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Reviews > Electronic Devices > Chargers > Brunton Revolt 4000 USB > Test Report by jerry adams


INITIAL REPORT - March 11, 2015
FIELD REPORT - May 29, 2015
LONG TERM REPORT - July 18, 2015


NAME: Jerry Adams
EMAIL: jerryaadamsatyahoodotcom
AGE: 61
LOCATION: Portland, Oregon, USA
HEIGHT: 6' 1" (1.85 m)
WEIGHT: 195 lb (88.50 kg)

I started hiking about 45 years ago. My first backpack was 40 years ago. I currently try to do one backpack trip of 1 to 5 nights every month (which can be tricky in the winter). Mostly I stay in the Western half of Oregon and Washington. In recent years I have shifted to lightweight - my pack weight without food and water is about 12 lb (6 kg). I make a lot of my own gear - silnylon tarp-tent, bivy, synthetic bag, simple bag style pack.



Manufacturer: Brunton
Year of Manufacture: 2015
Manufacturer's Website:
MSRP: US$49.99
Listed Weight: 4.9 oz (139 g)
Measured Weight: 5.8 oz (164 g)
Listed size: 3 x 3 x 1.3 in ( 7.6 x 7.6 x 3.3 cm)
Measured size: 3 x 3 x 1.2 in (7.6 x 7.6 x 2.7 cm)
Other details:

The Brunton Revolt 4000 is a USB power bank. It can be used to charge electronic devices that use a USB connector for charging. It has a 4000 mAh Lithium Polymer battery.

On the package, it says it's "optimized for hand-held electronics like phones, tablets, GPS, and UV water purifiers". I don't have any of those, but I have a camera and an AA NiMh battery charger that require a similar amount of charge. I also have an MP3 player that I'll test, but it requires a very small charge which the Revolt is over-kill for. I always charge my camera before a trip and it never runs out of power, so this will be an artificial use just to test the Revolt.

The Revolt has a little door on the side that opens up. There are two connectors inside:


The top connector is a micro USB input for charging the Revolt. The bottom connector is a standard USB output for charging devices.

There's a button on the top that can be pushed. There are 5 battery level indicator LEDs that can turn on. They all turn on if the Revolt is fully charged. None of them turn on if it's fully discharged. If it's partially charged, 1 to 4 of the LEDs turn on depending on how charged it is. The LED lights also turn on when something is plugged into either of the connectors.

The Revolt comes with a 3-in-1 cable:


It weighs 0.5 oz (14 g). It has a standard USB connector on one end, and three types of connectors on the other end, including a micro USB. To charge the Revolt, the micro USB is plugged into the Revolt (as shown in figure above) and the standard USB is plugged into a power source such as a computer, a wall USB power source, or a car USB power source. I think the other two connectors are for some type of Apple products. I won't be using those. After the test is complete, I might just cut those off to save some weight.

The 3-in-1 cable can also be used to charge devices. Plug the standard USB connector into the bottom connector on the Revolt, and connect any or all of the 3 plugs on the 3-in-1 into devices that need to be charged.

Here's the Revolt, upside down, with a USB power meter and the AA NiMh charger plugged into it:


There's some product info - input 5V 1A, output 5V 2.1A, made in China.

I'll use the USB power meter to check the Revolt. It plugs into the Revolt, and then a USB device plugs into the USB power meter, and the power meter displays the voltage and current going to the device. I can verify the Revolt specs and so forth.

The Revolt is covered with a stiff foam material that absorbs shock. The Revolt is advertised to be weatherproof and shockproof. The door has a gasket material that seals the connectors from the weather to provide weatherproofness.

The battery is a Lithium Polymer battery.

The Revolt comes in 5 colors. I have the black.

Here's the Revolt charging my MP3 player:



I really like the Revolt.

All the seams are even. The connector door opens and closes good. The button on top has a good feel. The foam on the outside seems designed well - it projects out from all corners and edges. It feels really solid.

I have some cheap shit Chinese electronic devices including a USB power bank. The Revolt seems much more solidly built.

The Revolt came fully charged (that is, all 5 LED lights came on indicating fully charged). I charged up my camera successfully.

I successfully charged the Revolt from a wall USB power source.

