SteriPEN

For a long time I used a PUR (now Katadyn) Hiker. Good system, but I wanted to reduce bulk and weight. Not to mention the whole aspect of a clean hose and a dirty hose, and trying to keep them separated. And pumping when the filter has become silt logged can become a Herculean task.

So I decided to give the SteriPEN a try. Like anything, there are pros and cons. The good points are that it is indeed light and small. To treat the water is a quick process. There are two small metal ovals on the side of it and they have to be in the water before it will work. Once it’s in the water, press the button, the glowing blueish/greenish light will come on, swirl it around, and a minute or so later, done.

One thing I should point out is that it doesn’t actually kill the organisms, it merely screws up their DNA to the point they can’t reproduce.

Since this system doesn’t filter water, I got one of the bottle top pre-filters they offer. It screws onto the top of a Nalgene and works very well. Very quick. I haven’t timed it, but I’d say 15-20 seconds to fill a 1 liter Nalgene, less than 30 seconds certainly. (It doesn’t however fit perfectly onto the stainless steel Guyot bottle. It sort of does, but doesn’t really lock down all the way.) Like the MSR Miox, the SteriPEN doesn’t really alter the taste of the water. If it’s a really skanky pond, it won’t make the water taste like water from a spring. But for me up till this point anyway, this filter has done a fine job of filtering out any particulate and other funky stuff. The filter attachment is also quite straight forward to clean.

I enjoy the fact that using the system of the pre-filter and the SteriPEN, I can fill up quickly and then move away from the stream and its inevitable insect swarm, and purify it elsewhere. With a pump filter, I would be there for ten minutes, squatting awkwardly as an escadrille of mosquitos swarmed all around me. And it would be worse if the filter was starting to get clogged up.

I’ve taken water out of everything from head water streams to rivers to ponds to bogs to big northern Ontario lakes. So far no problems.

One of the drawbacks of this system is that since the Adventurer needs to be put in the water, it precludes the use of a narrow topped bottle. An old pop bottle won’t work. It needs to be a Nalgene or Camelbak bladder type of unit - ie a large opening. You have to tailor your container to the SteriPEN, but this is true of just about any purification method. I believe the Classic has a rubber portion just below the UV tubes designed to work with plastic water bottles (evian, whatever) It’s designed to put the SteriPEN in until the rubber contacts the bottle mouth, then you turn the bottle upside down, keeping the pen in the bottle tight so the water doesn’t run out. This way you can sterilize the water in a small bottle. (They do now have this Fits-All Filter. Looks intriguing.)

Another downside is that any water on the threads at the mouth or on the outside of the bottle or in the cap aren’t actually going to be treated. Since the device has to be immersed in the water, water on any of those areas wouldn’t really be treated by the UV light. When using a method like PolarPur or some other type of chemical treatment, the instructions tell you to let some of the chemically treated water dribble over the threads in order to try and kill any organisms that may lurk there. After you’ve swished the UV wand around in the water, it is good to drink, but letting it dribble over the threads would just mean that you are running clean water over them. It wouldn’t have any real ability to kill any organisms the way a chemical treatment would in theory be able to. Now if you used the filter cap I mentioned earlier, it should in theory keep the threads of the bottle “clean” but if you dunk the closure cap in the water, it would in essence be “dirty” and might have the potential of letting giardia or something like it back into the bottle to infect it. I always try to make sure to keep the cap out of the water, but this isn’t always possible.

I suppose if that is a really big concern to someone, they could use a cup to scoop up the water and pour it into the bottle to try and avoid that scenario.

One of the areas where the pump filter I was using had a distinct advantage was in that there is an intake hose, in the water, and an output hose, which went in the bottle or bladder. There was no chance for cross contamination.

The fact that it is battery operated might be seen as a minus in some peoples eyes too I suppose. To be honest, it’s become the deal breaker for me.

On a recent hike around Kejimkujik in Nova Scotia, the batteries died out. (I know that for some reason I took out the original Panasonic batteries and used a pair of SureFire batteries in it, and then put the Panasonics back in.) No problem. I pulled out my extra batteries, put in another pair of CR-123’s (Evergreen), pressed the button, waited for the green LED to start flashing, put it in the water, I got a momentary flash of blue UV light, followed by a rapidly flashing red LED.

It wouldn’t work.

So two days into a week long trip, I was forced to turn to Micropur tablets in my survival kit. Which ran out after 3 days. Then I had to boil water, which used up a limited supply of methyl hydrate. I had intended the alcohol to be used just for boiling water to rehydrate meals, not for purifying water. Eventually I was reduced to using fire to purify the water. Having to stop repeatedly to boil water is a pain in the ass. When it’s the middle of summer and you’re drinking 8 or more liters of water a day, having to wait for your boiling water to cool down is a pain in the ass. Pouring it from bottle to cup repeatedly helped cool it down. But it was all inconvenient to say the least.

