Lithium Batteries and Avalanche Beacons

A question that has come up recently is are these new high capacity Lithium AA cells good for my avalanche beacon? The motivation for using Lithium cells is that they are designed for electronic equipment (such as digital cameras) and resist cold much better than Alkaline batteries.

However all the manufacturers are very strict about using only Alkaline batteries in their avalanche beacons. This is because the circuitry which detects how much battery life remains is tuned for this kind of cell. The capacity of Alkalines degrades gracefully whereas Lithium (and rechargeable cells) have a relatively flat discharge curve. One minute your beacon is saying 99% full, the next it is on zero.

Avalanche transceivers have relatively low power requirements on transmit. With a full set of batteries they will go at least 200 hours and some will continue another 20 or so hours even when the display shows zero battery life. In search mode power requirements are much higher and a beacon with flat batteries may not work for very long and this is where Lithium and Rechargeable batteries could cause problems. Given that the average skier will only change batteries a couple of times in a season going Lithium or any other type of battery other than that recommended by the manufacturer seems like a bad idea.

Some points to remember:
* Test your beacon’s range on flatish batteries, this can show up problems with transmit power which are not evident on full power.
* Remember to change batteries before their indicated life drops below 50%.
* Sizes vary, check that the brand you buy cannot shake loose. Negative and positive terminals should be proud of the casing and covered by insulation at the edges. Use a known brand such as Duracell, or EveryReady. Avoid no-name Chinese batteries.
* Wear your beacon close to your body to keep the batteries warm and avoid it being ripped off your body in the event of an avalanche if you have removed your shell layer.
* Remove batteries at the end of the season for storage.
* Recycle old batteries – they are often good for portable radios or other devices before they are fully discharged.

More information: Battery problems with avalanche transceivers