🔋 Battery Runtime Calculator
Estimate how long your battery will last under load. Essential for drones, IoT devices, and solar setups.
Lead Acid batteries should not be discharged below 50% to prevent damage.
💡 Expert Tips
Temperature matters. Batteries perform poorly in the cold. A Li-ion battery at 0°C (32°F) might only deliver 80% of its rated capacity. At -20°C (-4°F), it might drop to 50%.
The "C-Rate" effect. If you discharge a battery very fast (e.g., draining a drone battery in 5 minutes), you get less total energy out of it due to internal resistance losses. This calculator assumes a moderate discharge rate (0.2C - 1C).
Sleep Mode is key for IoT. An ESP32 microcontroller uses ~240mA when active (Wi-Fi on), but only 0.01mA in Deep Sleep. If your device sleeps 99% of the time, your battery life goes from hours to months.
"People always forget the 50% rule for Lead Acid batteries. They buy a 100Ah battery thinking they have 100Ah. They don't. They have 50Ah usable. This calculator handles that logic correctly."