I examined an Anker energy financial institution with a retractable USB-C cable and quick charging speeds, and it is so nice that it is already changed my favourite transportable charger

As an example, I’ve been using it to charge the Motorola Razr Ultra 2025, which supports a 68W charging speed. With a 100W+ wall charger, the Razr’s 4,700mAh battery tops up in just 40 minutes. Here’s how quickly the phone charges from 0% to 100% using both the older and newer Anker Nano portable chargers:

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Anker Power Bank

A1638

A1259

0-50%

22 minutes

30 minutes

0-100%

49 minutes

1h 5m

Remaining

49%

42%

As you can see, the newer model charges the Razr battery in less than an hour, while I have to wait over an hour with the older model. It’s not a huge difference, but any charging speed improvements are welcome, especially when dealing with larger batteries.

Both models also differed in the amount of capacity they had left after providing the Razr with a full charge, with a difference of 7%. Of course, this could also be due to the age of the older charger, resulting in a reduced capacity. Therefore, don’t expect two full charges on phones with larger batteries, but you will still get a decent second charge.

Of course, you can charge multiple devices at once, which is also convenient, but the charging speed is significantly reduced, especially when charging three devices simultaneously. Therefore, I would only utilize this option as a last resort.

And if you don’t have a particularly fast wall charger with you, you can use the A1638 as a sort of intermediary, charging it with whatever wall adapter you have while charging your smartphone with the power bank for faster speeds.

(Image credit: Derrek Lee / Android Central)

When it comes to charging both power banks themselves, that will take significantly longer, given their capacities and the fact that they top out at 30W input. The A1638 takes a bit longer to reach a full charge, taking just under two hours to go from 0% to 100%, while the older A1259 model takes only an hour and a half.

However, this could once again be a result of reduced capacity thanks to two years of usage, but it is a significant difference. That said, I feel it hardly matters when these are used as backups; therefore, I can leave them to charge overnight and not have to worry about charging them again until they’re depleted.

Check your charge

(Image credit: Derrek Lee / Android Central)

The older model came with a handy display that showed how much time you had left to charge. The newer model has this too, but the display is actually much more useful. It displays the port you’re using and the amount of charge it’s providing (or receiving) in real-time, allowing you to observe how it fluctuates as you charge a device for an extended period.

You can also cycle through different screens to view the battery health of the power bank, the number of charging cycles it has undergone, and its battery temperature/charging performance. Anker says its ActiveShield safety system conducts 6 million daily temperature checks “to prevent overheating and extend battery life.”

Given how long I’ve owned the A1259 model, I believe that additional display information would be helpful in assessing its performance over the years.

That said, the older Anker Nano Power Bank (A1259) remains a great choice, as it offers the same battery capacity, a built-in USB-C cable, and a display to monitor your charging progress. And given that some flagship phones like the base Galaxy S25 support 25W to 30W wired charging or less, this will be a good option.