Huawei SUN2000 AC Charging: TOU Setup Issues

Experiencing problems with your Huawei SUN2000 inverter's AC charging, specifically when trying to switch to Time-of-Use (TOU) settings? You're not alone! Many users have run into a wall when attempting to automatically charge their batteries from the grid during off-peak hours. The core of the issue often lies in the inverter's workingModeSetting and how it interacts with the battery's standby mode. Let's dive into what's happening and how you might be able to resolve it.

Understanding the Problem: Battery Standby and TOU Settings

One of the primary challenges users face is the inverter's tendency to put the battery into standby mode overnight. When the battery is in standby, it's not actively running, which prevents certain control commands, like changing the workingModeSetting, from being applied. You might see an error message like: "inverter control: Event is discarded because battery is not running. State: inverter.0.battery.runningStatus = 4." This error clearly indicates that the system can't implement the requested change because the battery isn't active. Even if you try to change the setting via your ioBroker adapter (specifically inverter.0.control.battery.workingModeSettings), the inverter's web frontend might stubbornly display the old setting, like "maximalerEigenverbrauch" (maximum self-consumption), and refuse the update.

This behavior can be frustrating, especially when the goal is to leverage TOU electricity tariffs. Huawei's support has confirmed that to achieve automatic charging from the grid during specific times (TOU), the TOU setting must be active, and AC charging needs to be enabled. They also pointed out a crucial detail: the latest firmware (FW) on the dongle is essential. Older firmware versions have known issues with TOU functionality, which could be the root cause of these control problems. The question then becomes: is it safe to update to the latest firmware, such as V312, or will it freeze the system and make it inaccessible, as some users have experienced?

The Workaround: Manual TOU Activation

In the absence of a straightforward solution through the adapter, some users have found a temporary workaround: manually activating the TOU setting. When this is done, the battery often wakes up shortly after and begins charging as intended. While this gets the job done, it's far from ideal. It defeats the purpose of having an automated system if you have to manually intervene every time you want to utilize a specific charging mode. This manual activation suggests that the underlying issue isn't with the TOU logic itself, but rather with the automated command execution from the adapter when the battery is in a low-power state.

Exploring Solutions: Firmware Updates and Workarounds

Given the information from Huawei support, two main paths emerge for resolving this TOU configuration issue:

1. Trying the New Firmware (V312 or later): This is often the recommended first step. Huawei specifically mentioned that older firmware versions have problems with TOU. Updating to the latest stable firmware could resolve the bug that prevents the workingModeSetting from being applied correctly when the battery is in standby. However, there's a valid concern about the update process itself. Some users have reported that firmware updates can cause the inverter or dongle to become unresponsive, freezing the entire system. It's a gamble: the update might fix the TOU issue, or it might introduce new problems. If you decide to go this route, ensure you have a reliable method for firmware flashing and are prepared for potential complications. Researching user experiences with the specific V312 firmware on your model of SUN2000 inverter and dongle is highly recommended before proceeding.

2. Preventing Battery Standby: The alternative approach is to prevent the battery from entering standby mode in the first place. This is a less elegant solution but might be viable if firmware updates are too risky or unsuccessful. The idea is to periodically trigger a charging event, even a small one, to keep the battery active. This could involve setting up a very low-priority, short-duration charging schedule that runs intermittently throughout the night. The downside is that this might not be perfectly aligned with your TOU goals and could lead to unnecessary battery cycles or minor energy consumption just to keep the battery awake. It's a workaround that aims to bypass the