Okay, I had to do it, I plugged the 3-in-1 cable micro USB into the Revolt, and also the standard USB into the Revolt. That is, I tried to charge the Revolt from itself. Nothing happened. No lights turned on.

I also tried using the Revolt while being charged. There was no output. So, the Revolt cannot be used while it's being charged. Not that there would be a reason for doing this.

Minor nit - the top button is not recessed inside the stiff foam, so if I hit the top of the Revolt it might damage the button.

Another minor nit - the standard USB connector is upside down. The seam on a standard USB connector is supposed to go down, but it goes up for the Revolt. When I plugged in a standard USB connector what I thought was right side up, but for the Revolt was upside down, I was able to do so but nothing happened, so I unplugged and plugged it in upside down, which is right side up for the Revolt, and then it worked. There's no damage from plugging it in wrong.

I am looking forward to testing this.


The Brunton Revolt 4000 is a USB power bank. It has a 4000 mAh Lithium Polymer battery, which is advertised to provide "2.5 smart phone charges".

It seems really well built. It feels solid.

It's nice that it's weatherproof and shockproof, although probably not really needed for a USB power bank. Charging is done in a protected environment. Devices like cameras and GPS are what need to be weatherproof and shockproof. I might rip off the cover when I'm all done testing to save some weight.

I'll test it on several backpack trips during the Field Report and Long Term Report periods. I'll also do some testing on my patio to verify capacity etc.



I did some testing on my patio which was about 60 F (15 C). I used my USB power meter which measures and displays the voltage and current. I first charged and then discharged the Revolt under a constant load, a USB fan.

Testing with the fan. You can see the USB power meter:

Next, I discharged the Revolt with several other loads (at room temperature):
- Kindle Fire - 1.65 A - 1.5 hours - 2500 mAh - this charged the Kindle about 3/4
- Point and Shoot camera - 0.47 A - charged it completely which used only a portion of the Revolt
- small MP3 player - 0.09 A - the Revolt kept turning off, maybe because the Revolt "thought" there was nothing connected so it just turned off
- big MP3 player - 0.33 A - completely charged about 2.5 times (7.5 hours) - 2500 mAh
- AA NiMh charger - 0.14 A - 13.5 hours - 1900 mAh
- AA NiMh charger in the refrigerator where it was 38 F (4 C) - 13 hours - only slightly less

I charged the Revolt with several chargers:
- 1 A wall charger (4 hours to charge)
- 500 mA wall charger (8 hours to charge)
- a small USB power bank (just partially charged Revolt to see if it would work with small charger)

I tried the 3 in 1 cable provided by Brunton, and several other cables.

Then I did some field testing:

April 1, 2015 - I did a 44 mile (71 km) 4 night backpack on Badger Creek near Mount Hood in north central Oregon. 28 to 50 F (-2 to 10 C). 3000 feet (900 m) elevation. I charged 4 AA batteries for my radio and GPS. I could not get my small MP3 to charge at all. When I got home and put my USB power meter in between MP3 and Revolt, it charged without problem.

Charging my GPS batteries on Badger Creek:

April 17, 2015 - I did a 33 mile (53 km) 2 night backpack to Enchanted Valley in Olympics in northwest Washington. 40 to 65 F (4 to 18 C). 1800 feet (500 m) elevation. With the USB power meter I could charge my small MP3 for a while, but then the Revolt turned off when the MP3 was only half charged. I also charged 4 AA batteries from my radio and GPS.

May 20, 2015 - 42 mile (68 km) 4 night backpack on Zigzag Ridge on Mount Hood in north central Oregon. 40 to 65 F (4 to 18 C). 4500 to 5500 feet (1400 to 1700 m) elevation. I charged my large MP3 three times.


Overall, I was satisfied with the Brunton Revolt USB power bank.

The Revolt successfully charged a number of devices:
- Kindle Fire E reader
- point and shoot camera
- NiMh battery charger
- big MP3 player
- small MP3 player

The user specs say the Revolt will charge an E Reader 1 time. It only charged my Kindle about 3/4.

The five LEDs on the Revolt are approximately linear. When the first LED blinks, the Revolt has 0 to 20% capacity, 2nd LED - 20 to 40%, etc. When the Revolt is charging a device, and the Revolt is almost discharged, the first LED blinks more quickly to let me know it only has a little left.

