External battery: our comparison for Android and iPhone smartphones


While the arrival of fast charging on our phones has made it more difficult to run out of fuel, an electrical outlet is not always within reach. That’s why the good old external batteries – or power banks in Shakespeare’s language – haven’t had their last word.

On the contrary, they evolve, slowly gaining in capacity, but above all by adopting new standards. Most of them are now equipped with a USB-C connector and a form of fast charging while others offer Qi wireless charging.

Think carefully about what you will use it for. It can be tempting to buy the biggest capacity possible, but it won’t do you much good if you never take it with you because it’s top heavy or bulky. If you just want to avoid the phone running out of power at the end of the evening, a small 5000 mAh battery that fits in your pocket will be more interesting than a brick capable of recharging a tablet several times. The best battery is above all the one you have with you!

More generally, we strongly recommend that you build up a “  charging pocket  ” including the battery and all the necessary cables. For the latter, do not hesitate to invest in short models (around 30 cm). They are less bulky while still being long enough to continue using a charging device. To get the most out of your external battery, also use a USB Power Delivery charger that can charge it quickly.

Here is our comparison of the best external batteries. If you are interested in induction chargers, you will find what you are looking for in our dedicated guide .

Anker PowerCore Essential 20000 PD: power above all else

Today, there are external batteries that can generate a current powerful enough to recharge a computer, compatible tablets or other devices with USB-C Power Delivery technology. This is particularly the case for MacBooks in USB-C, the iPad Pro, the Nintendo Switch and even some fast-charging smartphones such as Google Pixels or iPhones (since the iPhone X / 8/8 Plus generation, via a USB-C Lightning cable).

This is the case with the Anker PowerCore Essential 20,000 battery. It is equipped with a USB-C port compatible with Power Delivery, which allows it to deliver a power of up to 18 watts. It can thus recharge the vast majority of USB-C devices optimally. Plus, if you charge it with a USB-C Power Delivery compatible charger itself, it will also benefit from the technology and regain its full color in just 4 hours. It is very fast for its capacity.

It also has a USB port, which gives it the possibility of connecting a second traditional device by adapting its power so as not to damage its components.

Why do we recommend this product?

  • 20,000 mAh: it can recharge the majority of smartphones up to 4 times
  • USB-C Power Delivery compatible to charge a PC, a tablet or a Switch
  • USB-C cable included

We do not always need to fill several devices in a row. If you are just looking to give your phone a little boost to end the day, it is better to choose a compact battery that you can easily carry in your pocket.

The Anker PowerCore 5000 mAh perfectly fulfills these specifications. Cylindrical and weighing only 136 grams, it won’t overload you. On the power side, its 5,000 mAh will be enough to fully recharge the vast majority of smartphones. The connection could not be more basic with a micro-USB input and a classic USB output with a power of 2 W. No fast charging on the menu, but difficult to complain given the price. However, we would like Anker to offer us a USB-C version in the future.

The price of this battery is just as small as its size, which is why it is essential for us to always carry with you.

Why do we recommend this product?

  • Very small and light
  • Able to fully charge all phones
  • Cheap and reliable

Anker PowerCore III 10000 Wireless: wired or wireless

A little more expensive than a traditional 10,000 mAh battery, this PowerCore III is distinguished by the presence of Qi induction charging. On the shape we remain on the very classic: a slightly textured black pad a little thicker than average due to the presence of the induction charger. The machine is solid and comes with a USB-C cable and a carrying pouch; it’s not much, but we appreciate the attention.

The connection is provided since beyond Qi we have the right to USB-C and conventional USB. On the output power side, it will be 18 W Power Delivery with a cable and 10 W Qi if you do not want a wire on the leg. Interesting detail: a small hook is integrated and allows the battery to serve as a stand for the phone when it is placed in landscape mode. Convenient for quietly watching series on the train for example.

A good battery, versatile and with enough power for the vast majority of uses.

Why do we recommend this product?

