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Master Battery Power Calculations

Calculate charging times, battery life, and power consumption with our free tools. Learn everything about batteries, from smartphones to electric vehicles.

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Accuracy Rate
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Power Calculator
Device Power: 65W
Battery: 50,000 mAh
185 Wh
Capacity
2.8 hrs
Runtime

Everything You Need for Battery Calculations

From basic smartphone battery life to complex industrial power systems, our tools and guides cover all your power calculation needs.

Power Calculator

Calculate charging time, runtime, and energy consumption for any device. Supports everything from phones to electric cars.

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Educational Guides

Learn about battery types, chemistry, safety, and best practices. From beginner to expert level content.

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Multiple Tools

Battery capacity converter, cost calculator, lifespan estimator, and more specialized tools for professionals.

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Popular Battery Calculations

See what others are calculating and get quick answers to common questions.

📱
iPhone 15 Pro
Battery: 3,274 mAh (12.1 Wh)
Screen Time: 15-20 hours
Charging: 1.5 hours (20W)
💻
MacBook Pro 16"
Battery: 100 Wh
Runtime: 8-12 hours
Charging: 2 hours (140W)
🚗
Tesla Model 3
Battery: 75 kWh
Range: 358 miles
Charging: 8.5 hours (11kW)

Understanding Battery Power

What is Watt-Hour (Wh)?

Watt-hours measure energy capacity - how much work a battery can do. It's calculated by multiplying voltage (V) by amp-hours (Ah). For example, a 5V battery with 10,000mAh capacity contains 50 Wh of energy.

Battery Runtime Factors

Runtime depends on device power consumption and battery capacity. A 50Wh battery powering a 10W device runs for 5 hours. However, real-world factors like screen brightness, wireless connectivity, and temperature affect actual runtime.

Charging Speed Explained

Charging time equals battery capacity divided by charger power, accounting for efficiency (typically 80-90%). Fast charging uses higher wattage but may generate more heat and affect long-term battery health.

Battery Safety Tips

Always use certified chargers, avoid extreme temperatures, and don't fully discharge lithium batteries regularly. Store batteries at 40-60% charge for long periods, and replace them when capacity drops below 80% of original.

Frequently Asked Questions

Our calculations are based on standard electrical formulas and are highly accurate for theoretical values. Real-world performance may vary due to factors like temperature, battery age, device efficiency, and usage patterns. We account for typical charging efficiency (80%) and provide conservative estimates.

mAh (milliamp-hours) measures charge capacity, while Wh (watt-hours) measures energy capacity. To convert: Wh = (mAh × Voltage) ÷ 1000. Wh is more useful for comparing batteries across different devices because it accounts for voltage differences.

This is called "trickle charging" or "constant voltage charging." To protect the battery and prevent overheating, charging speed reduces as the battery approaches 100%. Most fast charging occurs between 0-80%, with the final 20% taking much longer.
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