Instead of using batteries or charging with a cable, HydraLight is a rugged, durable flashlight that switches on and off like traditional models—but claims to run completely on water.
The company tells us HydraLight works using Hydra-Cell Technology:
- Remove the Hydra-Cell from the body of the flashlight.
- Immerse the Hydra-Cell in water, at which point it will begin generating power.
- Place the Hydra-Cell back into HydraLight, and you'll have up to 100 continuous hours of light on a single water charge.
On the outside, HydraLight features a rubberized armor coating that makes it ideal for use in severe weather. And by simply expanding the barrel and placing on a flat surface, we’re told HydraLight can be used as a hands-free lantern.
Having to constantly check your flashlights for batteries is a chore—especially if you forgot and the power suddenly goes out, you need more light in the garage, or you’re in need of some illumination on a camping trip.
But can HydraLight’s Hydra-Cell Technology make this inconvenience a thing of the past? Is it the only game in town?
Let’s start by taking a look at how it works.
How Does HydraLight Work?
We’ll talk about some variations in a second, but functionally, HydraLight works like any other flashlight; a power source illuminates a bulb, which projects light in any direction it’s pointed.
Instead, the main difference with HydraLight is that its power source uses water to generate electricity.
While there are many different types of batteries, most function with basically the same parts: The cathode (the positively charged end, usually made of metal), the anode (the negatively charged end, typically made of a different metal), and the electrolyte.
The electrolyte in most batteries is an often-toxic chemical substance where electrons from the anode’s metal are released into the electrolyte, which are then accepted by the cathode’s metal. This completes the circuit and generates an electrical charge.
For an in-depth look at the process, MIT’s School of Engineering features a great explanation.
Using Water as an Electrolyte
How does this relate to HydraLight? While the manufacturer doesn’t provide any additional details and we didn’t test the flashlight ourselves, the general idea is that the cells in water flashlights already feature a built-in anode and a cathode.
When you supply water, you’re providing the electrolyte, or the liquid where electron transfers can occur. This completes the circuit and powers the bulb.
Longevity & Light Output
Although this is a novel method of providing light, it’s certainly not new or unique to HydraLight. In fact, a quick online search for “water flashlight” will reveal that you can build one for only a few dollars in parts.
The biggest difference between homemade models and mass-produced ones like HydraLight is that DIY projects often won’t remain powered for more than 30 minutes with normal tap water. The light output isn’t anything to write home about, either.
How Does This Compare to a Traditional Flashlight?
According to the manufacturer, it’ll provide up to 100 hours of run time, although we’re not told anything about how much light it outputs (measured in lumens). Other unknowns to consider:
- How long will you need to immerse HydraLight’s cell before it can be used?
- Will you need to keep a certain amount of water inside HydraLight to work, or does its cell feature material that can absorb and hold water?
- Will the use of water make HydraLight prone to bacteria and mold accumulation?
- Is HydraLight’s cell heavy? Will all the added water (if required) make it even heavier?
- How long will the cell last? Is it easily damaged?
We’ve reached out to the manufacturer with some of these questions and will be sure to update this review as soon as a response is received.
Now, how does this compare to the competition?
Are There Other Water Flashlights Like HydraLight?
If you search online for “water powered flashlight,” you won’t find anything identical to HydraLight.
However, we did find the Eton American Red Cross Blackout Buddy, which features a rectangular design, with three LEDs that can shine continuously for up to 72 hours.
Outside of this, we didn’t come across any mass produced water powered flashlights during our research.
This Red Cross option can be found online for less than $10. Comparatively, what will you pay for HydraLight?
How Much Does HydraLight Cost?
HydraLight is available in three different pricing options, including free standard S&H (additional options are available for more money):
- 1 HydraLight: $39.95
- 2 HydraLights: $67.90
- 3 HydraLights: $95.88
Regardless of the quantity purchased, HydraLight comes with a 60-day, risk-free money back guarantee, less S&H. In order to request one, customer service can be reached at 844-734-3650.
How Practical Is the HydraLight?
As battery and bulb technology has improved over the years, we’re now at a point where most of us have access to small, inexpensive, well-built lighting that can withstand a lot of abuse and deliver solid performance.
This includes tactical flashlights like TacLight, Atomic Beam USA, and Shadowhawk X800; lanterns like TacLight Lantern, emergency models like LuminAID, and options that defy categorization, such as Accordion Light and Lumio.
This is obviously in addition to standard flashlight models you can find at just about any corner store or mega-retailer for just a few dollars.
Granted, nearly all of these options are powered by standard batteries, so, if they run out of juice, you’re out of luck. Comparatively, HydraLight’s water-powered cell seems like it might provide light in an emergency situation, without a traditional power source nearby (as long as you don’t find yourself in a desert!).
However, keep in mind that there are many other options that can provide emergency light, such as shake, hand-cranked (also known as wind-up flashlights), and other mechanically powered/kinetic flashlights. You’ll find many of these models are priced competitively with HydraLight, too.
Here’s a quick comparison:
Pros: Nothing required other than movement. Often very durable. Batteries are replaceable in higher-end models.
Cons: Will only remain powered for 1-2 hours before more input is needed from you. Light output might be limited. Batteries can lose their ability to hold a charge if not used for long periods of time.
Pros: Other than water, no input is needed. According to HydraLight, it will provide up to 100 hours of run time.
Cons: What happens if you’re nowhere near water? Light output generally won’t be as great as traditional flashlights. How long will these batteries continue working (after all, this doesn’t seem to be widespread technology)?
Given these factors, as consumers ourselves, what do we think about HydraLight? If we were in the market for an alternative-powered flashlight, while its concept is undeniably cool, HydraLight doesn’t seem like it would be as practical as more mainstream options.
This might ring especially true if you’re looking to store HydraLight in any place other than with your hunting or camping gear, such as in your glove compartment, emergency kit, or in the garage.
If you feel like giving HydraLight a try, though, the good news is that the manufacturer provides a 60-day refund policy. Just keep in mind that you’ll lose a few bucks in return shipping.
What did you think about HydraLight? Did it work like the manufacturer claimed? Was it useful? Practical? Give us all the details in your review below!