We know that the more energy a power bank stores, the more times it can charge a device. How do you know the amount of energy a power bank contains? We measure a battery's electrical capacity by its mAh (milliamp Hours).

As technology thrives and demand increases, we're beginning to see power banks on the market with a battery capacity of up to 30000mAh. In contrast, the size of the average smartphone battery tends to be under 6000mAh.

Most of us assume that the higher the power bank’s capacity, the better it is, but is this true?

Are High Capacity Power Banks Better Than Small Power Banks?

The advertised battery capacity is not the actual size.

The biggest myth about cell phone power banks is that its power is listed in the technical specifications. If you see 10000mAh on a power bank or its user manual, you may assume it can charge your iPhone 11 (3110mAh) at least three times. Unfortunately, it's going to run out of juice before the third charge completes because the real capacity is only about two-thirds the size of the advertised volume. Realistically, a 10000mAh power bank only has around 6000~7000mAh of power to charge up your iPhone 11.

The advertised capacity is just the theoretical value based on the battery cells. Power bank manufacturers often list the theoretical size as an advertisement, making their not-so-high-capacity power banks look better than they are.

False theoretical capacity

Worse still, some manufacturers sell power banks with fake theoretical capacity.

The most powerful power bank you can find on Amazon is 72000mAh and that’s over $150. If you search "100000mAh power banks" online, you will see that eBay and Aliexpress are selling them, but if you take a closer look, you'll find a scam. No well-known brands are making 100000mAh power banks, and those sold on e-commerce sites are suspiciously cheap. A 10000mAh power bank costs around $15~$30, making little sense if the price for a power bank with energy ten times higher is the same.

Not only are they not as powerful as advertised, but they pose a significant security risk. These power banks are highly likely cheap because manufacturers use cheap and inadequate electronics, increasing the risk of combustion.

Too bulky to be a portable power bank.

Given that the higher the capacity of a power bank, the bulkier it is, a real 100000mAh power bank is almost impossible to fit into a pocket.

Some devices can hold more than 100000mAh, but they are not really "power banks." Take the Anker 120000mAh PowerHouse, for example, an electric power generator that can charge a laptop a few times, or power a mini-fridge for 7+ hours. It's much more powerful and more substantial than the traditional power bank.

What Are the Downsides of High Capacity Power Banks?

Extra weight

A 10000mAh power bank weighs approximately 220-250g, while a 30000mAh can easily exceed 600g, about the same weight as two cans of cola. Although high capacity power banks are ideal power sources, especially when you are out for a long trip, you also have the additional weight.

Longer charging time

It takes longer to charge a cell phone if it has a bigger battery, similarly, to store more energy, a power bank requires longer to charge. If the input is 10W (5V/2A), which is the case for many power banks, it requires at least 5 hours for a 10000mAh power bank to charge fully. This is not very convenient, especially when you remember to charge it at the last minute.

Flight restrictions

You may already know that you will be asked about power banks when you check-in at an airport. Power banks are only allowed in carry-on baggage, and they should not exceed 100 watt-hours (Wh) per battery. You will need to seek approval from an airline if your power bank has between 100~160Wh, inevitably prolonging the check-in process.

Watt-hours is the number of watts the power bank can supply per hour. Watt-hours = (capacity)/1000 x (nominal voltage). The common nominal voltage for power banks is 3.8V; therefore, a 10000mAh power bank is 38Wh. 100Wh equals to 26315mAh (3.8V).

Are High Capacity Power Banks Even Necessary?

High capacity power banks are great, but there's often a catch. They are not for everyone, and not suitable for every situation. For those who want to go camping with numerous electronic devices, large batteries are the first choice. On the other hand, if you commute to work every day, there's no need to carry a bulky power bank. Charge your cell phone at home or the office, and if you start with a full battery, your mobile should survive the journey home.

Now comes the big question:

How do you make sure your phone battery is always full before you hit the road?

Most of us won't pull out our charging cable right after sitting at the desk, while the phone is still showing 70% of battery. However, after taking calls, checking Facebook, and playing a game on your lunch break, the phone is down to 20% by the time we leave.

You may want to charge your phone whenever possible, but it's hard to change your daily routine.

So, what's the best solution?

The trick is to use a wireless charger that gradually encourages you to charge your phone, such as the MagEZ Slider 2. The MagEZ Slider 2 is detachable 3-in-1 wireless charger that can charge iPhone, AirPods, and Apple Watch simultaneously. The MagSafe power bank charges your iPhone 12, iPhone 13 and iPhone 14 at 5W/7.5W. When you don't need to charge on the go, slide the power bank into the MagEZ Slider dock, so you won't misplace or forget to charge it. When you need to charge on the go, simply slide it out, snap it to your phone, and rest assured that your phone will be active all day.

Have a long commute? Emergency?

If you happen to be a smartphone addict or have a long commute, your phone may shut down before you can access a power source. With the MagEZ Slider, this is no longer a problem as it doubles as a lightweight, magnetic power bank. When you need battery backup, pull your phone out with the power bank, and you are good to go. 

In addition, the power bank will always be ready for your travel. With the dedicated dock, you won't misplace it or forget to charge it anymore. 

Conclusion

Think twice before purchasing a high capacity power bank because you may find that it doesn't work as expected, or you don't even need it. For many, high capacity power banks are not necessary. Charge your smartphone whenever you can by using the MagEZ Slider 2, and you'll never be worried that your phone will die. Just turn it into a magnetic wireless power bank, and you can rest assured that your phone can last until you have access to power.