The bq78PL114 master gateway battery controller is part of a complete Li-Ion control, monitoring, and safety solution designed for large series cell strings.
The bq78PL114 and bq78PL114S12 along with bq76PL102 PowerLAN™ dual-cell monitors provide complete battery-system control, communications, and safety functions for a structure of three up to twelve series cells. This PowerLAN system provides simultaneous, synchronized voltage and current measurements using one A/D per-cell technology. This eliminates system-induced noise from measurements and allows the precise, continuous, real-time calculation of cell impedance under all operating conditions, even during widely fluctuating load conditions.
PowerPump technology transfers charge between cells to balance their voltage and capacity. Balancing is possible during all battery modes: charge, discharge, and rest. Highly efficient charge-transfer circuitry nearly eliminates energy loss while providing true real-time balance between cells, resulting in longer run-time and improved cycle life.
Temperature is sensed by up to 12 external sensors and one on-chip sensor. This permits accurate temperature monitoring of each cell individually. Firmware is then able to compensate for the temperature-induced effects on capacity, impedance, and OCV on a cell-by-cell basis, resulting in superior charge/ discharge and balancing control.
External MOSFET control inputs provide user- definable direct hardware control over MOSFET states. Smart control prevents excessive current through MOSFET body diodes. Auxiliary inputs can be used for enhanced safety and control in large multicell arrays.
The bq78PL114 is completely user-configurable, with parametric tables in flash memory to suit a variety of cell chemistries, operating conditions, safety controls, and data reporting needs. It is easily configured using the supplied bqWizard graphical user interface (GUI). The device is fully programmed and requires no algorithm or firmware development.
The bq78PL114 can be upgraded to the bq78PL114S12 by downloading the bq78PL114S12 firmware. The firmware can be downloaded using the bqWizard application or during manufacturing. Upgrading to the bq78Pl114S12 changes the functionality of the LED1-LED5, LEDEN, and N/C pin #29. The bq78PL114S12 pin functions of LED1/SEG1-LED5/SEG5, PSH/BP/TP, and FIELD support LED, LCD, and electronic paper displays (EPDs). The user can configure the bq78PL114S12 for the desired display type.
In this document all descriptions for the bq78PL114 apply to the bq78PL114S12 except where different bq78PL114S12 functionality is specifically described.