Running out of battery when you need it most is one of the most frustrating experiences in our tech-driven world. Whether you’re commuting, traveling, or camping off-grid, a reliable power bank can be your best companion. But one of the most common questions is: what size power bank do I need?
The answer depends on your device, your habits, and your usage needs. This comprehensive guide will help you determine the best power bank capacity for your laptop, tablet, iPhone, or other gadgets.
What Size Power Bank Do I Need?
Before jumping into numbers, it’s important to understand what “size” really means in the context of power banks. It refers primarily to battery capacity, measured in milliamp-hours (mAh), or sometimes watt-hours (Wh).
1. What Size Power Bank Do I Need for a Laptop?
Laptops typically require much more power than phones. If you're wondering what size power bank do I need for a laptop, consider these:
- Most ultrabooks (like MacBook Air) need 30W–60W input and have internal batteries around 5,000mAh to 10,000mAh at higher voltage.
- To recharge one full time, you'd need a power bank with at least 20,000mAh and 60W USB-C PD output.
For powerful laptops like gaming or workstation models, consider 26,800mAh or even 30,000mAh+ with 100W output. Also, make sure the power bank supports USB-C PD (Power Delivery).
To accurately size your power bank for an iPhone, you first need to know your phone’s battery capacity. Learn how many mAh to charge an iPhone based on the model you use.
2. What Size Power Bank Do I Need for a iPhone?
iPhones have relatively smaller batteries compared to laptops and tablets, but they still benefit from a well-matched power bank—especially when fast charging is a must.
To choose the best size:
- A 5,000mAh power bank can charge most iPhones once.
- A 10,000mAh power bank can provide up to 2 full charges.
- For travel or backup, 20,000mAh is a solid all-day solution.
Make sure the power bank supports USB-C PD or Lightning input for quick top-ups. Newer models like the iPhone 13–15 also support fast charging up to 20W.
3. What Size Power Bank Do I Need for a Tablet?
Tablets usually fall between smartphones and laptops in terms of power needs. If you're asking what size power bank do I need for a tablet, here are some ballpark figures:
- iPads and Android tablets generally have 6,000mAh–10,000mAh internal batteries.
- To charge once or twice, a 10,000mAh to 20,000mAh power bank is ideal.
If you plan to use your tablet heavily while traveling or working, go for the higher range.
4. What Size Power Bank Do I Need for a Earbud or Apple Watch?
Both earbuds and Apple Watches have small batteries, so they don’t require much power. A 5,000mAh power bank can recharge either device multiple times. However, if you often charge them along with your phone, consider a 10,000mAh compact model that supports trickle-charging mode—this ensures safe, efficient charging for low-power gadgets without overloading them.
Power bank sizing depends on what devices you use and how often you recharge on the go. Brands like Veger offer a range of capacities from slim 5,000mAh pocket models to powerful 30,000mAh multi-device chargers—so there’s something for everyone once you know your usage needs. Explore Veger’s full power bank collection to find the right fit for your daily use, travel, or emergency backup.
mAh vs Wh – What Power Bank Size Really Means
Most consumers look at mAh, but watt-hours (Wh) give a more complete picture because they account for voltage.
- mAh: Measures electric charge at a given voltage, usually 3.7V.
- Wh: Measures actual energy and is more consistent across different voltages.
To convert mAh to Wh: (mAh x 3.7) / 1000 = Wh To convert Wh to mAh: (Wh x 1000) / 3.7 = mAh
Still confused about mAh? Check our deep dive on what mAh means on a battery to understand how it affects your charging experience.
Recommended Power Bank Sizes for Common Scenarios
Here are some popular use cases and our recommended size:
- Daily phone use: 5,000mAh–10,000mAh
- Traveling with phone & tablet: 10,000mAh–20,000mAh
- Remote work (laptop + phone): 20,000mAh–30,000mAh with USB-C PD
- Outdoor/camping/multiple users: 26,800mAh+ with solar or AC support
- Emergency backup: 5,000mAh keychain or card-size model
If you’re still unsure, use this rule of thumb: calculate your device’s battery size and multiply by how many charges you want.
What to Consider Beyond Size
While mAh is critical, it’s not everything. Choosing a power bank means also evaluating:
- Output power (W): Laptops need 30W+, phones do well with 18W fast charging.
- Port types: USB-C PD is essential for newer laptops; micro-USB is outdated.
- Build quality: A well-constructed shell protects your device and the cells inside.
- Weight/portability: A 30,000mAh power bank is heavier and bulkier.
- Safety features: Look for overheat protection, short-circuit prevention, and temperature control.
- Charging speed: Quick recharge of the power bank itself saves time.
Common Mistakes When Choosing Power Bank Size
Many users fall into common traps when selecting a power bank. One of the most frequent mistakes is buying a model that's too small—like a 5,000mAh unit—which might only deliver one full charge due to inevitable energy loss during conversion.
Others focus solely on capacity while ignoring output power; for example, a high-capacity bank that only offers 5W output is essentially useless for charging laptops.
On the flip side, overbuying “just in case” can lead to carrying bulky, oversized power banks—like a 30,000mAh model—for lightweight tasks such as charging AirPods or a single smartphone.
Another oversight is failing to check flight limits: purchasing a 50,000mAh power bank might leave you stuck at airport security, as airlines typically restrict anything over 100Wh.
Lastly, trusting unknown or low-quality brands is risky—they may exaggerate capacity and skip essential safety certifications, compromising both performance and safety.
FAQs about What Size Power Bank Do I Need
Is more mAh always better?
Not always. Bigger banks mean heavier size and longer recharge times. Match size to your actual needs.
Is a 20000mAh power bank too much?
Not at all. It’s a great middle ground—enough for most phones and tablets, and some laptops.
Can I carry a 30000mAh power bank in flight?
Check its watt-hour rating. Most airlines allow up to 100Wh (around 27,000mAh). Anything above that needs approval. Read this guide on taking large power banks on a plane to avoid airport issues.
Can I charge multiple devices at once effectively?
Yes, if the power bank supports enough output power and port distribution. Look for dual PD ports or multi-port fast charging.
Wrapping It All Up
Choosing -the right power bank isn’t about getting the biggest number. It’s about matching the battery to your lifestyle.
Whether you’re wondering what size power bank do I need for a laptop, tablet, or iPhone, the answer lies in understanding your actual device usage. Think about portability, power needs, and charging habits.
And if you're looking for a reliable, stylish, and safe power bank with smart output control and airline-approved capacity, Veger offers a range of products from 5,000mAh to 30,000mAh+ designed for every modern need.
So next time your phone hits 1% on a long day out, you’ll be prepared—not panicked.
