Portable Power Series: uNu Enerpak Tube Universal Battery Pack Review

In this installation of the Portable Power series, we have a battery pack from uNu called the Enerpak Tube. The tube is advertised as a device where “portability and power collide.  Able to re-charge almost any smartphone up to 3x while still managing to remain light-weight and completely portable, the Enerpak Tube is the most dynamic battery yet.” Does it live up to its marketing? Read on to find out.


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The Enerpak Tube’s design is, as expected, tubular. Overall, it’s a cylindrical design, with a modified ellipse for the end faces. The Tube is 4″ long and 1.75″ at its widest (the narrower axis of the ellipse is a bit under 1″) and weighs in at 123 grams. My review sample is “Tiffany Blue” with white (maybe super-light grey) faces. I would consider this product both lightweight and portable as their marketing suggests.

The vast majority of functions are all contained on one face of the Tube. On that face are the LED flashlight, output USB port, and input MicroUSB port.  Right above that face on the main body is LED charge indicator. Along the side of the unit is the only dynamic part, a button to check charge level (with a single-press) and to activate the flashlight (with a double-press).


Admittedly, a battery pack doesn’t have to do much, all I need it to do is to charge my gadgets in a relatively short timeframe. In that regard, the Enerpak Tube is great. I can plug in any USB charging cable and happily go on with my day knowing that my device is charging. With its 5000 mAh battery, I can charge my iPhone a little over 3 times, or my iPad Mini (1st Gen.) once. Where things get murky are how the extras perform. The LED flashlight for instance, casts an adequately wide swath of light, although it doesn’t carry very far. If you’re planning on going for a night walk, get a standalone LED pocket flashlight, but in a pinch, the flashlight on the Enerpak Tube is great. I don’t think it was ever intended to replace a pocket flashlight, but I think that it is perfect for, say, trying to find your phone in the dark, or simply seeing the ports on the Tube itself.

One point of concern is the LED charging indicator. I was initially bit baffled by its functions. The manual states that while charging, the indicators will light up one at a time and that when all 4 are lit the Enerpak Tube is full. During my time with the Tube, I have noticed strobing and solid red, strobing and solid blue, and solid green. The manual also states that when discharging, solid red means 1-33% charge left, and confusingly blinking red is 75-100% charge remaining. and that the blue LED is 66-100% remaining and green LED is 33-66%. The actual function is the following: 

Flashing Red: Empty, Solid Red: Low, Green: 50%, Flashing Blue: Almost Full, Solid Blue: Full. NOTE: Flashing only happens when charging, solid colors happen either while charging or checking the  remaining charge.

There is some variation in the light sequence as well as an error in the manual, and uNu has reassured me they are looking into it. So, if you are confused about the lighting, there is your answer. 

Wrap Up

Overall I really enjoy the uNu Enerpak Tube.  It’s small, lightweight, portable, and includes a nifty flashlight. Over the last couple of weeks I have kept it in my work bag as my primary charging method, and I haven’t found a real fault yet. If you are looking for a battery pack, you would be hard-pressed to find a better battery pack (that isn’t some sketchy Shenzhen Special off of Amazon or Ebay).  The Enerpak Tube retails for $60 from uNu, or $30 from Amazon.

-Good Capacity
-Fair price (on Amazon)
-Odd LED charge indicator

Comments (3)

  1. Jane

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