18-Cell Battery Monitor with Daisy Chain Interface

The ADBMS18181 is a multicell battery stack monitor that measures up to 18 series connected battery cells with a total measurement error of less than 3.0 mV. The cell measurement range of 0 V to 5 V makes the ADBMS1818 suitable for most battery chemistries. All 18 cells can be measured in 290 μs, and lower data acquisition rates can be selected for high noise reduction.

Multiple ADBMS1818 devices can be connected in series, permitting simultaneous cell monitoring of long, high voltage battery strings. Each ADBMS1818 has an isoSPI™ interface for high speed, RF immune, long distance communications. Multiple devices are connected in a daisy chain with one host processor connection for all devices. This daisy chain can be operated bidirectionally, ensuring communication integrity, even in the event of a fault along the communication path.

The ADBMS1818 can be powered directly from the battery stack or from an isolated supply. The ADBMS1818 includes passive balancing for each cell, with individual PWM duty cycle control for each cell. Other features include an on-board 5 V regulator, nine general purpose I/O lines, and a sleep mode, where current consumption is reduced to 6 μA.

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1 Protected by multiple U.S. patents, including 8908779, 9182428, and 9270133.

APPLICATIONS

* Backup battery systems

* Grid energy storage

* Residential energy storage

* UPS

* High power portable equipment

* Measures up to 18 battery cells in series

* 3 mV maximum total measurement error

* Stackable architecture for high voltage systems

* Built-in isoSPI interface

* 1 Mb isolated serial communications

* Uses a single twisted pair, up to 100 meters

* Low EMI susceptibility and emissions

* Bidirectional for broken wire protection

* 290 μs to measure all cells in a system

* Synchronized voltage and current measurement