[Review] Klarus G15 (4000 Lumen EDC Flood, 21700, Cree XHP 70.2)

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[Review] Klarus G15 (4000 Lumen EDC Flood, 21700, Cree XHP 70.2)

Welcome to 2020 and for my first review of the year I have the new Klarus G15 a small form factor 21700 EDC style light capable of upto 4000 lumens on Turbo from it’s Cree XHP 70.2 LED. Thanks to Klarus for sending me this early sample for review and evaluation.

Youtube Version of this Review:

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Packaging and Accessories
Packaging here is a nice high quality cardboard box with a picture of the light in front being part of the model number G15. The sides list the battery, capacity, and charging speed, and a highlight of the specs, including the 5 year warranty. On the back you have a more detailed spec chart and list of features. The light is IPX 8 water rated.

Included accessories are the Light itself, Klarus Branded 5000mAh button top protected 21700 battery. It’s listed as a 15A capable battery. The battery itself is long coming in at 74.7mm. Also included is a spare oring, Klarus branded lanyard, Felt pouch, manual and MicroUSB charging cable.

The light is made from aluminum and anodized a smooth fairly glossy black. The tail is flat allowing for the light to tail stand, but it’s non magnetic. The tail has been cut on the side to allow for the lanyard to attach. The body and tail are all one piece, with the long clip only attaching on the rear section. It allows for deep carry and it’s fairly stiff. The milling on the body tube to provide texture looks like the profile for an involute gear and then has 6 flats milled into the light. I like the pattern here, it’s a little different, provides good grip without being too aggressive. The flashlight only disconnects between the head and the body. The threads are raw aluminum, and beefy square cut with grease.

The head features the same button we saw on ST15R and XT21X in 2019. It’s a silicone button with an illuminated sliver of light around it that indicates battery status and goes Green/Red/Yellow. There is minimal milling on the sides for heat dissipation. Opposite the button is the flush fitting silicone port to protect the MicroUSB charging port. It’s at a standard depth and there is plenty of clearance for larger cables to fit. The head has minimal branding and labels on it, and light bronze color. The front bezel is smooth, and it looks like it will unscrew with the right tool. The lens is anti reflective coated glass, surrounded by a deep orange peel reflector with the large XHP70.2 LED at the center.

Size & Weight
I measured overall length of the Klarus G15 at 122mm, maximum diameter in the head at 27.5mm between the button and the charging port, and minimum diameter on the body at 23.24 between flats. Weight with the included battery and clip is 142.1g.

Looking through my light collection I don’t have a ton of 21700 sized lights that are super comparable here. Lights that I have that are similar are most often using an 18650 or end up being larger. I settled on comparing it to the Olight M2R Pro since they use the same battery and are physically similar. The Olight is a bit longer here, and heavier and is more tactical in nature. It’s also more of a thrower where the G15 is more about flood.

LED | Beamshot | Runtime
The Klarus G15 is using the Cree XHP 70.2 LED in a cool white 6500k tint. Being a 70.2 LED there is tint shift across the beam but it’s not as dramatic as I have seen from a few other lights. There is a slight increase in intensity in the center but this is more of a flood style light then a thrower. The spill is very wide and fades into nothing without a cutoff.

Mode Spacing here as you can see in the table below is ok but could be improved. There is quite a bit of difference to the eye between medium at 500 lumens and high at 2000 lumens. An additional mode in between would be nice. That said to the eye here is a difference between high at 2000 lumens and Turbo at 4000 but it’s not nearly as much as you might think.

My runtime’s didn’t match Klarus’s all that well. For my first runtime test I started the light on Turbo uncooled and the light steps down pretty aggressively quite quickly about 4 minutes before starting a seasaw motion as the light heated up, and them stepped down to cool off but then what was nice is that it went brighter again as thermals and battery power allowed. The average output for the first hour was somewhere around 60% relative output. The next hour was very stable at about 45% output, before the light started to step down slowly and small bumps at first before LVP kicked in at about 185 minutes of total runtime. Other major manufactures, namely Olight have started to be very honest about what their high lumen lights can do before stepdown and I belive Klarus should do this as well, it would be more honest then to suggest their lights can do 1.2 hours on turbo or 1.5 hours on high. Reality is no light can do this but it’s not obvious to non flashaholics.

Overall heat was well managed with the active thermal controls here. At 1 minute I measured 92F, at 2 minutes at 98F, and at 10 minutes I measured 96F. LVP kicked in at 2.688v which is lower then I would like to see.

UI here is simple and straightforward and it has 8 total output modes. 5 of those modes are constant on, and 3 are forms of blinking. From off, long press on the button to get to moonlight mode at 1 lumen. Press again and hold to get to low, keep pressing to cycle through low, medium and high. Double click to go to turbo. Tripple click to go to the blinking modes.

The light also features memory mode for modes other then turbo, moonlight, or the storbes. It also had lockout mode, but I personally just break contact with the battery as it’s easier and faster.

The light recharges with a standard MicroUSB cable, this is a little frustrating given the price of the light and that it’s a new release for 2020 where USB-C should be the standard. I recharged the included 5000mAh battery from LVP at 2.825V to Full at 4.13v in 3 hours and 35 minutes with a maximum charging speed of 1.99A. As the battery capacity filled up charging slowed down as expected. I saw no problems with the built in recharging on this light.


