Review: Viivant Slim Portable Power Bank

Viivant Slim Portable Power Bank











  • Very Small and Slim
  • Great Design
  • Fast Charging and Recharging Speeds


  • Loses 1,000mAh of Power Capacity
  • Can Heat Up Quite a Bit


Small slim power banks are a category of portable chargers that can be a very good alternative if you’re looking for a portable charger that isn’t just small but it’s also flat. If you’ve taken a read of our Jackery Air 6 Review, then you know what a slim power bank has to offer and why they’re so awesome to use. However, slim power banks are still just mini power banks that have been elongated.

Or are they?

This Viivant slim charger is actually very surprising with what it’s capable of and Charger Harbor is here to do a review on what this power bank is capable of. Read on to know why this flat charger may very well come on top in the best slim power bank category.

Anker PowerCore Slim Charger


Power Capacity:

As I said before, capacities of slim power banks are meant to be small because of their size and even though that’s the case with most slim power banks, it’s less prevalent here. The Viivant features a power capacity of 5,000mAh and it matches the capacity of Anker’s PowerCore Slim 5000 charger.

The Viivant actually does a good job with retaining its real power capacity and by that, we mean the power bank loses about 1,000mAh of power capacity and what you have left is about 4,000mAh of Output power capacity left to use. Considering its size, this kind of capacity is really good. This small power bank can charge nearly any smartphone to its full capacity. Some smartphones will leave the Viivant portable charger with more power capacity to spare in case you need to use it again. If you choose to, you can even charge a tablet with the charger but we recommend using the full 4,000mAh available capacity because tablets require a lot more power than smartphones.

Overall, as long the Viivant power bank is fully charged, it’s going to deliver plenty of power for everyday use and it will most likely leave more capacity to use later on in the day.

DevicesViivant Slim Portable Power Bank (Output Capacity = 4,000mAhPhone CapacityViivant Slim Portable Power Bank Left Over Capacity after One Charge

# of Full Charges for the Device
iPhone SE4,000mAh1,624mAh2,376mAh

2.4 Full Charges
iPhone 64,000mAh1,810mAh2,190mAh

2.2 Full Charges
iPhone 6 Plus4,000mAh2,915mAh1,085mAh

1.3 Full Charges
iPhone 6s4,000mAh1,715mAh2,285mAh

2.3 Full Charges
iPhone 6s Plus4,000mAh2,750mAh1,250mAh

1.4 Full Charges
Samsung Galaxy S64,000mAh2,550mAh1,450mAh

1.5 Full Charges
Samsung Galaxy S6 Edge4,000mAh2,600mAh1,400mAh

1.5 Full Charges
Samsung Galaxy S74,000mAh3,000mAh1,000mAh

1.3 Full Charges
Samsung Galaxy S7 Edge4,000mAh3,600mAh400mAh

1.1 Full Charges

Output Charging:

It Surprisingly has 2 Charging Ports

Moving onto the charging, the Viivant power bank has two charging Output ports. Yes, that’s right, this insanely slim and portable power bank has two charging output ports that allow you to charge two devices at the same time. One charging Output port has a charging speed of 5V/2.1A and the other Output port has a speed of 5V/1.0A. The logic here is that a tablet would be connected to the 2.1A port and smartphones would be connected to the 1.0A port; even though that logic is quite sound, the two ports should be used with smartphones. We say that because, with two charging ports, the power capacity is being split apart.

If you want to charge a tablet with this power bank, then take advantage of this entire power capacity. However, if you charge two smartphones at the same time, then both of them will most likely charge to their full capacities. A smartphone that is connected to the 5V/2.1A port will charge faster than the 5V/1.0A charging port because of higher Amperage. It’s actually amazing to see a power bank of this size and capacity still be able to have two charging ports and for one of the charging ports to have 2.1A charging speed. The usual case is for a power bank to just have a single port with 1A charging, but this slim power bank exceeds expectations.

Input Charging (Recharging):

Recharges fast Too

Recharging is done through a Micro-USB Input port that is able to recharge the power bank at 5V/2.0A. This is yet another amazing charging speed because slim power banks have slow recharging speeds but in this case, the recharge is rather fast. You can expect this power bank to be fully recharged if you’re using a wall charger that is capable of Outputting at 5V/2.0A or higher; this is because the output charging speed of the wall charger has to match the power bank’s input speed. Recharging the power bank at 2.0A charging will recharge it fully in about 3 hours and 30 minutes. If you’re using a wall charger that is rated at 5V/1.0A, then you can expect the power bank to be fully recharged within 4-5 hours.


Size and Weight

Basically the size of a Smartphone

The main attraction of this power bank is the design. It measures 5.4 inches in length, 2.6 inches in width and 0.3 inches in thickness. Its got a weight of 5 ounces. Overall the portable charger is nearly the same size as your smartphone, or maybe even smaller than your smartphone depending on what smartphone you have. It can easily fit into your pocket along with your smartphone, you can hold it in your hand, place it on a surface to charge a device or put it in nearly any bag. The power bank is almost like owning a second smartphone, expect it’s just a source of power.

