diff --git a/src/main/java/object/jaydenrandrews/Phone.java b/src/main/java/object/jaydenrandrews/Phone.java
new file mode 100644
index 0000000..95d85ca
--- /dev/null
+++ b/src/main/java/object/jaydenrandrews/Phone.java
@@ -0,0 +1,74 @@
+package object.jaydenrandrews;
+
+public class Phone {
+    private String brand;
+    private String model;
+    private int storageGB;
+    private boolean isOn;
+    private int batteryLife;
+
+    public Phone(String brand, String model, int storageGB, int batteryLife) {
+        if (storageGB <= 0) {
+            throw new IllegalArgumentException("Storage must be positive");
+        }
+        if (batteryLife < 0 || batteryLife > 100) {
+            throw new IllegalArgumentException("Battery must be between 0 and 100");
+        }
+
+        this.brand = brand;
+        this.model = model;
+        this.storageGB = storageGB;
+        this.isOn = false;
+        this.batteryLife = batteryLife;
+    }
+
+    public String getBrand() {
+        return brand;
+    }
+
+    public void setBrand(String brand) {
+        this.brand = brand;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public void setModel(String model) {
+        this.model = model;
+    }
+
+    public boolean isOn() {
+        return isOn;
+    }
+
+    public void powerOn() {
+        this.isOn = true;
+    }
+
+    public void powerOff() {
+        this.isOn = false;
+    }
+
+    public int getStorageGB() {
+        return storageGB;
+    }
+
+    public void setStorageGB(int storageGB) {
+        this.storageGB = storageGB;
+    }
+
+    public void charge(int amount) {
+        int newCharge = amount + this.getBatteryLife();
+        this.batteryLife = Math.min(newCharge, 100);
+    }
+
+    public void useBattery(int amount) {
+        int newCharge = this.getBatteryLife() - amount;
+        this.batteryLife = Math.max(0, newCharge);
+    }
+
+    public int getBatteryLife() {
+        return batteryLife;
+    }
+}
diff --git a/src/test/java/object/jaydenandrews/PhoneTest.java b/src/test/java/object/jaydenandrews/PhoneTest.java
new file mode 100644
index 0000000..6f530cf
--- /dev/null
+++ b/src/test/java/object/jaydenandrews/PhoneTest.java
@@ -0,0 +1,148 @@
+package object.jaydenandrews;
+
+import object.jaydenrandrews.Phone;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class PhoneTest {
+    @Test
+    public void constructor_HappyPath_ShouldInitializeFieldsCorrectly() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = 128;
+        int batteryLife = 75;
+
+        // Act
+        Phone phone = new Phone(brand, model, storageGB, batteryLife);
+
+        // Assert
+        assertEquals(brand, phone.getBrand());
+        assertEquals(model, phone.getModel());
+        assertEquals(storageGB, phone.getStorageGB());
+        assertEquals(batteryLife, phone.getBatteryLife());
+    }
+
+    @Test
+    public void assertInvalidStorage() {
+        // Act & Assert
+        assertThrows(IllegalArgumentException.class, () -> { new Phone("Samsung", "Galaxy S21", -1, 100);
+        });
+    }
+
+    @Test
+    public void assertInvalidBatteryLifeLessThan() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = -1;
+        int batteryLife = 75;
+        boolean isOn = false;
+
+        // Act & Assert
+        assertThrows(IllegalArgumentException.class, () -> { new Phone("Samsung", "Galaxy S21", 128, -1);
+        });
+    }
+
+    @Test
+    public void assertInvalidBatteryGreaterThan() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = -1;
+        int batteryLife = 75;
+        boolean isOn = false;
+
+        // Act & Assert
+        assertThrows(IllegalArgumentException.class, () -> { new Phone("Samsung", "Galaxy S21", 128, 101);
+        });
+    }
+
+    @Test
+    public void assertSettersWorkCorrectly() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = 128;
+        int batteryLife = 75;
+
+        // Act
+        Phone phone = new Phone(brand, model, storageGB, batteryLife);
+        phone.setBrand("Samsung");
+        phone.setStorageGB(256);
+        phone.setModel("Galaxy S20");
+
+        // Assert
+        assertEquals("Samsung", phone.getBrand());
+        assertEquals("Galaxy S20", phone.getModel());
+        assertEquals(256, phone.getStorageGB());
+    }
+
+    @Test
+    public void assertPowerOnWorksCorrectly() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = 128;
+        int batteryLife = 75;
+
+        // Act
+        Phone phone = new Phone(brand, model, storageGB, batteryLife);
+        phone.powerOn();
+
+        // Assert
+        assertTrue(phone.isOn());
+    }
+
+    @Test
+    public void assertPowerOffWorksCorrectly() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = 128;
+        int batteryLife = 75;
+
+        // Act
+        Phone phone = new Phone(brand, model, storageGB, batteryLife);
+        phone.powerOn();
+        phone.powerOff();
+
+        // Assert
+        assertFalse(phone.isOn());
+    }
+
+    @Test
+    public void assertChargeWorksCorrectly() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = 128;
+        int batteryLife = 75;
+
+        // Act & Assert
+        Phone phone = new Phone(brand, model, storageGB, batteryLife);
+        phone.charge(24);
+
+        assertEquals(99, phone.getBatteryLife());
+        phone.charge(24);
+        assertEquals(100, phone.getBatteryLife());
+    }
+
+    @Test
+    public void assertUseBatteryLifeWorksCorrectly() {
+        // Arrange
+        String brand = "Apple";
+        String model = "iPhone 14";
+        int storageGB = 128;
+        int batteryLife = 75;
+
+        // Act & Assert
+        Phone phone = new Phone(brand, model, storageGB, batteryLife);
+        phone.useBattery(25);
+
+        assertEquals(50, phone.getBatteryLife());
+        phone.useBattery(100);
+        assertEquals(0, phone.getBatteryLife());
+    }
+}