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The Triatholight: A 300-Hour Flashlight That Seems Too Good to Be True

David Pogue

Crowdsourcing sites like Kickstarter and Indiegogo let inventors appeal directly to the public for funds. They’ve made a lot of entrepreneurial dreams come true.

If you’re inspired by the inventor’s pitch video, you send some money. It’s not an investment; you don’t get rich if the invention becomes a hit. But you do get some memento — a T-shirt or a discounted version of the invention once it’s manufactured — and the rosy glow of knowing that you helped bring a cool idea to life.

Until now, there’s been only one problem: You had no way to know if the invention was actually any good. You had to trust the inventor’s video.

That’s the beauty of our Kickstarter reviews. We actually test the prototype, find out how much promise it has, and help you decide if the thing is worth funding or buying.

Today’s invention: The Triatholight flashlight. It’s on Kickstarter here.

The claim: This LED flashlight burns brightly for well over 300 hours on a single D battery. (Normal D-cell flashlights last about six hours.) Also, your battery doesn’t slowly drain in this flashlight when it’s stored for months.

The Triatholight: A 300-Hour Flashlight That Seems Too Good to Be True

Price: $54.

Goal: $10,000.

Status: With eight days left in the Kickstarter campaign, the project has already met its funding goal. 

What I tested: The creators shipped me a fully working prototype: a flashlight containing a single D battery. The final version will be “IPX-5 rated waterproof” and will have improved LEDs, more reliable placement of the battery-assist module, and minor refinements.

What I learned: As a tech reviewer with a passion for invention, how could I pass up an email pitch like this one?

I’m Brett DOnofrio. I started Enduring Technologies with my dad and my grandfather, who’s been an electrical engineer for 50 years with over 25 patents, including electroluminescent indiglo for Timex watches.

We came up with a battery assist module that greatly enhances the life of batteries. We put it in a flashlight because that’s something that everyone needs in an emergency — and the battery’s always dead.

We decided to start a Kickstarter page to fund our product, the Triatholight. It’s a compact waterproof flashlight with 32 LED bulbs, rated at 20,000 millicandela. It runs on just one D cell battery for 300+ continuous hours — and has NO draw on the battery when it isnt in use.

Well, wow. If the three-generation D’Onofrio team is correct, then it’s really on to something.

My family has managed to accumulate five flashlights. When Brett’s email arrived, I went to see how many of them would still turn on.


All of them were dead.

So Brett sent me a prototype of the Triatholight. It’s just what you’d expect of a compact flashlight: black aluminum, one D battery inside, 32 tiny LED bulbs, excellent brightness. If such a flashlight really could last, say, 50 times as long as a regular one, well, that’d be worth buying.

But how could I test his claims?

The longevity question should be easy to answer. I bought a hardware-store flashlight with the same number of LEDs. I noted the time and date, turned them both on, and let them sit.

As I write this, the Triatholight has been shining for 216 hours. It’s only slightly dimmer now than it was nine days ago. (I’ll update this statistic until the Triatholight battery is dead, but I wanted to post my review while the Kickstarter campaign was still in progress.)

Update on Day 16: The flashlight is still on after 387 hours, slightly dimmer. (The hardware-store flashlight died completely 2 days ago.)


The hardware-store flashlight, meanwhile, was too dim to be usable after 48 hours. A few of the LEDs were still feebly glowing, but you couldn’t read by it.

Now, here’s the thing: It turns out that LED flashlights, with that many LED bulbs, that require only one D battery, are rare. I couldn’t find one in any local shop. So while my hardware-store flashlight has the same number of LEDs, it runs on three AAA batteries instead of one D battery. That’s not exactly apples to apples.

With some Googling (or, rather, Amazoning), I turned up a couple of other options that do use D cells. This one is the most like the Triatholight: aluminum body, one D battery, 21 LEDs (the Triatholight has 32). Battery life: only 30 hours. Winner: Triatholight.


Here’s another option: A Rayovac. Battery life is 160 hours on one D battery, but the light is dim (only 7 lumens), and there is only one LED (not 32). Winner: Triatholight.


