XW PRO Li-ion Battery Solution Guide

Overview
The XW Pro is a utility interactive inverter/charger with grid-tied, off-grid, and backup power
capability. The XW Pro inverters communicate with third party devices, such as a Li-ion
Battery Management System (BMS), through the Conext Gateway, InsightHome, or
InsightFacility. These devices provide a CAN Bus or Modbus RTU interface for BMS
communication. The BMS communication can only work with compatible batteries listed in
this document.
Li-ion batteries must have an on-board BMS, that, in addition to providing functions of
protection, cell balancing, state-of-charge (SOC) and state-of-health (SOH) calculation, also
provide a reference for charging voltage and charging current. This reference may be
optimized dynamically by the BMS, taking into account the battery SOC, SOH,
temperature, or other factors. It is necessary, in such cases, to update the charging
characteristics of the XW Pro dynamically as these values change. The operation described
in this application note applies to all BMS communication protocols that the system is
compatible with.
Supported Architectures
The following diagrams provide a typical system architecture of the Conext Gateway, XW
Pro, and a Li-ion battery with BMS. Currently BMS communication is supported for systems
with a single XW Pro inverter and optional AC coupled PV inverters. Systems with multiple
XW Pro inverters and DC coupled systems with Conext MPPT solar charge controller not
currently available with BMS communication (future release). Systems with multiple XW
Pro inverters and/or DC coupling with Conext MPPT solar charge controller may be
installed without BMS communications subject to the battery vendor approval of the use-
case. A Conext Battery Monitor is recommended for these applications to monitor the
battery SOC.
Single XW Pro with Single Master BMS (Split-Phase and Single-Phase) with AC Coupling
The XW Pro with compatible Li-ion batteries can be used with AC coupled PV inverters or
microinverters. The XW Pro will regulate charging from the AC coupled PV inverters using
frequency shifting, based on the battery charging limits and SOC information communicated
by the BMS. See the XW Pro AC Coupling Solutions Guide (document part number: 990-
6421) for information on the design and installation of AC coupled systems, and be sure to
follow all system sizing and other application requirements as described in the document.
990-6359A This manual is intended for use by qualified personnel 3
XW Pro Li-ion Battery Solution Guide