Nitecore i4000R Intelligent Tactical Flashlight


Another Nitecore tactical flashlight coming at you. The one I’m reviewing today has an extremely impressive output and impressive features making it one interesting light. So let’s get started and take a look at the Nitecore i4000R rechargeable flashlight.

4400 Lumen LED Flashlight

The Nitecore i4000R is a powerful tactical flashlight that delivers 4400 lumens. It features four Cree XP-L2 V6 LEDs giving it a very floody beam. While it does still have a hotspot, the beam is still extremely wide thanks to the four LEDs and the shorter reflectors. You still get some distance with this light and it has a max beam distance of 230 meters.

I really like the design of this flashlight. Nitecore made it look great with a tactical design and feel to it. It’s a bit larger at about 6 and 1/4 inches long, but I could still see it being used as an everyday carry flashlight just due to the slim compact size of it. However, it is a bit heavier so probably not best for everyday carry. It does feature a removable, two-way, and reversible pocket clip and one of the coolest part is that you have a few places on this LED flashlight to put the pocket clip on. So you can carry the flashlight how you want and place that pocket clip where you want. Due to the design and the pocket clip, I want to carry this as an everyday carry flashlight even if it’s a bit larger and heavier than I would like.

tactical flashlight with holster nitecore i4000r

Another option to carry the light, it does come with the NTH20 tactical holster that clips onto a belt and allows you to quickly release the flashlight anytime you need it. It’s quite secure and a great option, but I know some users prefer more flexible holsters that cover the entire flashlight for protection. It depends on your preference. For tactical flashlights, I do prefer a quick-release belt clip because it allows you to quickly access your light.

Nitecore i4000R 21700 Flashlight

So the battery situation with this light is a little interesting. It’s a 21700 flashlight, but it can only use a proprietary 21700 Nitecore battery that has positive and negative polarities at both ends of the battery. You can’t use any other 21700 batteries in it nor can you use 18650 batteries in it.

However, the i4000R flashlight can be equipped with two CR123 batteries when using the included battery magazine that comes with the light. So you do have two choices of battery types, but the 21700 battery is proprietary. On top of that, you’re not going to be seeing the same outputs and run times using CR123 batteries. So if you want the full output and the all the run times that the specs show, you’ll have to use the Nitecore 21700i battery. The good news is this tac light comes with this battery and the bad news is if you want backups you’ll have to purchase that specific battery. Either way, I appreciate that it can run on CR123 batteries especially since the 21700 battery is a proprietary one

21700 flashlight nitecore i4000r

There is a battery capacity indicator located around the head of the flashlight. This indicator will flash to indicate the battery voltage when you first insert the battery. While the light is on, the indicator will be constantly glow or flash. If the indicator is constantly on, the battery is above 50%. If the indicator is slowly flashing then the battery is below 50% and if you see quick flashing then it’s below 10%. It’s easy to remember and the quick flashing will definitely get your attention to let you know it’s time to charge your battery.

USB-C Rechargeable Flashlight

The i4000R tactical flashlight is USB-C rechargeable so you’ll be getting a faster charge with this light as opposed to a micro USB. When it comes to 21700 batteries, I highly recommend going for a flashlight with a USB-C charging function because these batteries provide a lot of energy and take a while to charge. 

usb-c rechargeable flashlight nitecore i4000r

The USB-C port is protected by a rotatable cover just like the Nitecore P22R I reviewed recently. I like this rotary cover design because it’s a lot easier than messing with silicone port covers. The internal port is also waterproofed so if you accidentally forget to close off the port, it’s protected from rain and water which is really nice.

While you’re charging the light, you can see a charging indicator on the tail of the flashlight. It’s very simple; the indicator will blink while the i4000R flashlight is charging and will be constantly on when the battery is fully charged. Not much thought process goes into it but it’s nice to be able to know when your flashlight is finished charging.

Tactical Operation of the i4000R Rechargeable Flashlight

I love the user interface of this tactical flashlight. It features a dual tail switch design, excellent for tactical applications. With the main switch you have a momentary on and a constant on. With the mode switch you can cycle through the outputs and have shortcuts to both a strobe and a momentary turbo. It also features a mode memory function which will remember the last brightness level you had. When there’s a mode memory function, a momentary turbo is excellent. So the flashlight isn’t always going to turn on turbo if you don’t want it to, but you can access it immediately if you need to. 

nitecore tactical flashlight i4000r

The i4000R tactical flashlight comes with 6 total outputs which includes five brightness levels and the strobe. The brightness levels are as follows: turbo 4400 lumens, high 1100 lumens, mid 330 lumens, low 50 lumens, and ultra low at 2 lumens. With the ultra-low you’ll get a 380 hour run time which is very impressive. I could see this making an excellent outdoor flashlight as well. The flashlight cycles starting from low and going up to high which is my preference so long as there’s a fast way to get to turbo.

Other Tidbits About the Nitecore i4000R Tactical Flashlight

Just a few of the things I want to mention about this flashlight, it does feature some nice heat dissipation fins but it is still going to get hot. While it doesn’t get quite as hot quite as quickly as many other high-powered flashlights I’ve written about, it will still slowly increase in temperature. It does feature an advanced temperature regulation or ATR which means it’s going to bring down the output once the light senses it’s overheating. This is going to protect the internal components and it’s something you’re going to want in any high powered flashlight.

The i4000R is extremely durable. I’ve reviewed many Nitecore flashlights and their durability is incredible. With this LED flashlight in particular, it features protections inside the light specifically designed for shooting a weapon. We have to be careful when it comes to finding tactical flashlights that can be weapon mounted due to the fact that many are unable to withstand recoil. The Nitecore i4000R will be able to withstand the recoil of your weapon making it an excellent weapon light.

best tactical flashlight nitecore i4000r

Final Thoughts on the Nitecore i4000R Flashlight

Pros: I think that just about covers everything with this light. I like the nice floody being that it has. It does make it a great general use flashlight, tactical flashlight, and outdoor flashlight. I also appreciate the combination of the mode memory function and momentary turbo. Getting to turbo quickly is important with any tactical flashlight. I also like that this flashlight can run on two different types of batteries and that it is USB-C rechargeable with that rotatable protective cover. The indicators are great, the outputs are great, and there’s a lot to love about this flashlight.

Cons: One potential issue with this LED flashlight could be that it can only accept the proprietary 21700 battery. Because it’s also able to use CR123 batteries, the proprietary battery doesn’t concern me too much. But I know some users are really against proprietary batteries. 

Another thing to mention would be that while it is an excellent flashlight to weapon mount, many people who mount flashlights prefer more of a throw light and this light has more of a flood. I do appreciate the floody beam, but many hunters and tactical users who mount their flashlights onto their weapons may want something that has the more focused beam.

Conclusion: This is one incredible flashlight that has a lot of features to talk about. It has a lot going for it making it one of the best tactical flashlights of this year I would say. If you’re looking for an extremely high-powered compact tactical flashlight, check out the Nitecore i4000R.