1 Features

1• Fuel gauge and battery diagnostics for flow meter

applications predict end-of-service or early battery

failure

– Supports lithium thionyl chloride (Li-SOCl2)

and lithium manganese dioxide (Li-MnO2)

chemistry batteries

– Accurate voltage, temperature, current, and

coulomb counter measurements that report

battery health and service life

– State-of-health (SOH) algorithm for Li-MnO2

– End-of-service (EOS algorithm for Li-SOCl2)

– Coulomb accumulation (ACC) algorithm for all

battery types

• Ultra-low average power consumption to

maximize battery run time

– Gauge enabled through host-controlled

periodic updates

– State-of-health (SOH) ~0.06 μA

– End-of-service (EOS) ~0.35 μA

– Coulomb accumulation (ACC) diagnostic

updates ~0.3 μA

• System interaction capabilities

– I2C host communication, providing battery

parameter and status access

– Configurable host interrupt

– Battery information data logging options for in

operation diagnostics and failure analysis

– SHA-1 authentication to help prevent

counterfeit battery use

2 Applications

• Used in primary battery systems and suitable for

dynamic load and large ambient temperature

change applications

– Smart meters and flow meters

– Door access control

– Smoke and gas leak detectors

– Building automation

– IoT, including sensor nodes

– Asset tracking

• Battery status reporting and diagnostics with early

failure detection for flow meter systems

• Extends battery runtime with accurate battery

gauging for smoke detector, sensor node, and

asset tracker applications

3 Description

The BQ35100 Battery Fuel Gauge and End-Of-

Service Monitor provides highly configurable fuel

gauging for non-rechargeable (primary) lithium

batteries without requiring a forced discharge of the

battery. Built so that optimization is not necessary to

achieve accurate gauging, the BQ35100 device uses

patented TI gauging algorithms to support the option

to seamlessly replace an old battery with a new one.

The BQ35100 device provides accurate results with

ultra-low average power consumption where less

than 2 μA can be achieved through host control via

the GAUGE ENABLE (GE) pin. The device is only

required to be powered long enough, at a systemdetermined

update frequency, to gather data and to

make calculations to support the selected algorithm.

A typical system may need to only be updated once

every 8 hours as the gauge is not required to be

powered to measure all discharge activity.

The fuel gauging functions use voltage, current, and

temperature measurements to provide state-of-health

(SOH) data and end-of-service (EOS) warning

information where the host can read the gathered

data through a 400-kHz I2C bus. An ALERT output,

based on a variety of configurable status and data

options, is also available to interrupt the host.