SAX-Power Home Battery

Use cases

• Monitor state of charge and battery state on a live dashboard to track daily energy storage cycles.
• Set maximum charge and discharge power limits remotely to optimize self-consumption for residential PV systems.
• Create an alert when state of charge drops below a critical threshold to prevent deep discharge events.
• Log power meter values over time to analyze energy flows and validate battery performance for the end customer.
• Adjust the power factor (cosPhi) remotely to comply with local grid operator requirements.

Installation

1. 1Connect the ModbusCloud gateway (MCG or MLP series) to the same local network as the SAX-Power Home battery and verify IP connectivity.
2. 2Note the IP address of the SAX-Power Home battery and confirm that its Modbus TCP interface is active and reachable.
3. 3Import the SAX-Power Home Battery template in the ModbusCloud platform and assign the correct IP address of the battery in the Modbus TCP server configuration.
4. 4Subtract the offset of 16384 manually from the get_power and get_power_meter register values to obtain correct kilowatt readings.
5. 5Contact SAX-Power to request activation of write access for set_power, set_max_chargepower, set_max_dischargepower, and set_cosPhi before attempting to use control functions.
6. 6Verify all sensor readings on the ModbusCloud dashboard and confirm that values match the battery display before handing over to the customer.

Things to watch for

01

Why are my get_power and get_power_meter readings incorrect or very high?

The SAX-Power Home adds an offset of 16384 to these register values. You must subtract 16384 from the raw values manually to get the correct reading in kilowatts.

02

Why can I not write to the set_power or set_max_chargepower registers?

Write access to control registers (set_power, set_max_chargepower, set_max_dischargepower, set_cosPhi) is disabled by default. Contact SAX-Power directly to request activation of these functions.

03

What unit does the battery use for power values?

The battery sends and accepts power values in watts. The template converts these to kilowatts for display. Keep this in mind when interpreting raw register data.

04

What network setup is required for Modbus TCP communication?

The ModbusCloud gateway and the SAX-Power Home battery must be on the same local network. Ensure the battery IP address is static or reserved via DHCP, and that no firewall rules block Modbus TCP traffic on port 502.

Registers (8)

4 read / 5 write

More TCP templates

Domekt R 400 V

Komfovent

Modbus TCP

Controls Komfovent Domekt recuperator ventilation via Modbus TCP

25 registers118

Fronius - Modbus TCP

Fronius

Modbus TCP

Monitors Fronius Symo and Primo inverters via Modbus TCP

15 registers597

NIBE Nibe S-Series (SG Ready)

NIBE

Modbus TCP

5 registers1

SunSpec Model 709 — DER Trip LF

SunSpec

Modbus TCP

9 registers

Victron Meter AcOut

Victron

Modbus TCP

16 registers

FoxESS Avocado (grid)

FoxESS

Modbus TCP

8 registers