While I was charging a device, the Revolt did not get significantly warm, but the device being charged did get warm.

I measured the capacity of the Revolt at 2500 mAh. They spec it to have a Lithium battery of 4000 mAh, but that's at 3.7 volts which has to be stepped up to 5 volts for USB, so the capacity would scale down to 2900 mAh. My 2500 mAh is 86% of this, which is due to inefficiency of the device or under capacity of the battery. I think this is typical of USB power supplies.

The Revolt automatically turns off if there's nothing plugged in, to preserve power. For some reason, the Revolt shuts down when charging my small MP3 player - maybe the current is so low the Revolt thinks there's nothing there. If I plug the MP3 player into my USB power meter and plug that into the Revolt, it works better - the power meter must draw a little extra current.

When I plug in some USB cables to the Revolt, it automatically turns on. For other cables, I have to push the button on the Revolt to turn it on. I think this is because some cables/devices have a resistor between the data and power lines to communicate to the device how much current it wants (or something).

When I plugged in my AA charger, the Revolt never turned on at all, even if I pushed the button on the Revolt. If I first plugged in some other device, or just the 3 in 1 cable, then quickly plugged in the AA charger, the Revolt worked fine.

I think this is all typical of USB power sources and the fact that the USB as a charging interface was an afterthought. I make sure to use the exact combination of cable(s) and device(s) I'll be using, before going on a trip and finding out it won't work.

I charged the Revolt with a number of power sources. For a higher capacity power source, it didn't take as long. The Revolt worked on every power source I tried. I have heard, some devices require a certain amount of current, and if the USB power source can't deliver, it just shuts down. The Revolt charged on even low capacity power sources. With a 1 amp wall charger (that actually delivered 1.2 amps) it took 3 hours to charge 90%, then another hour to charge the rest of the way. For the first 20%, the first LED blinked. For the next 20% the first LED was on and the second LED blinked. etc. When it was fully charged, all the LEDs were on all the time. It got a little warm when charging.

The case of the Revolt seems really robust and waterproof, although I didn't really test this. If anything, it seems overly robust which results in extra weight. A charger doesn't need to be robust because I use it in my tent, protected, at the end of the day.

The Revolt worked without problem on my three backpack trips.


Overall, I was satisfied with the Revolt.

It successfully charged a number of devices.

The capacity of the Revolt was as expected, about 86% efficient.

I successfully charged the Revolt from a number of power sources. The Revolt charged faster with a higher capacity power source, and slower with a lower capacity power source.

The only problem was some combinations of cables and devices would not work. I think this is a consequence of the fact the USB interface wasn't really designed for charging.

An annoyance is that the USB connector on the Revolt is upside down. Until I learned this, I kept trying to plug in cables upside down. And, my USB power meter reads on the opposite side as the Revolt charge indicator LEDs.



June 20, 2015 - I charged my MP3 player at the trailhead after backpacking in the Three Sisters in central Oregon. 70 F (21 C), 5000 feet (1500 m) elevation.


I only used the Brunton a little bit during the Long Term Test period. After a backpack trip I used it to charge my new MP3/radio a couple times until the Brunton was discharged. The Brunton worked fine.

I got a new MP3/radio that has a 900 mAh battery. The Revolt only has enough capacity to charge it two times which isn't enough for a backpack trip.


The Brunton Revolt was just what I expected - it successfully charged a number of devices that have a USB interface.

It looks and works like new after my testing.

One problem is, like I said in the Field Report period, it was weird for some devices:
- My little MP3 drew so little current that the Revolt didn't know it was there so it just shuts off
- The Revolt didn't recognize my AA battery charger until I first plugged in another cable, then quickly unplugged it and plugged in the AA charger.

The Revolt is a little heavy for the capacity, but I think that's because of the shock and water proofing.

In the future, I'll carry the Revolt in my car so I can use it to charge when I get back from a hike. For backpacking I feel the Brunton is too heavy for the charging capacity it offers. Personally, Id rather have something lighter, even if its less water/shock proof.

Thanks to Brunton and for letting me test this.

This report was created with the Report Writer Version 1.5 Copyright 2015. All rights reserved.
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