The Heliotek HTE-1 is made by Heliotek and is the incarnation of a high end lighting device. Designed with pure functionality in mind it was made to be one of the most reliable lights you could get your hands on. Whether spelunking, hiking, fishing, camping, working on a oil rig in the Arctic, climbing the Alps, crossing the Sahara, or recreational diving in the Caribbean, this light was designed from the start to be a dependable tool that just won't let you down.

This is actually the second incarnation of this model of light. The first, although a fantastic light, surprisingly did not meet with the maker's satisfaction. Convinced that they could make it better, Heliotek stopped producing the first version and came out with this new and updated version. An archive of the original review is available HERE.

The HTE-1 head and scratchproof coated lens is made from GE Lexan, one of the toughest plastics around. On the front of the head is a spring-loaded polycarbonate diffusion lens which both protects the primary lens and serves to diffuse the beam for close-up work. The battery compartment is made from stainless steel covered with Santoprene TPE for grip. This thermoplastic elastomer offers a constant service temperature range from -60 to 135°C (-81 to 275°F). The head is much larger than the body in order to contain the very deep reflector which concentrates the light of the white Luxeon I high dome LED into a tight spot. A notched bezel ring at the top of the head acts as a standoff to protect the lens (when the diffusion lens is removed) and also allows light to leak out if the unit is placed on its head while on, so you know that it's still on. At the other end is a tailcap that holds the breakaway lanyard. The tailcap is designed to rotate freely and allows the light to stand on its tail despite leaving the lanyard attached. A removable/reversible clip is also included on the battery tube. The entire light floats when used with the included Energizer L91 lithium AA cells.

Inside the head, behind the clear, scratch resistant coated Lexan lens, is the deep reflector followed by the Luxeon I LED, followed by a current regulator boost circuit. This circuit provides a constant 330 mA to the LED for the 6-8 hour battery life. An independent source has confirmed that this light has dead flat regulation, (meaning very constant output) for around hours on the supplied batteries before dropping to very low levels. It doesn't get any better than that when it comes to regulation!

The clear polycarbonate diffusion lens is easily opened using just one hand. On either side of the top of the bezel you can see two "ears" that protrude slightly from the sides. By squeezing these ears with your thumb and forefinger the lens holder flexes and the lens itself pops back out of the way. The entire assembly is then removable by squeezing again and pulling it off the front of the light.

Output is in the form of a very tight spot (with the diffusion lens retracted), which is very unusual for an LED light. Surrounding the central spot is a wide, bright surround, followed by a dimmer spillbeam. With the diffusion lens in place you get a nice soft flood of light in the direction pointed. My numbers show about an 8% drop in overall output with the diffuser in place. Color temperature of the white beam is very good which allows for good color rendition across the visible spectrum.

   
Beam at one meter at target center with diffusion cover on, then off.

The runtime graph was completed using the included Energizer L91 batteries, which are the only batteries recommended for the light. The light went, as advertised, about 7 hours before dropping out of regulation. The regulation curve is one of the best you can have - almost dead flat. Even more good news is that when it drops out of regulation the light then drops to a very low but usable level of output for several hours thereafter. It won't leave you completely in the dark even when the cells are nearly dead.

Runtime completed with included "Energizer L91" batteries. More information on runtime plots is available HERE.

Alkaline cells are not recommended for this light, but being the intrepid reviewer that I am, I gave it a shot anyway. Note that by doing so, I just voided the warranty on the light. Output was the same, but as the graph below shows, you get less than 2 hours of output and a runtime curve that isn't quite as flat as with the L91 cells. Also, the light will not float if alkaline cells are used. If you drop it in the drink, it's sleeping at the bottom with King Neptune.

Runtime completed with "Varta RedCell alkaline" batteries. More information on runtime plots is available HERE.

The switch is actually tucked inside the sealed head. On the outside of the head is a mechanical "switch" that actually holds a magnet which activates the switch inside. As a result, there is no hole in the head where the switch sits. The mechanical external portion of the switch is recessed so that accidental activation is very unlikely.

The switch has 4 positions. Click the textured slider to the right and you can press the switch forward for constant on, back for constant off. A firm click accompanies activation and deactivation. Click the textured slider to the left and you can move the switch easily forward and back for momentary operation, but it will not lock in either position. A spring inside the switch returns it back to the off position in momentary mode when released.

The head of the HTE-1 is completely sealed. Only one Buna N O-ring is needed to seal the body to the battery tube and a spare is included. Each unit is reportedly tested to a pressure equivalent of 45 meters (150 feet) of water depth. Keep the O-ring occasionally lubricated with silicone grease and it should last a long time. A spare O-ring is included with the light

Ergonomics: Easy to hold in a variety of grips, and the switch is easy to activate with your thumb. The ribbed Santoprene cover on the battery tube provides a fairly good non-slip gripping surface.

Size compared to a common 2AA aluminum light

Only Energizer L91 AA lithium batteries are recommended for use for several reasons. The L91's don't produce gasses under normal operating conditions, they operate well in cold and hot temperatures, their light weight allows the unit to float in water, and they supply enough power to give the 6-8 hour run time. Using any other type of battery may be possible, but it voids the warranty on the light.

A belt sheath is included and they even went all-out on that as well. It is heavy duty nylon with a belt loop on the back. Inside the cover, which is held down with that heavy-duty-plastic-velcro-like-connector-stuff that looks like a field of mushrooms, is velcro retaining strap that wraps around the head of the light for extra security. On the front is a Velcro flap pouch that holds 2 spare batteries and includes two zip-lock pouches to keep your batteries dry. A breakaway lanyard is also included and is attached via a roll-pin to lock it in place. A spare roll-pin is included.

Heliotek also offers a tripod and mount ring for the HTE-1. The tripod mount ring is made of Lexan and is manufactured by Heliotek. The "pocket pod" is from a third party and is supplied along with the mount ring. Cost is about $10.

What I Liked: Waterproof, Tough/impact resistant, Current based regulation, Long battery life, Bright, Easy battery change, Lightweight, Stands up on end, Floats

What I Didn't Like: Nothing

Other Things I Noticed: Energizer has the exclusive rights to make L91 batteries. At about 2.00-2.50 each, they are a bit expensive compared to most others. At least the light runs for over 6 hours on a set of 2.

Conclusions: If you ever wanted to know what it takes to make a light designed for extreme conditions, just look to the Heliotek HTE-1. They, and everyone else out there, will have a hard time topping this one. Some of the highest quality components, materials, and design have gone into this product. It has a funny shape and looks a bit out of proportion, but it is one of the best serious-use lighting instruments I've ever seen.

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