BYD Battery Box Visualization for Home Assistant (Lovelace Card)

BYD HVS & BYD HVM Visualization for HACS byd_battery_box (Home Assistant)

Visualize BYD Battery Box modules and cells with current, min/max voltages and temperatures in Home Assistant.

Installation (HACS)

1. In Home Assistant → HACS → Frontend → Three-dots → Custom repositories → Add:
   • Repository: TimWeyand/byd_battery_box_visualization
   • Category: Frontend
2. Install "BYD Battery Box Visualization" from HACS.
3. Add the resource (Settings → Dashboards → Resources):
   • URL: /hacsfiles/byd_battery_box_visualization/byd-battery-box-visualization.js (type: module)

Add the card (GUI)

Use the Lovelace UI to add the card custom:byd-battery-box-visualization. A built-in editor is provided (no YAML needed) to set chart ranges, unit, Y-axis visibility, and whether to show gray caps beyond each cell's historic min/max.

Example (YAML)

• type: custom:byd-battery-box-visualization voltage_min: 3100 voltage_max: 3500 temp_min: 10 temp_max: 45 show_y_axis: true # set to false to hide the Y-axis guide and labels show_gray_caps: true # set to false to disable gray caps beyond per-cell historic min/max

Notes:

• The card auto-discovers entities from the byd_battery_box integration. There is 1 BMU and up to 3 BMS (towers).
• Each tower renders a header (SOC bar with charge/discharge animation), modules (2–10) and a stand.
• Header shows per‑tower capacity (from sensor.total_capacity divided by number of towers) and, when not idle, an ETA to full/empty using a 5‑minute moving average of BMU power.
• Voltage view: per-cell bars showing current (green), optional dark gray caps to indicate chart range beyond each cell's historic min/max (disable via show_gray_caps). Balancing cells turn blue.
• Temperature view: shows per-sensor bars; balancing does not change bar color. Toggle between mV/°C in the header.
• Hover or click on any bar to show its value as a tooltip.
• All custom elements are updated incrementally without full DOM re-creation to minimize flicker.
• All custom components are fully responsive and can be tested without Home Assistant (see below).

Test page / Development

Open test/index.html in a browser to see the standalone demo filled with mock data (no Home Assistant required).

Controls on the test page:

• Show Y-axis checkbox: toggles axis labels and full-width guide lines on modules.
• Randomize button: regenerates SOC, SOH, per-cell voltages, historic min/max, balancing, temperatures, and BMU power.

Included mock data (test/mock-data.js):

• 3 towers, each with 5 modules by default
• Per-cell voltages (32 per module), historic min/max derived from the current values
• Per-cell balancing flags
• Per-sensor temperatures (half the number of cells)
• BMU power and versions
• Simulated total capacity (12.8 kWh) with per‑tower capacity display and ETA to full/empty shown in the header