When I got home I checked the batteries and they’re fine. According to my battery tester they’re at full power, and they have no problem sending forth a bright beam from either my Sure-Fire or Fenix lights.

I’ve been a bit hesitant about relying on a battery operated device for something as vital as water. I had it proved to me why.

I got in touch with the company, and they told me that based on previous testing and experience, the lesser known brands of batteries are not very good performers. Many of the lesser known brands do not have the capacity to deliver more than 0.5A at the rated voltage. The high quality (well known) batteries can deliver 1.25A at the rated voltage which is why they are able to perform better. Basically, the more famous the brand, the better the quality. Energizer batteries are typically the best for the SteriPEN Adventurer followed by other well known brands such as Kodak, Sanyo, Duracell and Panasonic.

Maybe if I’d spent time over on CandlePowerForums reading up on obscure battery minutia, I’d have known, but anyway... I guess it just never even occurred to me. They worked fine in lights, why wouldn’t they also work in anything else? You know what they say about assuming.

As it turns out, different batteries (especially CR123’s) work very differently in different devices. Surefire batteries are made for tactical lights (low peak amps, maintain max volts for as long as possible, constant load and heat control), while Energizers are made for cameras (strong peak amp draw while charging the flash, then low load and minimal heat issues). Use a battery made for a different application and you will get bad results.

When it comes to, say AAs, I've put them in walkmans, flashlights, GPS’, cameras, radios, etc., etc., and they’ve always worked. Name brand, cheapo dollar store, rechargeable, whatever. They’ve always worked in anything.

Just never dawned on me that it wouldn’t be the same with CR123’s.

I get that cheap batteries that may not let something run as long. But for something to completely not function at all - totally unsat.

When I bought the unit from TADGear, I bought a box of Evergreen CR123’s to accompany it, thinking I’d gotten a great deal. Certainly as compared to buying a single CR123 from a camera store, it was.

The discovery that they lack the oomph to power the SteriPEN though, leaves me unsure whether to be unimpressed with the batteries or the SteriPEN. To me this is a MAJOR flaw in the system.

Finding this out leaves me rather underwhelmed and regretting ever buying the Adventurer to be honest.

If I’d known this in advance I would have opted for one of the AA models. Easier to get, cheaper, and something tells me that they wouldn’t be as temperamental as the CR123’s. Although the SteriPEN website says that only lithium or NiMH, not alkaline AA batteries should be used, because they won’t push enough current.

I guess I could go out and spend another $100 and buy another SteriPEN, one of the AA models. But if I’m going to send another $100 on any water filtration system, I’ll spend the money to make myself a gravity filter.

I’m not denying that I’m a dummy for not checking before hand to see that the Evergreen batteries would work. I made the assumption that they would work fine, and it caused me some grief.

The moral of the story: Either do not use bargain brand CR123’s, don’t purchase the SteriPEN Adventurer or any other model that is powered by CR123 batteries, or don’t rely on a battery powered water purification method.

I’ll get some better CR123 batteries and relegate the Evergreen ones to powering flashlights.

But I’ve already bought the components and I’m making myself a gravity filter. The Steripen is about to be relegated to a backup role.

I think what really bothers me about it all is that I read the instructions when I got the unit, and I just checked them again now. I scoured the instruction pamphlet to locate a date, and it dates from July 2007.

There is no mention anywhere of this issue.

The closest that I can find is a passage which states:

Important Note:
Many brands of CR123 batteries have built in protection circuitry that instantly disables battery function when batteries reach a specific low charge threshold. If this “disable” function is triggered during operation the Adventurer/Traveller will be unable to give the “Low Battery” signal (blinking red LED). Until batteries are replaced or recharged the Adventurer/Traveller will not be operational.

Under “Battery Selection and Installation” it states:

SteriPEN™ Adventurer and SteriPEN™ Traveller use two CR123 batteries. CR123 batteries are nominally 3 volts and are available in both rechargeable (disposable) varieties.

Our testing has shown that a single set of non-rechargeable (disposable) CR123’s will treat approximately 50 liters of water. Testing on rechargeable CR123’s (750mAh) indicates that approximately 35 liters may be treated between battery charges.

But in short there was no mention of certain types of CR123’s being completely non functional in the SteriPEN.

The website recommends certain brands, but doesn’t specifically spell out that certain brands simply won’t work.

I told them that I thought this was negligent on their part. I’m still waiting to hear back from them.