From 4cba60457ce1aa40ff9714c3e3e1a2e247caeb45 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmail.com>
Date: Sat, 26 Jul 2025 14:26:46 +0200
Subject: [PATCH] chore: fix slot length

---
 core/meterenergy.go  |  9 ++++-----
 core/site.go         |  2 +-
 core/site_tariffs.go |  5 +++++
 core/site_test.go    | 35 +++++++++++++++++++++++++++++++++++
 4 files changed, 45 insertions(+), 6 deletions(-)

diff --git a/core/meterenergy.go b/core/meterenergy.go
index d5316761e..ba4359e21 100644
--- a/core/meterenergy.go
+++ b/core/meterenergy.go
@@ -4,7 +4,6 @@ import (
 	"time"
 
 	"github.com/benbjohnson/clock"
-	"github.com/jinzhu/now"
 	"github.com/samber/lo"
 )
 
@@ -15,10 +14,12 @@ type meterEnergy struct {
 	Accumulated float64  `json:"accumulated"` // kWh
 }
 
+// AccumulatedEnergy returns the accumulated energy in kWh
 func (m *meterEnergy) AccumulatedEnergy() float64 {
 	return m.Accumulated
 }
 
+// AddMeterTotal adds the difference to the last total meter value in kWh
 func (m *meterEnergy) AddMeterTotal(v float64) {
 	defer func() {
 		m.updated = m.clock.Now()
@@ -32,6 +33,7 @@ func (m *meterEnergy) AddMeterTotal(v float64) {
 	m.Accumulated += v - *m.meter
 }
 
+// AddEnergy adds the given energy in kWh
 func (m *meterEnergy) AddEnergy(v float64) {
 	defer func() { m.updated = m.clock.Now() }()
 
@@ -42,10 +44,7 @@ func (m *meterEnergy) AddEnergy(v float64) {
 	m.Accumulated += v
 }
 
+// AddPower adds the given power in W, calculating the energy based on the time since the last update
 func (m *meterEnergy) AddPower(v float64) {
 	m.AddEnergy(v * m.clock.Since(m.updated).Hours() / 1e3)
 }
-
-func beginningOfDay(t time.Time) time.Time {
-	return now.With(t).BeginningOfDay()
-}
diff --git a/core/site.go b/core/site.go
index 8b56c69da..c8f718ff6 100644
--- a/core/site.go
+++ b/core/site.go
@@ -784,7 +784,7 @@ func (site *Site) updateHouseholdConsumption(totalChargePower float64) {
 		return
 	}
 
-	slotDuration := time.Minute
+	slotDuration := 15 * time.Minute
 	slotStart := now.Truncate(slotDuration)
 
 	if slotStart.After(site.householdSlotStart) {
diff --git a/core/site_tariffs.go b/core/site_tariffs.go
index a91289929..7b6387549 100644
--- a/core/site_tariffs.go
+++ b/core/site_tariffs.go
@@ -10,6 +10,7 @@ import (
 	"github.com/evcc-io/evcc/core/keys"
 	"github.com/evcc-io/evcc/server/db/settings"
 	"github.com/evcc-io/evcc/tariff"
+	"github.com/jinzhu/now"
 	"github.com/samber/lo"
 )
 
@@ -172,3 +173,7 @@ func (site *Site) isDynamicTariff(usage api.TariffUsage) bool {
 	tariff := site.GetTariff(usage)
 	return tariff != nil && tariff.Type() != api.TariffTypePriceStatic
 }
+
+func beginningOfDay(t time.Time) time.Time {
+	return now.With(t).BeginningOfDay()
+}
diff --git a/core/site_test.go b/core/site_test.go
index 9f176b8a1..83c325f1c 100644
--- a/core/site_test.go
+++ b/core/site_test.go
@@ -2,10 +2,16 @@ package core
 
 import (
 	"testing"
+	"time"
 
+	"github.com/benbjohnson/clock"
 	"github.com/evcc-io/evcc/api"
+	"github.com/evcc-io/evcc/core/metrics"
+	"github.com/evcc-io/evcc/server/db"
+	"github.com/evcc-io/evcc/util"
 	"github.com/evcc-io/evcc/util/config"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestGreenShare(t *testing.T) {
@@ -155,3 +161,32 @@ func TestRequiredBatteryMode(t *testing.T) {
 		assert.Equal(t, tc.res, res, "expected %s, got %s", tc.res, res)
 	}
 }
+
+func TestUpdateHouseholdConsumption(t *testing.T) {
+	clock := clock.NewMock()
+
+	require.NoError(t, db.NewInstance("sqlite", ":memory:"))
+	metrics.Init()
+
+	s := &Site{
+		log:             util.NewLogger("foo"),
+		gridPower:       4e3,
+		householdEnergy: &meterEnergy{clock: clock},
+	}
+
+	clock.Add(5 * time.Minute)
+	s.updateHouseholdConsumption(1e3)
+	require.False(t, s.householdEnergy.updated.IsZero())
+
+	clock.Add(5 * time.Minute)
+	s.updateHouseholdConsumption(1e3)
+	require.Equal(t, 0.25, s.householdEnergy.AccumulatedEnergy())
+
+	clock.Add(5 * time.Minute)
+	s.updateHouseholdConsumption(1e3)
+	require.Equal(t, 0.0, s.householdEnergy.AccumulatedEnergy()) // accumulator reset after 15 minutes
+
+	clock.Add(15 * time.Minute)
+	s.updateHouseholdConsumption(1e3)
+	require.Equal(t, 0.0, s.householdEnergy.AccumulatedEnergy()) // accumulator reset after 15 minutes
+}