From 362620ba07797f29204209a82df710f65a2a34f2 Mon Sep 17 00:00:00 2001
From: Michael Geers <michael@geers.tv>
Date: Sat, 18 Jul 2026 11:50:43 +0200
Subject: [PATCH] Battery (experimental): restore priority/buffer soc
 constraint (#31900)

---
 .../components/Battery/BatteryConfigCard.vue  | 24 +++++++++++++++----
 tests/battery-experimental.spec.ts            | 16 +++++++++++++
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/assets/js/components/Battery/BatteryConfigCard.vue b/assets/js/components/Battery/BatteryConfigCard.vue
index 89d973fc2..fa106b361 100644
--- a/assets/js/components/Battery/BatteryConfigCard.vue
+++ b/assets/js/components/Battery/BatteryConfigCard.vue
@@ -102,8 +102,7 @@ import InlineSocSelect from "./InlineSocSelect.vue";
 
 // Battery usage controls for the experimental page. The logic is intentionally duplicated
 // from the classic BatteryUsageSettings.vue (slated for removal) so the two can diverge
-// during the transition. Difference here: priority and buffer SoC are independent, there is
-// no priority < buffer constraint.
+// during the transition.
 export default defineComponent({
 	name: "BatteryConfigCard",
 	components: { Card, InlineSocSelect },
@@ -135,14 +134,21 @@ export default defineComponent({
 		priorityOptions() {
 			const options = [];
 			for (let i = 100; i >= 0; i -= 5) {
-				options.push({ value: i, name: this.fmtSoc(i) });
+				const disabled =
+					i > this.selectedBufferSoc &&
+					!(this.selectedBufferSoc == this.selectedPrioritySoc);
+				options.push({ value: i, name: this.fmtSoc(i), disabled });
 			}
 			return options;
 		},
 		bufferOptions() {
 			const options = [];
 			for (let i = 100; i >= 5; i -= 5) {
-				options.push({ value: i, name: this.fmtSoc(i) });
+				options.push({
+					value: i,
+					name: this.fmtSoc(i),
+					disabled: i < this.selectedPrioritySoc,
+				});
 			}
 			return options;
 		},
@@ -180,7 +186,15 @@ export default defineComponent({
 	},
 	methods: {
 		changePrioritySoc($event: Event) {
-			this.savePrioritySoc(parseInt(($event.target as HTMLInputElement).value, 10));
+			const soc = parseInt(($event.target as HTMLInputElement).value, 10);
+			if (soc > (this.bufferSoc || 100)) {
+				this.saveBufferSoc(soc);
+				if (soc > this.bufferStartSoc && this.bufferStartSoc > 0) {
+					this.setBufferStartSoc(soc);
+				}
+			} else {
+				this.savePrioritySoc(soc);
+			}
 		},
 		changeBufferStart($event: Event) {
 			this.setBufferStartSoc(parseInt(($event.target as HTMLInputElement).value, 10));
diff --git a/tests/battery-experimental.spec.ts b/tests/battery-experimental.spec.ts
index 9ebdc5807..774d391bd 100644
--- a/tests/battery-experimental.spec.ts
+++ b/tests/battery-experimental.spec.ts
@@ -73,6 +73,22 @@ test.describe("experimental battery page", async () => {
     await prioritySoc.selectOption("30");
     await expect(prioritySoc).toHaveValue("30");
 
+    // values crossing the other threshold are not selectable (prioritySoc 30, bufferSoc 80)
+    await expect(prioritySoc.getByRole("option", { name: "85%", exact: true })).toHaveAttribute(
+      "disabled",
+      ""
+    );
+    await expect(bufferSoc.getByRole("option", { name: "25%", exact: true })).toHaveAttribute(
+      "disabled",
+      ""
+    );
+
+    // equal values unlock higher priorities; selecting one raises the buffer instead
+    await prioritySoc.selectOption("80");
+    await prioritySoc.selectOption("85");
+    await expect(bufferSoc).toHaveValue("85");
+    await expect(prioritySoc).toHaveValue("80");
+
     // discharge control is offered for the controllable battery and toggles on
     const discharge = page.getByRole("switch", { name: /Prevent home battery/ });
     await expect(discharge).not.toBeChecked();