Product details


Charge current (Max) (A) 2 Operating Vin (Max) (V) 5.5 Cell chemistry Lead Acid Battery charge voltage (Min) (V) 0 Battery charge voltage (Max) (V) 20 Absolute Vin (safety rating) (Max) ((V)) 7 Control topology Switch-Mode Buck Control interface Standalone (RC-Settable) Operating Vin (Min) (V) 4.5 Rating Catalog open-in-new Find other Battery charger ICs

Package | Pins | Size

PDIP (N) 16 181 mm² 19.3 x 9.4 SOIC (D) 16 59 mm² 9.9 x 6 open-in-new Find other Battery charger ICs


  • Conforms to battery manufacturers' charge recommendations for cyclic and float charge
  • Pin-selectable charge algorithms

  • - Two-Step Voltage with temperature-compensated constant-voltage maintenance
    - Two-Step Current with constant-rate pulsed current maintenance
    - Pulsed Current: hysteretic, on-demand pulsed current
  • Pin-selectable charge termination by maximum voltage, 2V, minimum current, and maximum time
  • Pre-charge qualification detects shorted, opened, or damaged cells and conditions battery
  • Charging continuously qualified by temperature and voltage limits
  • Internal temperature-compensated voltage reference
  • Pulse-width modulation control

  • - Ideal for high-efficiency switch-mode power conversion
    - Configurable for linear or gated current use
  • Direct LED control outputs display charge status and fault conditions
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The bq2031 Lead-Acid Fast Charge IC is designed to optimize charging of lead-acid chemistry batteries. A flexible pulse-width modulation regulator allows the bq2031 to control constant-voltage, constant-current, or pulsed-current charging. The regulator frequency is set by an external capacitor for design flexibility. The switch-mode design keeps power dissipation to a minimum for high charge current applications.

A charge cycle begins when power is applied or the battery is replaced. For safety, charging is inhibited until the battery voltage is within configured limits. If the battery voltage is less than the low-voltage threshold, the bq2031 provides trickle-currentcharging until the voltage rises into the allowed range or an internal timer runs out and places the bq2031 in a Fault condition. This procedure prevents high-current charging of cells that are possibly damaged or reversed. Charging is inhibited anytime the temperature of the battery is outside the configurable, allowed range. All voltage thresholds are temperature-compensated.

The bq2031 terminates fast (bulk) charging based on the following:

  • Maximum voltage
  • Second difference of cell voltage (2V)
  • Minimum current (in constant-voltage charging)
  • Maximum time-out (MTO)
  • After bulk charging, the bq2031 provides temperature-compensated maintenance (float) charging to maintain battery capacity.

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    Technical documentation

    = Top documentation for this product selected by TI
    No results found. Please clear your search and try again. View all 9
    Type Title Date
    * Datasheet Lead-Acid Fast-Charge IC datasheet Sep. 05, 1999
    Technical articles When to use rechargeable batteries in small battery applications Oct. 01, 2019
    Application note Simple MPPT based Lead acid charger using BQ2031 (Rev. A) Aug. 08, 2017
    Technical articles Should I use a linear charger or a switching charger? Oct. 30, 2015
    Technical articles Summertime and the livin' is easy Jun. 20, 2014
    Application note 4Q 2011 Issue Analog Applications Journal Nov. 09, 2011
    Application note Solar charging solution provides narrow-voltage DC/DC system bus for multicell Nov. 09, 2011
    User guide DV2031S2 Lead-Acid Charger Development System Control of On-Board p-FET (Rev. B) Mar. 16, 2007
    Application note U-510 Using the bq2031 to Charge Lead-Acid Batteries Sep. 05, 1999

    Design & development

    For additional terms or required resources, click any title below to view the detail page where available.

    Software development

    Temp Sense Designer Software
    TEMPSENSE-SW The TempSense Designer software allows the user to easily design temperature sensing circuits for many of the Texas Instruments battery charger devices. A full listing of the supported devices is included under the "Support" menu in the program. The user can use the thermisters included in the (...)

    The program gives the user:

    • Worse-case limits of the resistance
    • Trip voltages
    • Temperatures of the design

    CAD/CAE symbols

    Package Pins Download
    PDIP (N) 16 View options
    SOIC (D) 16 View options

    Ordering & quality

    Information included:
    • RoHS
    • REACH
    • Device marking
    • Lead finish/Ball material
    • MSL rating/Peak reflow
    • MTBF/FIT estimates
    • Material content
    • Qualification summary
    • Ongoing reliability monitoring

    Support & training

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