How to choose the ideal power bank for your smartphone

Your smartphone's battery never lasts as long as we'd like — and it rarely dies at a convenient time. A good power bank solves the problem, but with so many options on the market, it's easy to buy too much capacity, too little power, or a model incompatible with your phone. In this guide, we explain the essentials for making a good choice.

Capacity: how many mAh do you really need?

Capacity, measured in mAh, determines how many charges you can get from the power bank. For reference, a current smartphone battery is around 4,000 to 5,000 mAh, and there are always energy conversion losses (expect about 65 to 70% real efficiency).

• 5,000 mAh — one complete emergency charge. Ultra-compact, fits in any pocket. Ideal for daily use in the city.
• 10,000 mAh — the sweet spot for most people: two full charges without excessive weight in your backpack.
• 20,000 mAh — for travel, festivals, camping, or intensive use with multiple devices (phone, earbuds, tablet).

At iCase, the Powerbank Rixus Digital Display 5000mAh Black (14.90 €) covers occasional use, while the Powerbank Rixus Digital Display 20000mAh Black (29.90 €) is the companion for long trips.

Charging power: watts matter

It's not enough to have stored energy — it needs to be delivered quickly. A 10W power bank takes twice as long as a 20W or more power bank to charge the same phone. If your smartphone supports fast charging (USB Power Delivery or Quick Charge), choose a power bank that keeps up. The Powerbank Baseus Enerfill FP11 22.5W 10000mAh White (34.90 €), which already includes a USB-C cable, is a good example of fast charging at an affordable price.

MagSafe and wireless charging

If you have an iPhone 12 or newer, a MagSafe power bank eliminates cables entirely: it magnetically attaches to the back of your phone and charges while you use it. It's one of the most practical solutions for those always on the go. The Powerbank InMove with MagSafe 10000mAh - White (19.90 €) combines exactly that with all-day capacity — and the price is one of the most competitive in its category.

Details that make a difference

• Digital display: models like the Powerbank Rixus Digital Display 10000mAh Black (21.90 €) show the exact percentage of remaining battery, instead of vague four luminous dots.
• Ports: check if it has USB-C (the current standard) and how many outputs it offers, in case you want to charge two devices simultaneously.
• Protections: circuits against overcharge, overheating, and short-circuit are mandatory — they protect the power bank and your smartphone.
• Size and weight: more capacity means more weight. For your pocket, stick to 5,000–10,000 mAh.

In summary

For urban use and emergencies, 5,000 to 10,000 mAh is more than enough. For travel and multiple devices, go up to 20,000 mAh. Prioritize fast charging if your phone supports it, and for iPhone, consider the convenience of MagSafe. At iCase, you'll find all these options with a 3-year warranty and national assistance — and for orders over 50 €, shipping is free for mainland Portugal.