Growatt SPA with GridZeno.

Growatt SPA on the compatibility list, updated 31 October 2026.

• Live overview of solar, consumption and gridAll subscriptions · Solar production from your other inverter isn't read.
  Works
• Battery state of chargeAll subscriptions · requires a battery
  Works
• Stop selling at negative pricesSmart and Pro · Requires the installer to have turned export limiting on in the inverter. GridZeno only lowers a limit that's already set.
  Works
• Charge from the grid when power is cheapSmart and Pro · requires a battery
  Works
• Discharge the battery when power is expensivePro · requires a battery
  Works

Works: tested and measured on real hardware.

An SPA is controlled with the inverter's own time windows.

Charge, hold and sell

Battery First for charging from the grid and holding, Grid First for selling from the battery.

Stop selling at negative prices

The inverter's export limit is set quarter by quarter by the selling price, but only where the installer has turned export limiting on. GridZeno only lowers a limit that's already set and never turns it on or off.

Back afterwards

The dongle saves the inverter's own settings before it changes them the first time, and puts them back when the plan is done and after a restart.

Manual

When the control is on Manual, the dongle changes nothing on the inverter. It reads, and if GridZeno has changed something, it puts the inverter's own settings back, including your own charge limits.

The type code 3725, SPA TL3. The dongle reads it with its own map: the SPH map without solar inputs and with nothing in the 2000 range.

The sun

The SPA has no solar inputs, so the dongle reads no solar production from it.

The battery

The capacity is worked out from the battery's full capacity from the BMS in input 1092 and the voltage in 1013.

What the dongle allows for

• The time windows are written as one block, after the opposite window is turned off, because the inverter refuses a window that overlaps an active one.
• Growatt's protocol marks windows 4-6 as used on the SPH. Whether an SPA has them isn't confirmed; if it answers with an exception, the dongle uses only window 1.

How it differs from SPH

SPA has no solar inputs. It charges a battery from the AC side of a solar system you already have, so the dongle reads no solar production from it.

SPH TL3 BH-UP has its own solar inputs. The type code is 3725 on SPA and 3601 on SPH, so the dongle tells them apart by itself.

The port, 485-1, and control with the inverter's own time windows are the same.

See the page about SPH

How it differs from its neighbours

• Growatt SPH: The SPH TL3 BH-UP has its own solar inputs and the type code 3601, but the same port and the same time windows.

For the installer: the registers

What the dongle uses over Modbus, if you want to follow along or troubleshoot. Don't change the registers yourself while control is set to Automatic.

Charging and hold

Battery First window 1 in 1100-1102 set to 00:00-23:59, the target in 1091, the power in 1090 and charging from the grid in 1092 (1 to charge, 0 to hold).

Sales

Grid First window 1 in 1080-1082, the floor in 1071 and the power in 1070.

Lowest charge level

608.

Export limit

123 in 0.1 %. 122 is the installer's switch and is never written.

From the dongle's firmware and our notes on each inverter, not from the datasheet.

Network cable with RJ45 plug. Approx. 20 minutes.

Port

485-1

Pin

A at pin 5 (RS485A), B at pin 1 (RS485B), GND at pin 2 (GND)

Where

In the port panel on the underside between USB and GRID, behind the waterproof cover, together with 485-2, 485-3, CAN, DRMS, METER and NTC. The cable is passed in through the cover's cable gland. 485-2 can be used instead if 485-1 is taken.

See the full installation guide for Growatt SPA

GridZeno Dongle for Growatt SPA

This one works.

Growatt SPA is the inverter GridZeno has been tested on. Check that your model is under SPA 4000-10000TL3 BH-UP, and that a battery is fitted if you want the battery controlled by the electricity price. If it still doesn't suit you, you have 100 days' free return.