In any type of “tactical” operation, versatility strongly matters. Weapons that fire more than one kind of ammunition. Tools that can serve more than one purpose. Have you ever considered why a multi-tool is so common? Because you can do so much with it. Where flashlights are concerned, there are three key considerations: 1) It has to produce enough light to be useful (that’s situation specific); 2) it has to have a reliable power source; 3) it has to be durable enough to put up with the abuse it’ll surely see and still work. Light output and durability are functions of design and usually limited. That’s how it used to be for power sources too, but stand by... take a look at the Sentinel e3, so named because it will use three different power sources.
The first and most powerful fuel source for the Sentinel e3 is the 16340 rechargeable unit. Using it, the Sentinel can produce 400 lumens of light for an hour. The rechargeable battery can be recharged in the light via a USB cord plugged into wall or your vehicle... or any other USB port that provides power. The “throw” distance for this light/power combo is 111 meters. That’s a long way to see with a light that will fit in your hand - and not stick out much at either end.
The second fuel source is a CR123A 3V lithium battery. Using that fairly common battery, the Sentinel e3 produces 230 lumens for two and a half hours with a throw of 85 meters.
The final fuel option is one of the world’s most common batteries: the AA. Using an average every day AA battery, the Sentinel e3 will produce 90 lumens for five hours with a throw of 54 meters.
Now some folks reading this are wondering what good a 90 lumen light that only has a throw of 54 meters will be. Keep this in mind: “back in the day,” a 65 lumen light with a 30 meter throw was considered sufficient. Yes, brighter is better and farther is an added bonus. Realistically speaking, for tactical purposes, you have to be able to identify your target at engagement distances. Unless you mount the Sentinel e3 on a long gun, your usual maximum qualification distance is 25 yards or roughly 23 meters. So a 54 meter throw is more than double what you’d need it for “tactically.” For searches, farther is better, but so is brighter. So use the rechargeable battery unit BUT... keep a CR123A handy for backup and even some AAs on hand. It’s better to have a not-as-bright light at hand than no light at all in low light conditions.
The Sentinel e3 has an overall length of just under 4” and a body diameter under .9”. Via a double tap on the rear-tail cap activation button, you can go from high power to low power quickly. Lower power is 27 lumens using the rechargeable battery, 18 lumens using the 3V lithium battery, and 10 lumens using the AA battery. Run time on low power is 15 hours, 30 hours and 44 hours respectively.
The light comes equipped with a reversible and removable clip for convenience of carry. Without the clip, the light fits nicely in most standard flashlight carries. The bezel is the same diameter as the rest of the light which makes it different from most tactical lights on the market. That said, while I would still recommend this as secondary / backup light, 400 lumens makes it more than capable as a primary duty light.
All the published material for the light says it will easily take a drop from a two meter height. Not satisfied that represents the trials and tribulations a light might be put through on the street, I took the Sentinel e3 I had for testing and underhanded it twenty or thirty yards down the street. It bounced well thanks to the foam wrap on the handle portion and it continued to function without pause.
A quick Google search for “ASP Sentinel d3” reveals a price point in the $80-$85 range, and that’s a fantastic price for a rechargeable 400 lumen light that has two backup fuel source options.
