Best Slim Power Banks


At Charger Harbor we’ve already chosen what the Best Smallest power banks on the market. Those kind of portable chargers were the best in the category of providing just enough power capacity and being small enough that you could take them anywhere. With that said, they were all nearly different sizes and some were more portable than others.

More importantly, there was a specific category within the Best small power banks that could have their own category and that was the Slim power banks. Slim power banks have their own place in the charging tech world because they’re able to offer a superb portable experience and still hold onto their powerful charging, at least for some that is the case.

A Slim portable charger is very useful because you can always place it into your pocket along with your smartphone and this means that you can charge your smartphone while it’s in your pocket. Although that’s still possible with a cylindrical and small power bank, in this case, it’s simply easier to use.

These Slim power banks have shown the best capabilities when it comes to power and portability. They have proven that just because they’re slim doesn’t mean that their capabilities are any less. These are the best slim power banks on the market.

#1: Viivant Slim Portable Power Bank


There are very few Slim power banks like the Viivant Slim portable charger and this is mainly because of what it has in terms of its charging ports and the power that it’s able to provide.

Power Capacity

Starting with the power capacity first, this power bank is able to offer an initial power capacity of 5,000mAh and that is decreased down to 4,000mAh during charging because some power is lost during charging. With that power capacity, you’ll be able to charge a smartphone about 2 times and that’s about it.

Even though it won’t charge most smartphone too many times, it does a great job at charging even high battery capacity smartphones like the Samsung Galaxy S7 and S7 Edge to their full power capacities.


Okay, so the power capacity does just good enough of a job but the charging that it’s able to deliver is really awesome and bizarre at the same time, we say this because the Viivant power bank has 2 Output charging ports if you’re charging 2 smartphones with the power bank then you can expect a half charge for each of them.

1 Port is able to Output 2.1 Amps of charging speed and that’s actually a really fast charging rate, and then the other one is able to Output 1.0 Amp of charging speed which is quite slow. This means that the power bank has a Max Output Speed of 3.1A and for a Slim power bank to have 2 charging ports is amazing. For the charging ports to have 2.1A and 1.0A charging speed is what makes it phenomenal.


The recharging speed is another reason that this is one of the best slim power banks, with it being able to recharge at 2.0 Amps and this will result in the power bank being able to fully recharge within 4-5 hours.


Then there’s the portable aspect of it with it being the same size as a smartphone. The length of the power bank is 5.4 inches, it has a width of 2.6 inches and the thickness is 0.3 inches. It can easily fit into your pocket alone or along with your smartphone because it’s basically the size of a smartphone.

Holding it and using it, holds no problems either.

Full Review for Viivant Slim Portable Power Bank

Specs of the Viivant Slim Portable Power Bank:

  • Capacity:            Advertised: 5,000mAh             Real Capacity: 4,000mAh
  • Output:      Port 1: 5V/2.1A      Port 2: 5V/1.0A
  • Input: 5V/2.0A via Micro USB Input
  • LED Power Indicators: 4 LED Power Indicators
  • Size: 0.31 x2.7 x 5.4 inches
  • Weight: 5.1 ounces

#2: Anker PowerCore 5000 Slim

This Anker Slim power bank is a slim power bank that not only holds its remarkable functions with it being slim but it’s also the way its design and the way you’re able to use it that makes it more convenient to use.

Power Capacity

The power capacity is able, to begin with, 5,000mAh of power, and then it decreases down to 4,000mAh of power capacity during charging. This kind of Output power capacity is very common among small power banks and especially when it comes to slim power banks.

Just like the Viivant Slim, this Anker PowerCore Slim is going to be able to charge some smartphones 2 times, but a smartphone with a larger than normal battery capacity will be able to charge once or 1.5 times. With that said, it actually has a pretty good power capacity that can either last you a single day or 2 days.


Along with just enough power capacity comes a single Output port that is able to charge at 5V/2.0A, this means that you can charge nearly any smartphone at its max charging speed, except for smartphones that are Quick Charge compatible.

If there’s one thing that is rare but very welcome with small and slim power banks alike, it’s that fast charging is hard to come by with them. However, when it does come by, it’s very welcoming because you can charge your smartphone at a very fast charging speed even with something as portable as this.


Speaking of its portability, this slim power bank does a great job as basically acting as a second smartphone. It’s got a length of 5 inches, a width of 2.5 inches and a thickness of 0.4 inches. It can easily fit into your pocket and if you’re up for it, you can even fit the PowerCore Slim and your smartphone into the same pocket.

The portability aspect of it is great, but that’s not exactly the main attraction.


The main attraction is the way that you can use the PowerCore and how comfortable it is to use. The PowerCore Slim has a curved back that makes it highly ergonomic and easy to hold.

You can stack your smartphone on a rubber side that has indented grooves and this will allow you to answer phone calls while holding onto the power bank and your smartphone at the same time.

