Battery Life Calculator

Privacy First: Your files are processed securely. Whenever possible, processing happens in your browser and files are never stored on our servers.

Calculate battery runtime from mAh and current draw with efficiency factor. Presets: smartphone, laptop, power bank, car battery. Power-to-current converter. Solar charging tab.

How to Use

  1. 1Click a device preset or enter battery capacity (mAh or Ah) and voltage
  2. 2Enter the device current draw (mA or A) - or use the Power tab to convert from watts
  3. 3Adjust the efficiency factor (default 85%) for real-world losses
  4. 4Click Calculate Battery Life to see runtime in hours and minutes, Wh, and kJ
  5. 5Solar Charging tab: enter panel wattage, sun hours, and efficiency to estimate charge time

Features

  • Runtime from mAh/Ah and current draw (mA/A) with efficiency factor
  • Device presets: smartphone, laptop, power bank, car battery
  • Energy in watt-hours (Wh) and kilojoules (kJ)
  • Power-to-current converter (W + V → A)
  • Solar charging time estimate (panel watts + sun hours)
  • 100% browser-based

Frequently Asked Questions

Guest PlanUpgrade
Operations today0 / 3
5 MB max fileNo batch
Upgrade for more

Community Feedback

Like

00

Total Rating

No ratings yet

Reviews

No reviews yet. Be the first!

Rate & Review

Was this tool helpful?

Rate this tool:

Write a Review

0/500

/ share this tool