Power Banks Explained: Choosing the Right mAh and Wattage

A power bank is one of the most useful accessories you can own in Kenya. The trick is matching one to your device and to how you will use it.

Understanding capacity

Power banks are rated in milliamp-hours (mAh). You will never get all of it. Voltage conversion and heat mean the usable amount is usually around 60 to 70% of the rated capacity when charging a phone.

So a 10,000mAh power bank may deliver around 6,000mAh or so to your phone. That is often around one to two full charges for a typical smartphone.

Which size?

• 10,000mAh: compact and good for daily carry. Our Oraimo and UGREEN ranges include many.
• 20,000mAh: great for long trips or several devices.
• 27,000mAh and above: great for travel or outages, but heavy.
• 40,000 to 50,000mAh: like the larger Oraimo models, these are for extended power cuts rather than a pocket.

Fast charging

Look at the output wattage. 20W suits most iPhones. 25W to 45W suits many Android phones with PD or PPS. Larger wattages support tablets and laptops. Our charger guide explains these standards.

Laptop charging

Not all power banks can charge laptops. For USB-C laptops, look at high-wattage models such as the UGREEN Nexode range, the Baseus Adaman or the Oraimo PowerJet. Check that the wattage meets your laptop's requirements.

Older laptops with barrel-shaped chargers may need a special adapter or cannot use a USB-C power bank at all.

Features worth considering

• Built-in cables: convenient, as you have one less item to forget.
• Magnetic charging: useful with MagSafe-compatible iPhones, such as UGREEN's magnetic power bank and Oraimo's OPB-7102W.
• Digital display: shows remaining charge accurately.
• Pass-through charging: charge the bank and a device at once, but this can generate heat.

Flying with a power bank

Most airlines allow power banks only in hand luggage. Limits generally depend on watt-hours. Many airlines limit banks to 100Wh without approval, and that is about 27,000mAh at standard battery voltage. Check your airline's rules before travelling.

Safety

Avoid unbranded batteries with extreme claims. Stop using any power bank that swells, gets very hot, or smells unusual. Do not leave them in hot cars.

For bigger needs, see portable power stations. If you drive often, check out car chargers and phone holders.