Full Review for Anker PowerCore 5000 Slim

Specs of the Anker PowerCore 5000 Slim:

  • Capacity:            Advertised: 5,000mAh             Real Capacity: 4,000mAh
  • Output:      5V2.0A
  • Input: 5V/2.0A via Micro USB Input
  • LED Power Indicators: 3 LED Power Capacity Indicators
  • Size: 5 x 2.5 x 0.4 inches
  • Weight: 4.2 ounces

#3: Jackery Air 6


Sometimes extreme simplicity is the best way to go and that’s what this Slim Jackery Air 6 power bank is able to offer.

This is on the list of the Best Slim power banks because the Jackery Air 6 takes it down to the bare minimum of what a slim power bank is able to offer. At times the bare minimum is all we really need and that’s what this Jackery Air 6 basically is; the bare minimum and by doing so it’s able to excel itself with the way you can use it.

Power Capacity

Starting out with its power capacity, we’ll be honest and say that the power capacity isn’t anything special with it initially being 3,000mAh and it burns down to about 2,500mAh of power capacity during charging.

So I guess it can go without saying but I’ll go ahead and say it anyways is that this power bank is only going to charge your smartphone 1 time and possibly even less. If you have a smartphone with a larger battery capacity, then it likely won’t be able to charge it to its max power level.


Additionally, the charging speed is 5V/1.0A and as a result, it won’t be able to charge most of your devices at their max charging speed but on the bright side, the power bank is able to recharge at 2 Amps and it will be ready at full charge in about 1-2 hours. So even though the power capacity is quite low, you can very likely use this power bank again the same day you used it.


Moving into the portability, it’s the smallest and slimmest power bank on this list. The Jackery Air 6 is 4.6 inches in length, it has a width of 2.4 inches and it has a thickness of 0.3 inches. The weight is only 3.4 ounces.

A Slim power bank like this will have no problems going into your pocket along with your smartphone and we feel that it can very well go anywhere you take it.

All the functional components are the same side and power bank doesn’t even waste any space or take the chance of being bigger than it needs to be by using only one LED power capacity indicator light that changes colors to show different power capacity levels.

Full Review for Jackery Air 6

Specs of the Jackery Air 6 Power Bank:

  • Capacity:                 Advertised Capacity: 3,000mAh        Real Capacity: 2,500mAh
  • Output:  5V/1.0A
  • Input: 5V/2.0A  Via Micro-USB
  • LED Power Indicators: Single LED Indicator with Color Variants
  • Size: 4.6 x 0.3 x 2.4 inches
  • Weight: 3.4 ounces
  • Comes with an Apple Lightning Cable

#4: Aukey 3,600mAh Portable Charger


Lastly, of the best Slim power bank is this Aukey Slim portable charger. It may not be as slim as the other portable chargers within this list but it does well enough by being able to be at the same portability level that the other slim power banks are able to achieve.

Power Capacity

It does a good job at retaining a well-off power capacity by it being initially 3,600mAh and then the actual Output power capacity is 3,000mAh.

This is enough power capacity to charge most smartphones to their full power capacities and we think that it’s one of the best Output power capacities that all small power banks should aim for since many smartphones are able to match up to this amount of power.


On the charging speed side, this is where the Aukey Slim portable charger does well enough and accommodates itself to most smartphones. This is because the Output charging speed is 1.5 Amps and most even though some smartphones can charge faster than this, this charging speed makes sure that most smartphones are able to charge at their max charging speed.

The recharging speed is fast enough with it being 1 Amp and it can fully recharge the power bank within 2-3 hours. The most noticeable thing about this power bank is that it uses a Lightning Input port, instead of the more commonly used Micro-USB Input port.

This means that iPhones users can simply use their Lightning charging cables to recharge the power bank and the Android users will have to own a Lightning cable to recharge it. It’s quite a rare case of a switcharoo.


The portability of it is is really good and it’s basically the size of a smartphone, if not smaller than one. It has a length of 4.9 inches, a width of 1.8 inches and a thickness of 0.5 inches. So the width and length are quite a lot shorter than other slim power banks, and the thickness is just a bit thicker than others.

With that said, the power bank can still fit into your pocket, although it’s best to just place it into a pocket alone and keep your smartphone separate at the thickness combined with the power bank and your smartphone can be quite uncomfortable.

Full Review for Aukey 3,600mAh Portable Charger

Specs of the Aukey 3,600mAh Portable Charger External Battery:

  • Capacity:            Advertised: 3,600mAh             Real Capacity: 3,000mAh
  • Output: 5V/1.5A
  • Input: 5V/1.0A Via Micro-USB Input
  • LED Power Indicators: Single Light Power Capacity Indicator

0%-20% : Red
20%-60% : Green
60%-100% : White

  • Size: 4.9 x 1.8 x 0.5 inches
  • Weight: 2.9 Ounces


At Charger Harbor, we heavily the value that Slim power banks are able to offer in the way of portable power. They can provide a much better portable experience with their flat designs and by doing so, they’re basically like owning a second smartphone.

The ability to place it into your pocket and have to smartphone charging while you’re walking or doing a task is something that needs to be more common. Making charging a passive habit should be a goal and that’s what Slim power banks are able to achieve.

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