How to Calculate How Many Times a Power Bank Can Charge Your Device

One of the most common questions when buying a power bank is: “How many times can this charge my phone, tablet, or laptop?” Understanding the math behind it helps you choose the best power bank for your needs and ensures you stay powered throughout the day.

With Qyram Power Banks, you get high-capacity, reliable devices that make charging multiple gadgets simple, but knowing how to calculate usage helps you plan better.

Step 1: Know Your Device’s Battery Capacity

Battery capacity is measured in milliamp-hours (mAh) or watt-hours (Wh). Most smartphones list capacity in mAh:

• iPhone 14: ~3,279 mAh
  
• Samsung Galaxy S23: ~3,900 mAh
  
• iPad Mini: ~5,124 mAh
  

Laptops and some tablets usually list in watt-hours (Wh).

Tip: You can find your device’s battery capacity in the specifications section of the manufacturer’s website.

Step 2: Check Your Power Bank’s Capacity

Power banks also have their capacity listed in mAh or Wh. For example:

• Qyram PD60 20,000 mAh (USB-C PD)
  
• Qyram SolarPro 20,000 mAh (solar-compatible)
  

Important: The actual usable capacity is less than the rated capacity due to energy loss during voltage conversion and internal battery inefficiency. On average, expect 85–90% efficiency.

Step 3: Use the Formula

To calculate the approximate number of charges:

Number of Charges=Power Bank Capacity (mAh)×EfficiencyDevice Battery Capacity (mAh)\text{Number of Charges} = \frac{\text{Power Bank Capacity (mAh)} \times \text{Efficiency}}{\text{Device Battery Capacity (mAh)}}Number of Charges=Device Battery Capacity (mAh)Power Bank Capacity (mAh)×Efficiency

• Efficiency is typically 0.85 (85%) for realistic estimation.
  

Example: Charging an iPhone 14 with a Qyram PD60 20,000 mAh:

Number of Charges=20,000×0.853,279≈5.2\text{Number of Charges} = \frac{20,000 \times 0.85}{3,279} \approx 5.2Number of Charges=3,27920,000×0.85≈5.2

So, the power bank can charge your iPhone about 5 times.

Step 4: Account for Device Power Requirements

Some devices require higher voltage (like tablets or laptops) or draw more power.

• Qyram power banks like PD60 support USB-C Power Delivery (PD), which can handle higher-wattage devices safely.
  
• For laptops, calculate in Wh instead:
  

Number of Charges=Power Bank Capacity (Wh)×EfficiencyDevice Battery Capacity (Wh)\text{Number of Charges} = \frac{\text{Power Bank Capacity (Wh)} \times \text{Efficiency}}{\text{Device Battery Capacity (Wh)}}Number of Charges=Device Battery Capacity (Wh)Power Bank Capacity (Wh)×Efficiency

Example: Charging a 50 Wh laptop with a 74 Wh (20,000 mAh at 3.7V) power bank at 85% efficiency:

74×0.8550≈1.25\frac{74 \times 0.85}{50} \approx 1.255074×0.85≈1.25

You get about 1 full charge plus a partial charge.

Step 5: Factor in Real-World Conditions

Several factors can reduce the number of charges:

• Age of the power bank: Batteries degrade over time.
  
• Cable quality: Poor-quality cables reduce efficiency.
  
• Simultaneous charging: Charging multiple devices reduces total available power.
  
• High-drain apps: Gaming, streaming, or camera use consumes more battery during charging.
  
  

Step 6: Quick Reference Table

Tip: Qyram banks with multiple ports can charge more than one device at a time, but total power is shared.

Why Qyram Power Banks Excel

• High-capacity models like PD60 and SolarPro ensure multiple charges for phones, tablets, and laptops.
  
• Smart charging circuitry maximizes efficiency and protects devices from overcharging.
  
• Fast-charging support reduces downtime between charges.
  

Final Thoughts

Calculating how many times a power bank can charge your device is simple once you know the device battery, power bank capacity, and efficiency factor.

With Qyram Power Banks, you can confidently choose the right model to meet your charging needs, whether you’re commuting in Dubai, traveling across the UAE, or working remotely. A little math goes a long way in planning your portable power strategy.