Frequently Asked Questions
Please read the latest questions and answers to help familiarize you with the Energizer® products. If you can’t find an answer to your question, please contact us.
Battery Capacity vs. Rated Capacity (Usable Power)
Rated Capacity (Usable Power) is the energy your power bank can actually deliver to your devices. Due to energy loss during charging, usable power is always lower than the labeled battery capacity.
- Voltage Conversion: The internal battery operates at 3.7V, but most devices require 5V, leading to energy loss during conversion.
- Heat and Circuit Loss: Energy is consumed by the power bank’s circuits and dissipated as heat.
- Real-World Factors: Cable quality and device type can further reduce efficiency.
- Battery Capacity (Wh) = Capacity (mAh) × Voltage (3.7V) ÷ 1000
- Example: A 10,000mAh battery = 10,000 × 3.7 ÷ 1000 = 37Wh
Rated capacity is the actual energy a power bank delivers to devices and is calculated as:
- Rated Capacity (mAh) = Battery Capacity (Wh) ÷ Output Voltage (5V) × Efficiency (%)
- Example: A 10,000mAh battery with 85% efficiency = 37 ÷ 5 × 0.85 × 1000 ≈ 6,290mAh
Yes! Use this formula for a quick estimate:
Rated Capacity ≈ Battery Capacity × 3.7 ÷ 5 × Efficiency (%)
Charging Your Power Pack
When you connect your portable charger to your device, press the power button, your portable charger’s LED lights will turn on, indicating the amount of charge left, and your device should show that it is charging. Please make sure the device is compatible with your power pack.
