Solar Battery View

A Cinnamon panel applet that displays battery state of charge and power flow from a Fronius inverter via the Fronius Solar API v1.

Features

• Battery icon with color-coded SOC (green/yellow/red) and charge direction arrows (>> charging, << discharging)
• Solar panel icon showing grid status: green >> (exporting), red << (importing), blue = (neutral)
• SOC percentage displayed as text between the icons
• Tooltip with detailed power flow information (battery, PV, grid)
• Click to refresh data immediately
• Configurable thresholds for SOC colors, PV production, and grid export/import significance
• Charge alert: system notification and/or fullscreen dialog when the battery reaches a configured SOC while charging
• REST triggers: calls a configurable endpoint when the battery starts charging from surplus, and a second one when the battery runs low while discharging (e.g. to switch a smart plug)

Requirements

• A Fronius inverter (tested with Symo GEN24) accessible on the local network
• The Fronius Solar API v1 must be enabled (default on most models)
• A battery connected to the inverter (tested with BYD)

Configuration

• Inverter IP: IP address of your Fronius inverter
• Poll interval: How often to fetch data (5-300 seconds, click applet for manual refresh)
• SOC green threshold: SOC percentage at or above which the battery icon turns green
• SOC yellow threshold: SOC percentage at or above which the battery icon turns yellow (below is red)
• PV production threshold: PV power below this value is considered inactive (filters noise at night)
• Grid export/import threshold: Grid exchange below this value is shown as neutral (filters insignificant values)

Charge Alert

Alerts you once when the battery reaches a charge level. It only fires while the battery is charging, never while discharging.

• Alert when the battery reaches a charge level: master switch
• Alert at SOC: the level that triggers the alert (default 100%)
• Re-arm after SOC drops this far below the alert level: hysteresis, default 5%. A full battery stops charging and gets topped up again whenever the sun comes out. Without this band, every top-up would fire a new alert. With the default, the alert only re-arms once SOC drops below 95%.
• Alert type: notification only, fullscreen dialog only, or both. The notification is a critical one, so it stays in the message tray until dismissed. The dialog is a modal fullscreen overlay that has to be acknowledged with OK.

REST Triggers

Calls an HTTP endpoint when the battery changes between "charging from surplus" and "low and discharging". Intended for controlling a smart plug: switch a consumer on while there is surplus production, switch it off before the battery is drained.

• Endpoint 1 is called when the battery charges with at least Minimum charge power watts.
• Endpoint 2 is called when the battery discharges and SOC is below SOC below which discharging triggers endpoint 2.
• In between (neutral: idle battery, or discharging while still well charged) nothing is called - the plug keeps its last commanded state until the opposite condition is actually met.

Each endpoint takes a URL, a method (GET or POST), and an optional body plus content type for POST. The Test buttons fire the call immediately, so you can verify the configuration without waiting for the right weather. A test call does not change the remembered plug state.

Debouncing (solar power fluctuates heavily with passing clouds):

• Calls are edge triggered: an endpoint is called once on the state change, not on every poll.
• The condition must hold for Confirm condition for this many polls consecutive polls (default 3) before the call goes out.
• Charging only counts as surplus above Minimum charge power (default 100 W), which ignores trickle charging.
• The last successful action is persisted, so restarting Cinnamon does not re-fire it. A failed call is not persisted and is therefore retried on the next poll.

Example URLs:

Icon Legend

Battery Icon (right)

Solar Icon (left)