battery_tracker/docs/FSD.md

Battery Tracker - Functional Specification Document

1. Overview

Battery Tracker is a personal web application designed to help users manage their rechargeable battery inventory. It solves the common problem of losing track of batteries that are placed in rarely-used devices.

2. Problem Statement

Users with multiple rechargeable batteries often:

• Forget which device contains which batteries
• Cannot quickly determine how many batteries are available
• Lose track of batteries currently being charged
• Have no centralized way to manage battery inventory

3. Core Features

3.1 Battery Type Management

• Define battery form factors (AA, AAA, 18650, CR2032, etc.)
• Define battery chemistries (NiMH, Li-ion, LiFePO4, etc.)
• Associate brands with battery types and chemistries
• Track total quantity per brand-type-chemistry combination

3.2 Battery Status Tracking

Each brand-type-chemistry combination can have batteries in three states:

Status	Description
Available	Batteries in storage, ready for use
In Use	Batteries currently placed in a device
Charging	Batteries currently being recharged

3.3 Device Management

• Create and manage a list of devices (keyboard, mouse, remote, flashlight, etc.)
• Assign batteries to devices with quantity
• Quick view of which device has which batteries

3.4 Quick Actions

• Move batteries between states (Available -> In Use -> Charging -> Available)
• Batch operations for multiple batteries
• Quick "return to storage" action when removing from device

3.5 Dashboard

• Overview of all battery inventory
• Quick status summary (X available, Y in use, Z charging)
• Low stock alerts (optional)

4. User Stories

US-01: Add Battery Type

As a user, I want to add a new battery brand-type-chemistry combination so I can track my inventory.

Acceptance Criteria:

• Can select from predefined form factors (AA, AAA, 18650, etc.) or add custom
• Can select from predefined chemistries (NiMH, Li-ion, etc.) or add custom
• Can enter brand name
• Can set initial quantity and status

US-02: View Inventory

As a user, I want to see all my batteries at a glance so I know what's available.

Acceptance Criteria:

• Shows all brand-type-chemistry combinations
• Displays count per status (available/in-use/charging)
• Filterable by type, brand, or chemistry

US-03: Assign to Device

As a user, I want to assign batteries to a device so I can track where they are.

Acceptance Criteria:

• Select from existing devices or create new
• Specify quantity being assigned
• Automatically decrements "available" count

US-04: Return from Device

As a user, I want to mark batteries as returned from a device so they're back in inventory.

Acceptance Criteria:

• Can return all or partial quantity
• Choose destination: available or charging
• Updates device's battery assignment

US-05: Manage Charging

As a user, I want to track which batteries are charging so I know what will be available soon.

Acceptance Criteria:

• Move batteries to charging status
• Mark charging complete (moves to available)
• Optional: track charging start time

5. Data Model (Conceptual)

BatteryType (Form Factor)
├── id
├── name (AA, AAA, 18650, etc.)
└── isCustom

Chemistry (Battery Chemistry)
├── id
├── name (NiMH, Li-ion, LiFePO4, etc.)
└── isCustom

Brand
├── id
└── name

BatteryGroup (Brand + Type + Chemistry combination)
├── id
├── brandId
├── typeId
├── chemistryId
├── availableCount
├── chargingCount
└── notes

Device
├── id
├── name
└── description

DeviceBattery (Junction)
├── deviceId
├── batteryGroupId
├── quantity
└── assignedDate

6. UI/UX Requirements

6.1 Design Principles

• Clean, minimal interface
• Mobile-responsive (batteries often managed on-the-go)
• Quick actions accessible with minimal clicks
• Visual status indicators (color-coded)

6.2 Key Screens

1. Dashboard - Overview of all batteries, quick stats
2. Battery List - Detailed view with filtering
3. Device List - All devices and their battery assignments
4. Add/Edit Battery - Form for battery management
5. Add/Edit Device - Form for device management

6.3 Visual Indicators

• Green: Available
• Blue: In Use
• Orange/Yellow: Charging

7. Non-Functional Requirements

• Performance: Page load < 2s
• Data Persistence: All data persisted locally or in database
• Offline Support: Nice-to-have for future
• Browser Support: Modern browsers (Chrome, Firefox, Safari, Edge)

8. Out of Scope (v1)

• Individual battery serial number tracking
• Battery health/cycle tracking
• Multi-user support
• Barcode/QR scanning
• Push notifications
• Battery purchase history