Gear Review: SteriPEN Freedom Handheld Water Purifier

I’ve been using a SteriPEN for water purification since 2006 when I bought the first generation of the Adventurer as an alternative to chemical treatments (see the review at here). I’ve taken that device on countless climbing trips into the backcountry all over the country. Most recently, last year, I took it on a 13-day blitz of the John Muir Trail, a 211-mile hiking route through the Sierras. I took two extra sets of batteries (I only needed one) and no backup treatments (and I didn’t need them). In fact, when one of my hiking companions discovered he had miscalculated the amount of chemicals he needed, I treated his water with the SteriPEN as well.

The primary criticism I had of that original SteriPEN Adventurer – the sometimes finicky water sensors – was addressed with an updated version that employed an optical water sensor.

SteriPEN has continued to innovate since then, and it’s most recent iteration is the SteriPEN Freedom. In just about every way, the SteriPEN takes a great product and makes it perfect.

I’m not going to go over the general principles behind using UV light to treat water, or the basic procedures involved in using a SteriPEN (for this information, see the previous review of the Adventurer). Rather, I’d just like to highlight the features of this newest model.

Most notably, the Freedom is the smallest and lightest SteriPEN yet. Weight has dropped to 76 grams (2.7 ounces) from the Adventurer’s 105 grams (3.7 ounces) with batteries. This thing is insanely light and compact - not much bigger than a couple bottles of Aqua Mira or iodine. The weight savings are primarily achieved but integrating a Lithium Ion rechargeable battery (think cell phone battery) into the device. This addresses an inconvenience of the previous model: Gone are expensive, heavy, and hard to find cr123a batteries! Instead, a concealed Micro USB port allows quick recharging of the battery via an included wall charger and cord. For those keeping score, this is the same cord that charges the Petzl Core headlamp system. That means that now I can recharge all of my electronics in the field with any USB power source such as a solar panel or USB battery pack. Not necessary for short overnight trips, but indispensable for expeditions of any significant length.

Activation is also simplified. No longer do you have to press a button once or twice. All that is required is immersion into water – the devices senses this and turns on and automatically runs for 48 seconds to treat 500 mL of water. Since I typically treat one liter at a time, once the Freedom completes a cycle, I pull it out and immediately dip it in again – without fail the Freedom reactivates and runs for a second cycle to finish the full one-liter treatment.

A bright green LED on the top of the Freedom begins blinking and the main bulb also illuminates to indicate that a treatment is in progress. Upon completion, the main bulb goes out and the green LED remains lit, unblinking, indicating success.

SteriPEN estimates 40 half-liter treatments per charge, and I found this to be accurate. The bulb is rated to 8000 treatments, and both the bulb and battery are replaceable by SteriPEN. There are many safeguards in place to prevent incomplete treatments based on errors, removal from the water, or lack of battery life.

The Freedom has an integrated white LED light as well. Not bright enough to navigate trails, but suitable for basic camp tasks. Activation involves three quick back and forth “rotations” of the device – this turns the light on for a 3-minute duration. There are no buttons on the SteriPEN. It is simple and svelte. A compact, rubberized casing feels durable and is easy to grip while in use.

I’ve had a chance to use the SteriPEN on a few multi-day climbing adventures in Nevada and Arizona. It has performed flawlessly. This summer it will accompany me on another extended Sierras trip – look for a long-term follow up review.

The Freedom comes complete with a Micro USB cord, an AC wall charger, a Neoprene pouch, and instructions.

$119.95
steripen.com/freedom-travel