This round of testing, we gave the SteriPEN Ultra a whirl. It is similar to other SteriPEN products in that it uses ultra-violet light to get rid of harmful microorganisms in your water. Different from the SteriPEN Adventurer, the Ultra is rechargeable; instead of carrying batteries, you charge it from your solar panel, at home from a wall charger or computer. It can also brighten your day by giving you a little smiley face to let you know your water is ready to drink.
SteriPEN Ultra Review
Compare prices at 2 resellers Pros: Eliminates viruses, lightweight, rechargeable
Cons: Limited battery life, limited treatment capacity
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Our Analysis and Test Results
This contender plugs into a wall and can create a seal with a store bought water bottle. If you're going to be traveling somewhere there is a lot of sediment, consider bringing a filter instead.
There is a lot of blind faith put into SteriPEN when using this unit — but supposedly ultraviolet light treats all kinds of nasty things in your water including viruses, protozoa, and bacteria. The Ultra is fast and effective against viruses as well as protozoa and bacteria, which is an advantage over most of the pump filters, except for the MSR Guardian. The way UV light works is that it does not actually kill pathogens, but instead scrambles the DNA of the organisms so that they cannot reproduce, rendering them harmless to you. We think this feels a little spooky.
We prefer the rechargeable model to one with batteries. It seems like more and more people are bringing an external battery or solar charger for all their various electronics and this is just one more item to charge versus bringing separate batteries for. There are a few drawbacks: it only works in bottles with openings at least the size of a Gatorade bottle, and it does not work well in hydration bladders. Also, it does not treat the water on the threads of your bottle, which chemical treatments like Aquamira Water Treatment Drops do. This is not an issue with pump filters or the Sawyer S2 Foam Filter since your bottle never touches untreated water, but with the SteriPen, you dip your bottle right into a water source, and where you sip is not sterilized.
Ease of Use
The Ultra is straightforward: fill your bottle, dip the pen inside the mouth of the bottle, push the button once, and agitate it around for 90 seconds.
We like the Ultra's smiley face indicator that lets you know when your water is good to drink (or frowny face if something has gone wrong) and think it is more precise than the Adventurer's red or green light, which earned it a 6 out of 10. The Platypus GravityWorks was the only contender in our testing to score a perfect 10 out of 10, with the MSR Autoflow Gravity Filter and MSR Guardian dominating the ease of use metric.
The SteriPEN's UV bulb is good for up to 8000 liters and will last for 50 uses (liters) in one charge. If you're drinking about four liters of water a day, this could technically last you 12.5 days of water purification. The downfall to all these SteriPEN units is that you can only treat one liter at a time, so it is difficult to treat high volumes of water in one sitting. It will be a time-consuming process to treat a group of 5's water for the whole day with the Ultra; we think a gravity filter like the MSR Autoflow Gravity is the best choice for groups.
It takes 90 seconds to purify a liter, which is comparable to the time it takes to pump a liter from most of the other pump filters, like the Katadyn Hiker Pro but it can seem like a long time as you wave the wand around in your water bottle. The fastest treatment system we tested was the Katadyn Gravity Camp.
The Ultra is a comfortable six ounces including its cushy carrying case. This is the heaviest of the SteriPEN models, but still much lighter than any pump filter and it has the benefit of treating viruses. The MSR TrailShot also weighs 6 ounces and is a much more versatile product. If you're looking for an even lighter solution, we like the Aquamira Treatment Drops for a lightweight, effective treatment.
Since the UV technology deactivates viruses; this method is perfect for international travel or places where water is particularly contaminated. We think the Ultra would be best for short backpacking trips with one or two people. We'd recommend using it in areas where the water will be clear and sediment free because the Ultra does not filter out debris; although it will be safe to drink, it may not be the tastiest of water. A separate pre-filter can be purchased as an accessory, but that is just another piece that needs to be carried.
The Ultra is the priciest of the SteriPEN line at $100, but other than chemical treatments is the cheapest treatment option that eliminates viruses. For a great filter that is lighter than the SteriPEN, we prefer the inexpensive Sawyer Mini, although it does not treat viruses.
Because of its finicky battery life and inability to treat large quantities of water, we're not super keen on taking the Ultra into the backcountry for extended or group trips. It could be a good choice for a solo hiker going into the high alpine where the water is clear, but we would still recommend bringing a backup treatment like Aquamira or MSR AquaTabs.
— Jessica Haist