Whether you’re operating ham radio equipment from a mountaintop, setting up a temporary field station, or building a portable electronics project, understanding how long your gear can run on battery power is essential.

That’s where the 9M2PJU Battery Drain Calculator comes in — a clean, intuitive, and mobile-friendly web tool designed to help you estimate your device’s runtime based on actual usage conditions.

🎯 Why It’s Useful

This calculator is especially helpful for:

• Amateur radio operators planning SOTA, IOTA, or portable operations
• Emergency responders preparing backup power setups
• Makers & engineers working on low-power IoT devices
• Anyone who wants a quick and realistic estimate of how long their battery will last

🧮 What It Calculates

By entering your battery’s capacity (mAh) and the device’s drain current (mA), the calculator gives you an estimated runtime in hours and minutes.

For more accurate results, you can also enter:

• Battery voltage (V)
• Duty cycle (%) – the percentage of time your device is active
• Efficiency (%) – to account for losses in power conversion or circuitry

⚙️ Key Features

• ✅ Simple and clean UI — mobile and desktop friendly
• 🌙 Dark mode support
• ⚡ Real-world adjustments for efficiency and duty cycle
• 📏 Instant runtime estimates in hours and minutes
• 🛠️ Designed with practical use in mind

🧪 How Accurate Is It?

This tool offers a best-case scenario based on the inputs provided. It includes a helpful disclaimer reminding users that actual results may vary due to battery age, temperature, voltage sag, and other real-world factors.

🔗 Try It Now

You can access the calculator for free at:

👉 https://battery.hamradio.my

No downloads, no signups — just useful information when you need it.