So it seems that the first claim of the Triatholight is true: Its “battery-assist module” assists its battery in greatly outlasting regular flashlights, at least by a factor of 10.

The second claim — that this module prevents the battery from dying as it sits on the shelf, unused — is harder to test. If I waited a few years to confirm it, the Kickstarter campaign would be long over, and this review would be pointless.

It doesn’t seem like this claim could be true. Batteries slowly self-drain all by themselves, even in their packages. For alkaline batteries, it’s about 3 percent a year, according to

I asked the inventors how their module could affect a battery’s slow self-discharge. The reply wasn’t especially specific:

“Thanks to how our tech works with the battery, without going into too much detail, it keeps the battery from being affected like it would be in other flashlights, or out on its own/in the packaging.”

In other words, “It works because it works.”

The controversy. Since I started testing the Triatholight, an ugly battle has erupted in the comments on its Kickstarter page.

One detractor, Arthur Day, calls Brett a “scammer,” claims that the photographs are “faked,” and writes:

“Your circuit is probably a charge pump. You put 1.5V into a charge pump, you may get 3V out, but that extra 1.5V is not free. 3V out at 800mA means you have to supply 1.5V at more than 1600mA. The point is you are simply not using the LEDs you have anywhere near [their] capabilities. You are probably supplying each with less than a mA, not the 25mA each they need to produce 20cd.”

Another detractor, Tom Uneken, writes: “About the luminous flux: I calculated the theoretical maximum lumens output for the LED you claim to be using, which is [241.28lm]. It DOES NOT make sense to keep saying the output is about 300lm at full power. That is NOT POSSIBLE.”

A discussion on this lighting-engineer discussion board also comes down hard on the Triatholight’s claims.

Needless to say, the D’Onofrios insist that their claims hold up.

It’s impossible for me to judge. The commenters speak in electrical engineering terms; the D’Onofrios, in an effort to protect their secret, don’t respond with much specificity.

When I asked for a layperson’s description of how their module works, for example, this was the D’Onofrios’ response:

“The Triatholight’s battery assist module provides a controlled battery discharge rate, still providing the power required by the LEDs. This is accomplished by a novel circuit design, which is automatically continually changing. The circuit concept has been around for many years, but could never do what our modification of the circuit is able to do.

“We are not talking about perpetual motion, and we are not talking about conservation of energy; we are talking about the coefficient of performance, which can be greater than 1.

“It is not our intention to disclose the details of exactly how we have accomplished this.”

The bottom line: So where does that leave us?

It’s clear that a single D battery in a Triatholight lasts at least 10 times as long as a D battery in a standard flashlight. (Again, I’ll update that figure when my test battery finally dies.)

I’m not going to wait to test the claim that the batteries won’t self-discharge over the years. But I don’t see how it can be.

I doubt the D’Onofrios faked their photos. In fact, their YouTube video here makes absolutely clear that a nearly dead D cell battery, too weak even to turn on a regular flashlight, is still strong enough to light up the Triatholight.

I wonder if the key to the controversy lies in the light output of the flashlight — the number of lumens. Even the D’Onofrios’ bitterest critics acknowledge that the Triatholight might indeed get 300 or more hours from one D battery if it’s not very bright. (Mine is plenty bright, but I have no way of measuring its lumens.)

So: Should you fund this Kickstarter project?

In general, people fund crowdfunded projects mostly because of the excitement, the sense of participation, the desire to support the passions of clever inventors — not just to buy another gadget. In that aspect, the Triatholight deserves your attention. There are some non-ignorable signs that it really is something new, or at least unusual.

(The D’Onofrios are offering a money-back guarantee, by the way.)

And what if the “battery assist module” turns out to be, for example, just a refined “joule thief” (an existing invention described here)?

Worst case, you’ve paid $54 for a rugged aluminum waterproof flashlight that makes a battery much longer than regular ones — and helped conduct a fascinating experiment in physics, engineering, and public opinion.

You can email David Pogue here. Follow Yahoo Tech on Facebook for all the latest.