BQ78412 Datasheet, PDF (1/36 Pages) Texas Instruments – Pb-Acid Battery State-of-Charge Indicator With Run-Time Display

bq78412
www.ti.com
SLUSAA0 – OCTOBER 2010
bq78412 Pb-Acid Battery State-of-Charge Indicator With Run-Time Display
Check for Samples: bq78412
FEATURES
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• Designed for Use with 12-V Lead-Acid
Batteries in Consumer UPS Systems
• Programmable Cell Models for Enhanced
Pb-Acid Gas Gauging Performance
• Provides 10-LED Bar Graph of Run-Time
Remaining During Discharge and % Capacity
During Charge
• Can Be Easily Integrated Into Battery Cover
• Works with Pb-Acid Batteries Up to 327 Ah
• Records Cumulative Usage Data Internally for
Warranty Return Analysis
• On-Chip Temperature Sensor
• Data Interface for Retrieving Warranty
Information
• Fully Programmable Features and Thresholds
via UART Serial Interface
• State-of-Health (SoH) Determination and
Status Reporting
• Includes Configurable Signal for Audible
Low-Capacity, Low-Voltage, and Overvoltage
Warnings
• Addressable Commands for Use in
Multi-Battery Systems
• Optional Infra-Red Communications Interface
APPLICATIONS
• Stand-Alone Uninterruptible Power Supplies
• 12-V Pb-Acid Battery Monitors
• Battery Warranty Data Logging Equipment
DESCRIPTION
The bq78412 Pb-Acid Battery State-of-Charge (SoC)
Indicator with Run-Time Display is a complete
stand-alone battery gas-gauge solution designed for
single 12V Pb-Acid batteries. The bq78412 displays
remaining Run-Time-To-Empty during discharge and
Percent (%) capacity during charge using a 10-LED
(light-emitting diode) bar graph.
The bq78412 monitors battery voltage, current, and
ambient temperature to calculate state-of-charge and
determine remaining runtime-to-empty. Measured
values can be recorded and tracked for later retrieval
for warranty purposes.
Programmable cell models allow the bq78412 to be
customized to a variety of Pb-Acid formulations and
capacities.
Current measurements and Coulomb-counting for
gas-gauging are also automatically performed by the
bq78412. Current measurements use a small value
sense resistor placed in the negative power path and
calibrated in-circuit. This allows the precise,
continuous, real-time calculation of battery capacity
and run-time-to-empty values.
Temperature sensing augments gas-gauge and
capacity information using a firmware algorithm to
compensate for the temperature effects on capacity.
A serial port is available for configuring various
programmable parameters including cell models,
calibration values, serial number and date of
manufacture. The serial port can operate an infra-red
(IR) interface to allow connector-less data acquisition.
The bq78412 is easily configurable, is fully
programmed and requires no algorithm or firmware
development
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated