What to do when the light finally dims

Unless you do plenty of night hiking, quite a few years may have passed. The lithium thionyl chloride AA cell that powers the burrlight is quite happy being stored for ten years. If there has been a long period of no use, the light may be dimmer when you switch it on, and begin brightening after a few hours of illumination. If you do notice this, try and use it a little more often!

Assuming the battery is really dying, rather than just dropped off to sleep, what to do depends on where you are, whether you have any constructional skills, and above all on the state of the burrlight case.

If the torch body is well battered by hard use, since the cost of the cell accounts for a significant fraction of the cost of the torch, throw away your 'old friend', and buy a new one. The same advice applies if you have more money than time, whatever the state of the case.

If the torch is still physically in good condition, you can send it back to Breck Bowles Development to be checked out and have a new battery fitted. We will replace the battery, probably replace the end caps, and post it back to you. Your total cost, including all postage, will be about half as much as you paid for the original burrlight, unless of course, you live in Greenland. E-mail us for details, or with any other problems you may be having.

You may want to 'fix it yourself', or get a skilled friend, or electronics serviceman to do so. Unlike most manufacturers, we encourage people to 'monkey with our products', but please note this warning: the instructions assume you are skilled, capable and awake. We will not be liable for injuries sustained as a result of following these instructions, or for damage to the burrlight.

The lithium thionyl chloride AA cell is made by Saft, of France, who are one of the best battery makers in the world. They also have a factory in the US. This cell has a thin flexible strip for making solder connections at each end of the cell. The current price is around fifteen Australian Dollars. Jaycar Electronics sell something similar, but with wire ends. The Jaycar cell, according to our tests, is electrically not as good, and the wire-soldered ends will not fit properly into the burrlight case. In addition, the Jaycar cell costs a good deal more. Don't buy it.

You want a SAFT LS14500 CNR lithium thionyl chloride cell.

The Australian suppliers are currently

Battery Specialities (Vic) Pty Ltd
240, Boundary Road
Vic 3195

tel 03 9587 2101 fax 03 9587 0866

This company sells both to Trade and the Public.

In most countries, an Internet search via www.google.com for "LS14500" should turn up a supplier.

Dismantling the burrlight

First remove both end caps. You need a craft knife with a new blade, or a very sharp hollow-ground penknife blade. Slide the blade into the thin groove where one end cap meets the tube body of the burrlight, and press down firmly. The end cap will move out just a fraction as the blade forces its way in, without cutting either the burrlight tube or the end cap. Turn the tube round a bit, press down again on the blade and repeat until the cap is a fraction out all the way round. Change to a sharp knife with a thicker blade and repeat. Change to a blunt non-serrated cutlery knife, and repeat. The cap should now be far enough out to insert the back of the cutlery knife and force it in. Never use the back of a penknife blade, for obvious reasons. Once the cap is out this far, you can wiggle the back of the cutlery knife to force it farther, and do the last removal with your fingers. Repeat on the other cap. You should be able to remove both caps undamaged. Note that the two wires at the LED end are long, and will have to be carefully arranged when you reassemble, to prevent them obstructing anything.

With the LED end cap out, give the wire going to the positive terminal of the cell a gentle pull to lift the solder tag off the supporting cork. Note how the wire is soldered down, then unsolder it from the tag using a medium size (not tiny) soldering iron running cooler than usual. With both caps out you can now push with your fingertip or a small plastic screwdriver handle on the positive terminal of the cell, until it has moved about half an inch into the cork. The brings the other cell end out of the burrlight tube so the joint there can be also unsoldered. Before you unsolder, again note how the wire lies, for reassembly.

You can now pull the cell right out of the mounting cork by the negative end, and discard it. Push in the new cell about half an inch into the cork, and resolder the negative end to the wire. Continue pushing until the top of the positive terminal is flush with the holding cork top and resolder to the top wire, being sure, if you did not check before, that the top solder tag points in the opposite direction to the LED window. Rearrange the top wires, and push both end caps as far in as you can by hand. The magnet strip is still in position on the outside of the burrlight body, so check the torch is still switching on as it should. If not you could have reverse battery polarity, or the main mounting cork inside has rotated so the reed switch no longer aligns with the black/white boundary. The LED cap has to be very carefully placed so the LED is pointing out of the centreline of the window.

Final pushing in of the end caps can be done in a large bench vice, or with a very big G-clamp. If you lift weights for a hobby, you can produce enough pressure with the heel of your hand vertically on the end of a cap to push it right in. Applying excess pressure with the vice, after the caps are fully in, can cause damage. Your burrlight should now be good for a few more years.

Contact Details and Specifications

The burrlight is designed, developed, and manufactured by

Breck Bowles Development
4, Cunningham Crescent
Victoria 3810

Phone/Fax +613 5941 4789 overseas 03 5941 4789 local

e-mail breck@techinfo.com.au (or breck@permaflate.com)
website www.permaflate.com


Light weight. The burrlight weighs 45 grams, compared to the more normal weight of 100 grams for a full-spec LED torch.

Sealed construction. This torch may be operated underwater, and repeatedly switched on and off underwater. It is sealed at all times.

It floats. This feature is very handy in lakes, less useful in fast-flowing shallow streams.

Brightness. 5000 millicandelas with a new battery.

Long battery life. 200 hours to half brightness.

Good beam pattern. This torch is designed, and has been used for night hiking in trackless areas. Tree trunks 25 metres away are visible in the beam.

Cold resistance. The Lithium Thionyl Chloride cell used produces half brightness at minus 25 degrees Celsius, or considerably colder than most of us experience outdoors. At these temperatures you are likely to be on snow, where much less light is needed anyway. Normally for extended travel the burrlight fits on your hat, where your head warmth lifts the torch temperature considerably above ambient.

Impact resistance. The burrlight typically fails after being thrown 20 metres in the air, and impacting a stone-chip road surface, one hundred times. A number of causes finally put the light out. Internal damage to the AA cell itself can cut light output drastically, or make it irregular, and soldered wires can tear off after 100 drastic impacts. So far the switch mechanism has not been damaged by impact, and the test switch has survived 600 such impacts. For normal use, where all you are likely to do is drop your torch, it will not go out.

Reliability. All connections, including those to the switch and Lithium cell, are hand soldered. No electronics are used to maintain the light output at constant brightness, until it suddenly fails, so if the light comes on when you test it before leaving on your trip, it will come on when you need it. The switch is a sealed magnetically operated reed switch which you actuate from outside the torch body. The magnet actuator is very low strength, and will not shift a compass needle if the compass is more than 10 cm (4 inches) away from the torch.