  • Qi and Power Delivery compatible
  • Small accessories provided
  • An excellent quality / price ratio

Apple MagSafe Power Bank: for iPhone 12


If you are the lucky owner of a last generation iPhone, Apple has finally drawn its vision of an external battery. The latter is MagSafe compatible and is therefore able to fit on the back of a compatible iPhone. Contrary to what some might fear, it holds up surprisingly well and does not fall off in conventional use. If it corresponds perfectly to the dimensions of the iPhone mini 12, it of course works without problem with the rest of the range. If you are using a cover, it will most likely have to be removed, as the magnets have difficulty, even with fairly thin plastic.

The charging itself uses the Qi 5W standard. This means that you will be able to charge AirPods or any other device not bearing the apple sign. Apple has chosen to equip its machine with a Lightning connector, which is an advantage and a disadvantage. On the one hand, this limits the number of cables needed, but on the other hand, you won’t be able to charge it with a friend’s USB-C cable.

The big black point of this battery is its capacity of 1460 mAh. So, admittedly, it is very efficient with its 11.13 Wh, but that will not even be enough to fully charge an iPhone 12 mini, let alone the iPhone 12 Pro Max. Note that when connected to a sufficiently powerful charger it acts as a Qi charger capable of a power of 15 W.

Apple gives us here a product of which it has the secret, the MagSafe battery is expensive and its capacity limited, but we have to admit that it will be perfectly grafted to an iPhone 12 to avoid being stranded in the middle of the day.

Why do we recommend this product?

  • Perfect iPhone integration
  • Impeccable finish
  • Can be used as a Qi charger when plugged in

The alternative: Anker PowerCore Magnetic 5K

If the price of the Apple battery turns you off or you would like a larger capacity, this MagSafe model from Anker is a good choice. So, of course, it is bigger and less well finished, but its 5000 mAh allow you to refuel an iPhone several times. We also appreciate its USB-C connector which allows it to be used as a traditional power bank .

Omnicharge Omni 20+ USB-C: the most successful

Sometimes you just need to be able to charge absolutely everything without worrying about it, and that’s where the Omni 20+ shines. Much more expensive than most of its competitors of similar capacity, it is however much more versatile.

Its USB-C port is indeed 100 W Power Delivery compatible! In practice, it is therefore capable of recharging a MacBook Pro at full speed while the latter is fully charged. A performance that was until then reserved for sector chargers.

It can also power three other devices in parallel since it is equipped with two USB connectors (which can serve as a hub) and a 10 W Qi wireless charging module. The icing on the cake: it is rechargeable via USB- C PD 45 W, enough to fill up 20,000 mAh in less than three hours.

If you need a universal battery that can charge even the most demanding devices, look no further.

Why do we recommend this product?

  • Capable of delivering up to 100W
  • Wireless charging
  • Big capacity

What to know before buying an external battery

How do I calculate the number of recharges for my phone?

The capacity of a battery is expressed in mAh, like that of phones, but don’t think that dividing the first by the second is enough to get the number of recharges. It would be too simple. As is often the case with electricity, the reality is more complex, it is necessary to take into account the voltage of the batteries and the performance of the external battery. The scholarly formula is as follows:
(external battery capacity x smartphone battery voltage / external battery voltage) x smartphone efficiency / capacity.
Now let’s take a typical example: (10,000 x 3.7 / 5) x 0.85 / 4000. Which gives us about 1.5 recharges in this case, with 16,000 mAh you will have about 2.2. It will be necessary to calculate according to your smartphone, but with this formula, it is easy to understand that 5000 mAh is not enough to fully recharge a terminal of the same capacity.

What are the trusted brands?

When it comes to electricity, it is recommended to pay special attention to the quality of the products for safety reasons. It should be remembered that the batteries are liable to ignite in the event of a malfunction. In practice, these rare cases, but we recommend, however, to go in general towards “big brands” such as Anker or RavPower or even Aukey which are well-known on the market. Unfortunately several of them have been banned from Amazon and are therefore difficult to find at this time.

What are the precautions for using an external battery?

For safety reasons, it is important to remember the usual precautions: do not use it or leave it in direct sunlight or in general in poorly ventilated areas. This means, for example, not to use it or recharge it under a duvet. Obviously, it should not be punctured and even less thrown into the fire.