ReTrak 4000 mAh Power Bank - Black

  • Model #: ETESPB4
  • Web Code: 10450904
Sold and shipped by: Best Buy
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Keep your digital world powered up thanks to the ReTrak 4000mAh power bank. It delivers enough power to fully charge your smartphone twice and is equipped with a USB port so you can plug in any charging cable for any compatible device. Features a 5V/1A output and an LED light that lets you know when it's time to recharge the power bank.

More Information

  • Compact, pocket-sized power bank keeps your device charged while you're on the go
  • 4000mAh lithium-ion battery delivers 2 full charges for your smartphone and automatically turns off to conserve power
  • Standard USB port with 5V/1A output lets you easily plug in a charging cable for any device
  • Equipped with an LED light so it's easy to see when the power bank needs a recharge
  • Includes a retractable USB to micro USB charging cable

What's in the Box?

  • 4000mAh Lithium-ion Power Bank
  • Retractable Micro USB Charge Cable

Manufacturer's Warranty:

  • Parts - Lifetime
  • Charger Type
    Power Bank
  • Portable Charger Battery Type
  • Colour
  • Specific Device Compatibility
    Most smartphones and iPhones
  • Output Ports/Connectors
    1 x USB - Female; 1 x Micro-USB - Male
  • Input Voltage
    5 V
  • Output Voltage
    5 V
  • Output Power
    5 W
  • Output Current
    1000 mA
  • Total Cable Length
    0.30 m
  • Dimension
  • Width
    8.5 cm
  • Height
    16 cm
  • Depth
    3.5 cm
  • Weight
    129 g
  • Width (Inches)
    3.35 in
  • Height (Inches)
    6.30 in
  • Depth (Inches)
    1.38 in
  • What's in the Box
  • Warranty Parts



Customer Reviews

2.7 / 5
Based on 13 review(s) More about Customer Reviews

Ratings in Detail

  • 5
  • 4
  • 3
  • 2
  • 1

Positive vs. Critical Reviews

Positive 46%

6 Reviews

Critical 53%

7 Reviews

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  • from Red Deer

Turn phone off while charging

Bought this about little over 6 months ago it works great I have a Samsung smartphone and it will charge it 100% twice but phone has to be turned off or else it will only charge my phone till 30%

  • from Chestermere, AB

Worked great

We got two of these as a bonus gift when we got new cell phones. I charged one up and threw it in our backpack and used it when we were in Cuba. I felt this was safer than plugging new iphones into the plugs in the hotel room. It worked great and charged the phone to 100% in about twice the time it would have taken if I plugged the phone into a regular charger. I haven`t tried the other one yet but I will be taking these whenever we travel as they are handy and take up little space.

  • from Vaudreuil


After charging it for 5hours it cant even charge my phone half ways and i have an old phone at the moment tried ot pn my flip phone and its not even able to give me a full charge for that ! Cant get a refund!

  • from Vaudreuil


After 5h of chargi

  • from Winnipeg, MB

Does its' job

Blinking red light when powerbank is charging. Solid red light when it's fully charged. Blue light when it's being used to charge a device. Works well, good quality, purchased it on sale for myself and my 2 children.

  • from Toronto, ON


Bought this thing in August and it died in December.

  • from Nanaimo, BC

it does the job

I bought this item 6 months ago and it does the job. Other then it being confusing to know when it's fully charged, it does the job. The LED light is a tiny blimp on the body of the case and there is nothing anywhere in the packing that helps you understand. It usual takes a good full 6-8 hours to make the red blinking light turn steady red, which I assumed was fully charged. It would give my phone, a Sony Z3, a 2x charge however, now I can only get x1 full charge out of it. I did use it heavily and used it as my battery power while using my phone (Pokemon) and it used to charge my phone while playing and now it just holds my battery charge around the percent I was at when I plug it in. I loved the retractable charger cable, so neat! I've gone out and bought a few more because of it.

  • from Richmond Hill, ON


Great value for price. Even better when you get it on sale. Charged my phone four times on one charge. Be sure to read instructions to know when fully charged. Red light stops blinking when fully charged.

  • from Washington

It sucks

Doesn't charge, never gets battery and won't charge your device

  • from Vancouver, BC

Horrible - useless.

Takes forever to charge up - the instructions don't tell you if the LED light is supposed to be green when fully charged - it never stopped being red, no matter how long I charged it. Couldn't even get 1 full charge for my iPhone 6.

  • from VICTORIA

Works... but there's a catch.

This item works fine, however it is NOT 4000 mAh as claimed. More like 1500mAh at best. Also the included USB cable did not charge my Galaxy S6, I had to use a different USB cable. Save your money and get a better power bank.

  • from Markham, ON

BAD Quality

The cable that is included in the kit is absolutely garbage. First the micro usb connector is larger than average and I need to take off my phone protector to make it fit. Second when I used the cable to charge my phone from my laptop it drains my phone's battery instead of charging it. I would stay away.

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