From 4360914d75f0beec5951d458cb4f8803b332aebf Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Thu, 16 Nov 2023 16:55:43 +0100
Subject: [PATCH 1/5] Add chargeable battery charger

---
 charger/battery.go | 96 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 charger/battery.go

diff --git a/charger/battery.go b/charger/battery.go
new file mode 100644
index 0000000000..6f0797c40b
--- /dev/null
+++ b/charger/battery.go
@@ -0,0 +1,96 @@
+package charger
+
+import (
+	"fmt"
+
+	"github.com/evcc-io/evcc/api"
+	"github.com/evcc-io/evcc/util"
+	"github.com/evcc-io/evcc/util/config"
+)
+
+type ChargeableBattery interface {
+	api.Meter
+	api.Battery
+	api.BatteryController
+}
+
+// Battery implements an api.Charger for controllable batteries
+type Battery struct {
+	*embed
+	ChargeableBattery
+	mode api.BatteryMode
+}
+
+func init() {
+	registry.Add("battery", NewBatteryFromConfig)
+}
+
+func NewBatteryFromConfig(other map[string]interface{}) (api.Charger, error) {
+	cc := struct {
+		embed   `mapstructure:",squash"`
+		Battery string
+	}{
+		embed: embed{
+			Icon_:     "battery",
+			Features_: []api.Feature{api.IntegratedDevice},
+		},
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	dev, err := config.Meters().ByName(cc.Battery)
+	if err != nil {
+		return nil, err
+	}
+
+	battery, ok := dev.Instance().(ChargeableBattery)
+	if !ok {
+		return nil, fmt.Errorf("'%s' is not a chargeable battery", cc.Battery)
+	}
+
+	c := &Battery{
+		ChargeableBattery: battery,
+	}
+
+	return c, nil
+}
+
+// Status calculates the battery charging status
+func (c *Battery) Status() (api.ChargeStatus, error) {
+	res := api.StatusB
+
+	p, err := c.ChargeableBattery.CurrentPower()
+	if p > 0 && err == nil {
+		res = api.StatusC
+	}
+
+	return res, err
+}
+
+// Enabled implements the api.Charger interface
+func (c *Battery) Enabled() (bool, error) {
+	return c.mode == api.BatteryCharge, nil
+}
+
+// Enable implements the api.Charger interface
+func (c *Battery) Enable(enable bool) error {
+	mode := api.BatteryNormal
+	if enable {
+		mode = api.BatteryCharge
+	}
+
+	// TODO handle locking of battery
+	err := c.ChargeableBattery.SetBatteryMode(mode)
+	if err == nil {
+		c.mode = mode
+	}
+
+	return err
+}
+
+// MaxCurrent implements the api.Charger interface
+func (c *Battery) MaxCurrent(current int64) error {
+	return nil
+}

From 8fc252fec72352b21d0d8358f8793224a7a363d8 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Thu, 21 Mar 2024 19:40:36 +0100
Subject: [PATCH 2/5] wip

---
 charger/battery.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/charger/battery.go b/charger/battery.go
index 6f0797c40b..471c336d9b 100644
--- a/charger/battery.go
+++ b/charger/battery.go
@@ -51,6 +51,7 @@ func NewBatteryFromConfig(other map[string]interface{}) (api.Charger, error) {
 	}
 
 	c := &Battery{
+		embed:             &cc.embed,
 		ChargeableBattery: battery,
 	}
 

From 76c738130590f6ebc73dbec7399481fe482e228d Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Sat, 23 Mar 2024 09:55:33 +0100
Subject: [PATCH 3/5] Flip power sign

---
 charger/battery.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/charger/battery.go b/charger/battery.go
index 471c336d9b..047493789c 100644
--- a/charger/battery.go
+++ b/charger/battery.go
@@ -95,3 +95,11 @@ func (c *Battery) Enable(enable bool) error {
 func (c *Battery) MaxCurrent(current int64) error {
 	return nil
 }
+
+var _ api.Meter = (*Battery)(nil)
+
+// CurrentPower implements the api.Meter interface
+func (c *Battery) CurrentPower() (float64, error) {
+	res, err := c.ChargeableBattery.CurrentPower()
+	return -res, err
+}

From 642b666841ffd8f6909b08ec5c0a465eb1dc1241 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Sat, 23 Mar 2024 09:59:34 +0100
Subject: [PATCH 4/5] Cap power at 0

---
 charger/battery.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/charger/battery.go b/charger/battery.go
index 047493789c..40d87ae504 100644
--- a/charger/battery.go
+++ b/charger/battery.go
@@ -101,5 +101,5 @@ var _ api.Meter = (*Battery)(nil)
 // CurrentPower implements the api.Meter interface
 func (c *Battery) CurrentPower() (float64, error) {
 	res, err := c.ChargeableBattery.CurrentPower()
-	return -res, err
+	return max(-res, 0), err
 }

From 298ea702efb50e3dd10cebd97f5cce34f633c258 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Fri, 29 Mar 2024 21:47:05 +0100
Subject: [PATCH 5/5] Fix disabled but charging

---
 charger/battery.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/charger/battery.go b/charger/battery.go
index 40d87ae504..66e42d841e 100644
--- a/charger/battery.go
+++ b/charger/battery.go
@@ -100,6 +100,10 @@ var _ api.Meter = (*Battery)(nil)
 
 // CurrentPower implements the api.Meter interface
 func (c *Battery) CurrentPower() (float64, error) {
+	if c.mode != api.BatteryCharge {
+		// disabled
+		return 0, nil
+	}
 	res, err := c.ChargeableBattery.CurrentPower()
 	return max(-res, 0), err
 }