  • Compact size for a 21700, nice fit and finish
  • I enjoy the new gear tooth milling in the body
  • Easy interface
  • Active thermal controls.


  • MicroUSB instead of USB-C, at least the charging speed here is fast at 2A
  • Pretty cool LED tint with some of the characteristic XPH 70.2 tint shift across the beam

If you are looking for a compact 21700 style EDC flood light with an electronic switch up front, the G15 could be a good choice for you. It was a surprise to see active thermal management here that allowed the light to get brighter again after step down after it cooled off. Not enough lights do this in my opinion. I like the new texture here on the body of the light, hopefully it’s something that stays, I think it’s just about perfect for EDC, not too much to rip up your hand or pocket but definitely better than standard diamond knurling. 4000 Lumen turbo mode here isn’t quite as impressive as the numbers suggest, it’s not significantly different from the high of 2000 lumens. That said it’s really a light that’s best run on the lower output modes anyways for a more useful runtime. Hopefully in 2020 we see Klarus switching to USB-C (That support USB-C to C) in their higher priced lights and we can be hopeful that we will see something other then cool white too for us enthusiasts like myself that prefer warmer and neutral tints. With all that said I can recommend the Klarus G15 with reservations.

Full Image Gallery on this review https://imgur.com/a/9b3UVcV

Last seen: 4 hours 54 min ago
Joined: 07/13/2019 - 17:13
Posts: 121
Location: Germany

Nice review, thanks. I agree with you on the level spacing, it's terrible. Something like 1-10-100-1000-4000 would have been much more useful. 

Last seen: 1 year 8 months ago
Joined: 09/18/2019 - 16:27
Posts: 3

I’ve had this light myself since about December. Great light. I do hate the micro usb. Stop using micro anymore PLEASE. I would have also likeD a magnet in the tail as there is no button there. I managed to gorilla glue an N25 neo magnet to the back. 25mm is the magic size fyi. Works perfectly.

I love the deep clip. Not too heavy and relatively small given the power source but that’s a side clicky light for you, always less length than tail clicky and is a trade off I am willing to make to have a more compact light even though I prefer tail clicky. But in 21700, I am more ok with sidswitch than 18650.

I also HATE how to lock it out. You have to hold the button for what seems like FOREVER. I like how to unlock it, it’s quick and painless when I use the light at work but locking it out UUUUUUUUUUGH

ABSOLUTELY LOVE THE LED setup in this as well. I love the pure flood. 4k lumens this is giving me D4 lumens with a single led and deeper carry. I love my emisar D4 but I love having a 21700 power source giving me emisar D4 lumens Big Smile all of the run time without the 26650 size!

*Oh and I agree on turbo vs high lumens. Yea might not be 4k lumens but I still love the flood for a single led. And smooth white color with no yoke. I don’t notice much of a color shift.

"Failure to plan on your part, does not constitute an emergency on mine" - unknown
"Me and the boys would have started dropping bodies by now" - George Washington... probably.
"Acquire ALL of the lumens" - Abraham Lincoln... most definitely

Last seen: 1 hour 48 min ago
Joined: 12/10/2017 - 12:46
Posts: 4339
Location: US

Thanks for the review! The light does look good and very compact like an 18650 light. Output is good but you get the typical XHP50.2 corona and tint shift. Here are my measurements using the Texas Ace lumen tube and Sekonic C-800-U. Output measured at 2 seconds.

Turbo 4052 lumens 6062K DUV -0.0016 CRI 75.4   R9 -8 R12 47.4 Rf 71 Rg 96
Top of Ramp 2138 lumens 5813K DUV 0.0008 CRI 74.7   R9 -14.2 R12 44.1 Rf 71 Rg 96
2nd highest 528 lumens 5740K DUV 0.0029 CRI 75.3   R9 -16.3 R12 42.1 Rf 72 Rg 94

It's the brightest single cell rechargeable XHP70.2 I've tested yet but it starts to ramp down at about 5-7seconds, which is reasonable given the small mass. Nice to know Klarus is honest with their measurements. I just wish it had USB-C instead of micro USB. There is a separate ground wire next to the mcpcb. Not sure what that is for. Voltage across the + and - leads is about 6V.

Last seen: 1 year 8 months ago
Joined: 09/18/2019 - 16:27
Posts: 3

Awesome! So glad it’s 4k. Yes sad about the quick ramp down but I came to the same conclusion after how long my acebeam copper tk16 takes to ramp down vs the aluminum version; MUCH LONGER. Mass makes sense.

Overall I carry this light almost everyday at work. The added magnet is a nice touch too now.

"Failure to plan on your part, does not constitute an emergency on mine" - unknown
"Me and the boys would have started dropping bodies by now" - George Washington... probably.
"Acquire ALL of the lumens" - Abraham Lincoln... most definitely

Last seen: 8 months 4 days ago
Joined: 03/23/2018 - 06:05
Posts: 7

I was a bit suspicious of the stated runtime of 200h in Moonlight mode, which is a bit low for 1 lumen, so I measured the current draw which is 7 mA, so that’s more like 700h runtime, not sure why they said 200h.