Review: Re-Fuel by Digipower Grab-n-Go 4200 mAh Battery Pack


Review: Re-Fuel by Digipower Grab-n-Go 4200 mAh Battery Pack

I love a good product, and when I find one, I like to tell folks about it. This Re-Fuel battery pack is one of those products. It’s a compact, portable, light, long-lasting battery pack that can keep your smart phone or other portable electronic device alive when you’re on the go or far from an electrical outlet.

Some of the first things I noticed about the Re-Fuel Grab-n-Go 4200 were the compact size, sleek look, and light weight. And with that came doubts about its strength. After all, how long could a small, light battery pack last? Those doubts were quickly erased when I began using it.

The Re-Fuel arrived during turkey season, which was good. While hunting, I use my smart phone (currently an old iPhone 4S) to keep notes, and I confess that I’ve been known to fill empty hours with sudoku, word games, or Angry Birds. And the older this phone gets, the wimpier the battery is. In order to get any real use out of my old phone, I have to use an external battery of some sort to keep it going.

(Photo: Mizco Corporation)
(Photo: Mizco Corporation)

What it is

The Re-Fuel Grab-n-Go 4200 is black and chrome and is just 4-3/4″ long, 1-5/8″ wide, and a little more than 1/2″ thick–and it weighs a mere 3.6 ounces. All corners and edges are rounded and it has a nice smooth finish, so it slides easily in and out of your pocket. Capacity is 4200mAh, 15.54Wh. Input is 5 volts at 1 amp, while output is 5 volts at 2.1 amp, and it’s made in China.

(Photo: Mizco Corporation)
(Photo: Mizco Corporation)

This battery pack is charged via a Micro USB port. For output, you can either plug in a standard USB cable or use the short (about 3.5 inches) built-in Micro USB cable. A white-and-silver version is also available with a short Lightning cable instead of Micro USB.

A series of four tiny blue LEDs in the silver portion of the housing indicate the Re-Fuel’s charge level.

It’s easy to use: Simply connect it to something you wish to charge, then press the power button once. Done! To charge the Re-Fuel, connect a Micro USB cable to the “in” port and press the power button. The blue lights will indicate charge status. When all four of them shine constantly, the Re-Fuel is fully charged.

Don’t worry about turning it off; it will turn itself off whenever there’s nothing being charged.

Starting Out

When I opened the package, I was glad to see that the battery seemed fully charged. This confirms the product description, which says it “comes pre-charged and ready to use right out of the box.” They ain’t lying.

Two days later, I was in the turkey hunting woods and at 8:06 my phone was at 43% and falling. I plugged it into the Re-Fuel pack and by 9:04 the phone was up to 89%; 92% when I got up to move at 9:25. The next time I checked was 9:47, and the phone was at 100% and the Re-Fuel still showed all 4 lights.

After disconnecting the Re-Fuel (10:13), my phone again dropped rapidly (82% at 10:24). By 10:38 I had to plug in again at 63%, and by 11:40 the phone was at 95% and the Re-Fuel was down to 3 lights.

The Re-Fuel is small enough and light enough that it can easily sit in a shirt pocket with a cord run to my phone, and I usually don’t notice that it’s there.

Over the next few days of hunting, I had similar experiences–and I didn’t charge the Re-Fuel at all during that time. It’s quite impressive, and is the most effective battery pack of small size that I have ever used. It charges my phone well and lasts through a number of charges.

You can expect, of course, that devices with larger batteries than my old 4S will require more of the Re-Fuel’s capacity, but as long as 5v at 2.1A will charge them, I believe the Re-Fuel will do the job for you.

Charging it

I had some trouble the first time I charged the Re-Fuel, probably because I was over-complicating things. I charged it again a few days ago, and it was pretty easy. Just plug it in and wait a few seconds. If you don’t see any blue lights on the face of the Re-Fuel, press and release the power button one time. When charging, one of the blue lights will always be flashing until it’s full, then all 4 LEDs will be illuminated.

It does take quite a while to charge, which makes sense considering its high capacity. Charging it overnight is probably your best bet.


I have written hundreds of reviews over the years, and most of the time I’ve included both pros and cons. In this case, the only con I can come up with is that it’s not waterproof.

I realize that nothing is waterproof when you plug into it, but some battery banks have port covers to keep dirt and water out when you’re just carrying it in pocket or pack. With this Re-Fuel, I’ll probably just slip it into a small Ziploc bag and rock on.

As I said, that’s the only downside I found, and I’m known to be pretty critical.

I think it would be hard to go wrong with the Re-Fuel Grab-n-Go 4200.

Manufacturer Specs

  • Battery comes pre-charged and ready to use right out of the box.
  • 1 amp of power from the micro USB cable for Smartphone charging, up to 2.1A of power from the USB port for tablet charging.
  • Portable design fits comfortably in your pocket or bag.
  • Provides up to two full charges.
  • Power Protection circuitry to safeguard your devices from over voltage, over current and short circuit.
  • LED charge indicator
  • 1-year warranty
  • Dimensions (inches): 4.75 x 1.65 x 0.65
  • Capacity: 4200mAh, 15.54Wh
  • Input: 5V/1A
  • Output: 5V/2.1A Max
  • Model: JS-450M-BK
  • MSRP: $49.99
  • Product Page


Avatar Author ID 61 - 1204349781

Editor & Contributing Writer Russ Chastain is a lifelong hunter and shooter who has spent his life learning about hunting, shooting, guns, ammunition, gunsmithing, reloading, and bullet casting. He started toting his own gun in the woods at age nine and he's pursued deer with rifles since 1982, so his hunting knowledge has been growing for more than three and a half decades. His desire and ability to share this knowledge with others has also grown, and Russ has been professionally writing and editing original hunting & shooting content since 1998. Russ Chastain has a passion for sharing accurate, honest, interesting hunting & shooting knowledge and stories with people of all skill levels.

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