Sky Strike 3DPlayBattery Life Calculator
Battery life (hours) = capacity (mAh) × efficiency ÷ device current (mA). A 3,000 mAh battery powering a 300 mA device at 85% efficiency lasts about 8.5 hours.
Updated · by ViralScopeHub Team
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How to use: Enter the battery capacity (mAh or Wh), the device draw (mA or W), the voltage if you use Wh or W, and an efficiency (85% is typical).
Estimate how long a battery or power bank will run a device, from its capacity and power draw.
How battery life is calculated
Hours = mAh × (efficiency ÷ 100) ÷ mA. To convert Wh to mAh: mAh = Wh × 1000 ÷ volts. To convert watts to mA: mA = W × 1000 ÷ volts. Efficiency covers losses in converters and the fact that batteries are not fully drained.
Power banks
Power bank capacity is rated at the internal cell voltage (3.7 V), while phones charge at 5 V or more, so you get roughly 60–70% of the rated mAh into your phone.
VSH take: real devices change their draw constantly, so treat the result as an estimate.
Examples
- 3,000 mAh, 300 mA, 85%: 3,000 × 0.85 ÷ 300 = 8.5 hours.
- 50 Wh laptop battery, 10 W: At 85% efficiency: about 4.25 hours.
- 2,000 mAh, 20 mA sensor, 90%: 90 hours (3 days 18 h).
Frequently asked questions
How long will a 10,000 mAh power bank last?
It depends on the device. Charging a 4,000 mAh phone, expect about 1.5–2 full charges.
What efficiency should I use?
80–90% is typical for most devices.
Why do I need voltage?
To convert watt-hours or watts into mAh or mA.
Is this exact?
No. It is an estimate; temperature, age and changing loads affect real battery life.