Functional Components

You can find the all the functional parts of the Viivant Slim in the same general area. The two charging Output ports and the Micro-USB Input port are on a narrow side of the power bank. There are 4 LED power indicators on the long side of it and a power button right next to the power indicators. The power bank automatically starts charging when a device is connected to it and it stops recharging once that device is fully charged. However, the power bank can be turned on if for some reason it stays off when a device is connected to it.

Or you can even manually turn off the power bank when a device is connected to the charger. Ultimately, the charger can be very hands-off and the power button can only be used to check the power capacity if that’s all you really want to do with the power button.

Other than the functional features that I mentioned above, there’s absolutely nothing else on the power bank and as a result, the charger is very smooth throughout its entire body.

The power bank is able to conduct Pass-Through Charging but be please weary of using such a charging feature because if you read our write up on what is Pass-Through Charging is, then you’ll know that it can cause quite a lot damage to a power bank.

The Viivant slim power bank is able to offer an amazingly slim design that can go anywhere and is capable of some awesome features.

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Structure and Material

The entirety of the Viivant slim power bank is made of Aluminum. There’s a large center body and side caps that are both Aluminum. The side caps are placed very well and there are no signs of them parting ways from the main body. The center body harbors no opening or slits that may cause the body from cracking. The physical structure of the power bank is strong and holds tight.


Viivant hasn’t laid out any specifications pertaining to their safety tech but it can be quite clear on what they do have with this power bank. The slim power bank doesn’t heat up too much but there is still heat that can be felt while it charges. This is mostly because of the current passing through the device and into the device it’s charging. However, this heat generation leads to the Power problem that I mentioned earlier, which is the reduction of the power capacity. Viivant currently uses a Grade A Lithium Ion Polymer battery with this power bank and although Polymer does a good job at charging it does tend to lose a lot of capacity when charging is taking place.

The solution to this power capacity loss and to lessen the heat generation is to use Panasonic battery cells because this way, the power bank will have better conversion rate through its battery and less heat may be generated. Portable chargers that tend to use this are Jackery products like the Jackery Mini and Anker’s PowerCore 20100.

That might work, though. The Viivant slim power bank uses two charging ports, so it might be over-stepping its boundaries on what it should be capable of and what it’s actually capable of.

Similar Slim Power Bank


It’s slim, it’s got the power capacity, the charging capabilities and the design of a smartphone. The Viivant slim power bank has plenty of flaws that can make it less than what it actually is; even so, the portable charger is still more capable than what’s expected of it. Most slim power banks of its size are expected to just a have a single charging port that has a charging speed of 5V/1.0A and the same Input speed. Not only that, similar power banks are expected to have lower capacities, even lower than the real capacity of 4,000mAh that this Viivant power bank has.

When you get this slim power bank, you’re relying on more than what’s expected. Sure the power capacity is less than what it’s supposed to be and it can generate quite a lot of heat but everything else is able to exceed expectations.

The Output power capacity of 4,000mAh can charge your smartphone about two times. There are two charging ports that allow you to charge two devices at the same time.

You can actually charge a tablet and a smartphone at the same time.

Two tablets at the same time.

Two smartphones at the same time,

I think you get the idea that this power bank is very versatile when it comes to charging. The sizing allows you to take it anywhere, after all, it’s a slim power bank and this means that you can easily fit it into your pocket along with your smartphone to have your smartphone charge while you’re doing something else.

You can depend on this Viivant portable charger for nearly all situations, along with its ability to exceed what’s expected from it.

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The Viivant does nearly everything right, on the power side of things but the power capacity is missing a 1,000mAh of capacity. The power bank features two charging ports. One charging port charges at 5V/2.1A speed and the other charging port charges at 5V/1.0A  speed. The Input charging speed or better known as the recharge speed is 5V/2.0A and as a result, you can fully recharge the power bank in 3 hours.


Viivant has practically created a flawlessly designed slim power bank that does a great job at being super portable. It’s about the same time as your smartphone or maybe even smaller. All the functional portions of the power bank are few and out of the way. The charger can easily fit into your pocket along with your smartphone and is really lightweight at 5 ounces.


The build quality of the Viivant portable charger is nearly perfect when it comes to the physical structure of the power bank. However, Viivant hasn’t specified any safety tech, they promise that it has the necessary ones implemented. One main thing they should think about adding is a Panasonic battery because of its great conversion rate. They also need to work on heat generation, because the power bank can get quite hot.


When you use this power bank, you’re mostly relying on the things it ‘s done to surpass other slim power banks within its class. It does a great job of providing a lot of value within each category but the power capacity still needs to be perfected.

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


The Viivant super slim power bank is wonderful with the way it goes about providing plenty of charging options and power capacity. It does have its fault with missing quite a big chunk of power but even so the power capacity is still enough to charge most smartphones two times fully. The size and dimensions of the portable charger make it so that it’s very portable in nearly any situation and can fit into your pocket very easily. It’s basically like owning a second smartphone. Overall, if you’re searching for a slim power bank to buy, this one is not something you should put aside. It goes further than most slim chargers.

Comparable Slim Power Banks:


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