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Monday, July 30, 2012

SteriPen Water Treatment

 “Over-all, I love it for its compact, light-weight attributes, ease of use and neat-o factor.  I use the SteriPen while out in the backwoods for extended periods of time.  Mostly I am riding a mountain bike for all-day rides so I do not have to carry all my water, or will use it on bike packing/camping trips as a water source”.
Water purifiers come in all forms, shapes and sizes. Most are based on filtering out contaminates in order to deliver pure clean water.  The SteriPen takes a different approach with it’s UV light technology.  The SteriPen does not filter the water, rather it wreaks havoc on the living organisms in the water so they can not do harm in your gut.  The user can safely drink the treated water without fear of illness.

Water can be the heaviest item in the pack, but a filter, or this SteriPen, leaves more room for other gear, or just lightens up the pack. With a new set of batteries it is good for up to 100 treatments, and unlike mechanical filters the SteriPen is not damaged by freezing temperatures, or clogged from repeated use.

(UV light (and visible light) seen in a glass of water)

It is simple to use, one click for a liter, 2 for a half liter.  Insert the UV light stick and stir until the light turns off.   When done the SteriPen stores neatly back into its case and into your pack.  All the user needs is a source of water.  The UV light does not kill the organisms, but rather disrupt their DNA and prevents them from reproducing in your intestine.  A sterile bug is harmless they say.  It will eliminate as much or more hazards than a mechanical filter.  Ultraviolet (UV-C) light rays safely sterilize clear water by destroying 99.99% of protozoa (including Giardia and Cryptosporidia ), bacteria and even           -      viruses.
There is a LED that flashes to indicate unit is ready, but can also be utilized as a flashlight.  The test unit did not function like that, however the flashing LED seems to be bright enough to get you around a dark camp site if it did work.  [update: now my flashlight mode works and it is bright enough, but is not powerful by any means]
It is key to understand that the harmful UV light will not penetrate a plastic or glass container, and even will not penetrate the surface of the water, only the visible light will (visible light is just to show that the invisible UV light is on).  Since the UV light does not penetrate the water surface, care should be taken that no droplets of water above go untreated. Stir the water enough that everything in the container is treated.  Care should also be taken that the drinking mouthpiece is not contaminated with untreated water.

This unit is electronic, and like all electronics is prone to failure, but no issues were reported even while taking it mountain biking over many months.Though, in case of nuclear attacks, an EMP could damage all computer chips, so carry a water filter if you’re looking to be Mr Armageddon.
  Weight: 103g/3.6 oz. with batteries
  Size: 6.1in. x 1.5in. x 1.0in.
  Battery: Uses two CR123 batteries (included)
  Battery life: Disposable – 100 1/2L treatments; Rechargeable -- 40-50 1/2L treatment
  UV Lamp Life: 8,000 treatments 
Travel Case: YES    

One downfall of the item is that replacing the batteries can get expensive if your not using rechargeable.  I just dropped $15 on a pair of Duracell batteries.  I should get up to 100 0.5 Liter treatments out of that.
Note that when using batteries get the 900Ma, not the 600's which do not work very long.  Any name brand should be fine.
I have read other reviews since and noticed some report that the battery runs dead while inside the unit - even not being used, so I keep a piece of heavy paper between the battery and the contact.  I used to just run the battery upside down, but would forget that I did that between trips, so hoping I notice the paper if I should forget again.

Oct 28, 2012.
I'm still using the SteriPen and very happy with it.  I just got back from an overnighter bike trip in NW Georgia.  It is dry and most of the streams are either dried up or near stagnant.  I had to use a barely flowing stream twice, and a river once.  Typically I avoid rivers in favor of mountain streams since rivers could contain run-off from homes or factories that contain pollutants not filtered out or affected by the SteriPen.

In the middle of the route was a high mountain spring running generously so I filled up there and enjoyed mountain clean water.

The SteriPen continues to be easy to use and is a must have for my riding, even on day trips.
As mentioned above, the UV light does not penetrate the water surface, so droplets above the surface could go untreated.  I simply fill the bottle enough and when treating the water dip the SteriPen inside the bottle enough that the water over-flows, thus negating any chance of untreated droplets.

I keep SteriPen strapped to my back pack strap where it is easy to access.  I'm still on the original batteries, though I carry spares with me.  

On the downside (updated March, 2014), this uses disposable batteries, which become a pain after a while.  The batteries are 3 volt, but quality new ones register at about 3.6 volts.  If the battery charge drops below 3.2 volts the Steri Pen will not function.  Beware of internet batteries out of the package sold as new, 3 volts is not a new battery.

If you want a Steri Pen get one with a rechargeable battery through usb so you can leave each time with a full charge, and if needed just use an external charger on extended trips away from electricity.

The CR123 batteries used are not available as rechargeable from name-brand battery makers.