Power Your Projects with Confidence

Building an IoT device? Planning a camping trip with portable electronics? Our Battery Life Calculator estimates runtime based on battery capacity and power draw. Enter milliamp-hours (mAh) and current consumption (mA) to see exactly how long your device will run. Essential for makers, engineers, and anyone designing portable systems that need to last!

The Simple Math (With Caveats)

Basic formula: Life (hours) = Capacity (Ah) ÷ Current (A). But reality is more complex! This calculator accounts for efficiency factors and notes that high discharge rates reduce effective capacity (Peukert's Law). A 2000mAh battery at 100mA load won't always last exactly 20 hours—temperature, battery age, and discharge curves all matter.

Battery Fun Fact: Lithium-ion batteries can handle 300-500 charge cycles before significant degradation. That's why your phone battery seems weaker after 2 years!

Battery Life Calculator