Modern battery systems do not operate in isolation. Whether you are managing a residential solar installation, a commercial energy storage rack, or an industrial EV fleet, your BMS needs to communicate — with inverters, monitoring platforms, building management systems, and remote dashboards.

This guide covers how DALY Smart BMS connects to IoT infrastructure as an RS485 BMS, CAN bus BMS, and Bluetooth-enabled device, and how to integrate BMS data into SCADA and energy management platforms via standard RS485 BMS communication protocols.

Why Communication Protocol Matters for B2B BMS Buyers

A BMS that only protects cells is a 2010-era solution. Today’s B2B buyers require BMS units that can:

• Report real-time SOC, SOH, cell voltages, and temperature to a central monitoring system
• Accept remote commands: charge enable, discharge enable, wake/sleep
• Log historical data for preventive maintenance and warranty management
• Interface with third-party inverters, chargers, and energy management systems
• Support multi-pack parallel communication in large battery string configurations

The protocol your BMS supports determines which capabilities are available and which third-party systems it is compatible with.

DALY Smart BMS Communication ProtocolsRS485 — MODBUS RTU

RS485 is the dominant industrial communication standard for RS485 BMS-to-SCADA integration. It uses a two-wire differential signal supporting cable runs up to 1,200 meters and multi-device networks with up to 32 nodes per segment. An RS485 BMS can communicate with SCADA platforms, inverters, and energy management systems using the MODBUS RTU protocol.

RS485 Parameter	DALY Smart BMS Specification
Protocol	MODBUS RTU
Baud rate	9600 bps default; configurable to 115200 bps
Data frame	8N1 (8 data bits, no parity, 1 stop bit)
Readable data	Per-cell voltage, pack voltage, current, SOC, SOH, temperature (4× NTC), protection flags, cycle count
Writable commands	Charge enable/disable, discharge enable/disable, balance on/off, SOC calibration
Compatible systems	Growatt, Deye/Sunsynk, Modbus-capable SCADA (Ignition, Wonderware, WinCC, Home Assistant)

Full register documentation is available for download at /daly-product-manual/

CAN Bus — SAE J1939 / Custom Frame

CAN bus is the standard for automotive and heavy industrial applications. It offers faster communication speeds than RS485, deterministic timing, and built-in error detection — preferred for EV BMS, commercial vehicle battery systems, and grid-scale energy storage.

CAN Parameter	DALY Smart BMS Specification
Standard	CAN 2.0B
Speed	250 kbps / 500 kbps selectable
Frame format	Extended ID (29-bit)
Protocol variants	Custom DALY frame (documented); SAE J1939 compatible on request
Applications	EV charging stations, commercial vehicle BMS, industrial battery strings, telecom backup

Bluetooth — BLE 4.0/5.0 + Mobile App

For installations where wired communication is impractical — residential storage, RV systems, portable packs — DALY Smart BMS includes BLE connectivity with a free iOS/Android application.

• Real-time display: cell voltages per cell, pack voltage, current, SOC, SOH estimate
• Temperature monitoring: up to 4 sensor points
• Protection log: timestamped history of all triggered protection events
• Parameter configuration: adjust voltage and current thresholds within factory-defined safe limits
• OTA firmware update: supported on applicable models

UART — Direct Serial

Used for direct microcontroller integration in custom OEM designs where the BMS communicates with an embedded controller. Full UART protocol documentation available for OEM customers under NDA.

Connecting DALY Smart BMS to SCADA Platforms

Standard Integration Path: RS485 → MODBUS RTU

The most common integration path for commercial and industrial installations:

Layer	Component	Notes
BMS	DALY Smart BMS	RS485 port standard on all models
Field bus	RS485 two-wire cable	Up to 1,200m; 120Ω termination at each end
Gateway	RS485-to-TCP/IP converter	e.g., Moxa MB3170, Advantech Adam-4570
Platform	SCADA / EMS software	Any MODBUS TCP-capable system
Output	Dashboard / alerts / data log	SOC, cell health, protection events

Inverter Integration

For solar energy storage, the BMS communicates with the inverter to coordinate charge and discharge behavior. The BMS reports SOC and voltage limits; the inverter adjusts charge current accordingly.

• Growatt (RS485 MODBUS) — tested compatible with DALY RS485 MODBUS implementation; register map at /daly-product-manual/
• Deye / Sunsynk (RS485) — tested compatible with DALY RS485 MODBUS implementation; register map at /daly-product-manual/
• Victron Energy — via protocol converter (Victron GX device with custom driver)
• SMA, Fronius — custom CAN integration available on request → See also: DALY Communication Protocols Explained: /news/daly-three-communication-protocols-explanation/ → BMS-to-Inverter Wiring Guide: /news/how-to-wire-daly-bms-to-the-inverter/

Multi-Pack Parallel Communication

Large battery systems use multiple BMS units in a master-slave configuration. DALY supports RS485 daisy-chain topology with addressable device IDs (1–247). One master BMS aggregates data from all slave units. SCADA reads the master BMS for system-level data.

Maximum string configuration: up to 16 BMS units per RS485 segment before requiring a repeater.

Specification Summary for Integration Planning

Parameter	What to Verify	DALY Smart BMS
Protocol	RS485 / CAN / BLE — which does your system require?	All three standard
Baud rate	Must match gateway or inverter setting	Configurable
Register documentation	Full MODBUS map available for integrator?	Yes — downloadable
Update rate	How often does BMS transmit data?	100 ms–1 s configurable
Multi-pack topology	Master-slave support for large strings?	Yes, up to 16 units
OEM customization	Protocol customizable for OEM integration?	Yes — NDA required
Certifications	CE, UN38.3 for export compliance?	CE + UN38.3 standard

Product Configurations

DALY Smart BMS is available in the following series configurations:

Cell series: 4S / 7S / 8S / 10S / 12S / 13S / 14S / 15S / 16S / 17S / 20S / 24S

Current ratings: 40A / 60A / 80A / 100A / 150A / 200A / 250A / 300A

Chemistry: LiFePO4 (3.2V/cell) · NMC (3.7V/cell) · NCA · LTO (2.4V/cell)

All units include RS485 and Bluetooth as standard. CAN bus and UART available on selected models or as OEM option.

Frequently Asked QuestionsDoes DALY BMS support MODBUS TCP directly?

DALY Smart BMS natively supports MODBUS RTU over RS485. For MODBUS TCP, use a standard RS485-to-TCP gateway — a common, low-cost component available from Moxa, Advantech, and similar suppliers.

Can BMS parameters be configured remotely via RS485?

Yes. Writeable registers allow remote adjustment of voltage thresholds, current limits, and balance settings. The full write register list is available in the protocol documentation.

What is the maximum RS485 cable length?

Up to 1,200 meters with 120Ω termination resistors at each end of the bus. Use a signal repeater for longer runs.

Is protocol documentation available for third-party integrators?

RS485 MODBUS register maps are publicly available on the download page. CAN bus frame documentation and UART protocol specifications are available for OEM customers under NDA.

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