Milwaukee RedLithium USB Flashlight

Milwaukee RedLithium USB Flashlight
PTR Review
  • Pro Review 8.7

Getting onboard USB charging, beam focus, and IP67 protection for a metal LED flashlight for just $69 makes Milwaukee's RedLithium USB Flashlight one of the best values available.

Overall Score 8.7 (out of 10)

The Milwaukee RedLithium USB Flashlight is part of a new series of personal lighting solutions that’s off Milwaukee’s typical path. What’s different is that they run on a single 4V lithium-ion cell rather than the M12 or M18 battery packs. That makes them much less bulky and easy to carry in a tool bag.


The line is most compelling as a group. The combination of flashlight, headlamp, and flood light with reasonably compact sizes means you can carry lighting solutions for nearly every situation and keep all them in your bag all the time.

Obviously, this doesn’t include high output work lights to cover a large area for the whole crew, but you’ll be able to stay productive nearly anywhere.

Milwaukee Redlithium USB Flashlight Construction

The flashlight in the series follows the Milwaukee M12 Metal LED Flashlight – a full-size flashlight with excellent build and light quality. You’ll see similar features on a smaller scale with this model.

The most obvious is the metal construction. Nearly every flashlight I carry for jobsite and recreational outdoor use share this thanks to the toughness it brings. Anything else is relegated to the gift pile for birthdays and Christmas.

Clip In

The belt clip is very knife-esque in its design. You’ll find a similar, though smaller, design on Milwaukee’s Hardline folding knives. It appears to be removable, but in practice, it really doesn’t want to go anywhere. I like having it there, though the strength is on the weaker side for the size. So if you do bend it out (that’s nearly a guarantee for me), you’ll have a hard time bending it back.

Milwaukee RedLithium USB Flashlight

USB Charging

Like all the lights in the RedLithium USB series, there’s an onboard charging port. This one actually takes some work to find and open, at least at first. Give the base of the light an upward twist to reveal the micro USB port. It’s a cool design that hides the charging port with an o-ring for protection. The design fits tight, though, so you’ll have to work it pretty hard to get it open the first time. It’s easier after that, but it will still stick some.

Milwaukee RedLithium USB Flashlight

Battery Access

To access the battery to swap it out or put it in the standalone charger, unscrew the base cap like you do on most flashlights. The battery has more of a friction fit than the headlamp that simply falls out. This one fits much tighter. A recessed slot on either side helps give your fingers a grip around the battery to pull it out.

Milwaukee RedLithium USB Flashlight

The battery doesn’t have positive and negative connections on the top and bottom – they’re on the side. You’ll need to ensure that you seat the battery perfectly. There are indicator arrows to help you center it and you can just rotate the battery until it slips into position. You won’t be able to reinsert the housing until it’s set correctly. It all sounds more complex than it really is. After you do it once, you won’t have to think about it again.

Milwaukee RedLithium USB Flashlight

Maintain Control

The Milwaukee Redlithium USB Flashlight has three modes – high, low, and strobe. High will give you 700 lumens, which is pretty solid for this size light. I have others that go as high as 1000, but they’re designed purely for outdoor and tactical use and are much more limited on runtime. Low will give you 100 lumens and is a really good level for close-up inspection. While the flood light or headlamp are probably better options, you can set the beam to flood and the belt clip will keep the light from rolling away if you need it as a work light. Strobe, of course, is good for signaling or as a non-lethal defense tool.

The power button to control the modes is on the base where it’s easy to access with your thumb. A half click will allow you to cycle through the modes, making it a little more convenient to find the one you want to work with before clicking it fully on. Of course, you can also just cycle with full clicks.

Milwaukee RedLithium USB Flashlight

There’s a slide focus for the lens to move between spot and flood beams. I personally prefer a twist focus since it helps me dial in the exact amount of flood/spot combination I’m looking for. Realistically, though, I usually end up in full spot or flood and not in between.

Light Quality

Milwaukee uses their TrueView 5000 K LED in this light, but it’s not as obvious as it is on the large work lights. The side of the beam is warmer toned than the center, so it’s tough to see the neutral color with a spot beam. It becomes more viable when you slide the focus to flood, where the center casts a more neutral throw and the warm tones move to the corona.

There’s a diffuser on the lens that helps soften the light a bit. Compared to my non-diffused lights, this may hurt the throw distance some, but it makes using the light for a work area easier on my eyes.

The Bottom Line

I really like the overall design of the Milwaukee RedLithium USB Flashlight. The focusing beam, solid output, and size are all major pluses along with onboard recharging and easy battery changes when needed.

My big suggestion for improvement is in the belt clip. I’d strengthen it and ensure it’s easily removable when you twist the back cap off. That will ensure you can bend it back in place when the inevitable happens.

As for minor improvements, I’d just like to see the focus be a twist motion rather than a push/pull and find a way to keep that charging port from sticking quite so much. I like the hidden design, though, so I would rather deal with the stick than see it moved to the exterior.

At $69, this light is priced well in its category of medium size rechargeable flashlights. Getting a rechargeable, adjustable focus light in this output range from Coast or LEDLenser will set you back well over $100. While you might be tempted to look at other options out there, it becomes a very compelling solution when considering it as part of a system of personal lighting with the headlamp and flood light along with a limited lifetime warranty.

Milwaukee RedLithium USB Flashlight Specifications

  • Model: Milwaukee 2110-21
  • Power Source: RedLithium USB 4V battery
  • Output: 700/100 lumens
  • Stated Runtime: 16 hours (low), 4.5 hours (high)
  • Modes: High/Low/Strobe
  • IP Rating: IP67
  • Length: 6.65 inches
  • Weight: 0.50 lbs w/battery
  • Price: $46.49
  • Warranty: Limited Lifetime

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