from four nickel cells or three lead
acid. With the REF output and an
external transistor, a simple, inexpensive
regulator can be built to provide
VCC from a greater number of cells.
Internal registers include available
charge, temperature, capacity, battery
ID, and battery status.