Ortovox M1 and M2 battery problems

[Thinker]

This is from an email list I'm on. I don't really know it's date or true origin, but here it is:

 

The following message came from the US Forest Service National Avalanche Center via the Mountain Washington Avalanche Center (NH) regarding battery-size issues for the Ortovox M2 avalanche rescue transceiver.

The M2 may shut off after incurring a moderate blow. The problem has to do with battery dimensions and not the transceiver. The gist of the following message is that AA batteries vary in size depending upon brand, and smaller-sized AA batteries can shift about causing the transceiver to shut off. To prevent a potentially serious consequence M2 users should use "the most robust AA you can find that is wide, long, and has large terminal ends." For more details, please see the message below.

 

Dale Atkins

Colorado Avalanche Information Center

Subject: AA batteries and Ortovox M2 shutdown.

 

You guys might find this interesting and alarming. Excuse this memo if this is already common knowledge, but I have not heard anything about this Ortovox M2 problem. Please pass this along through your networks so we can get the word about this concern. I caught wind that a couple of our

local guides were having problems with their M2 shutting off when the unit took anything more than a moderate knock, such as striking it in your palm.

 

Initially we thought it was the same problem the M1's had with too much slop in the battery compartment, which Ortovox fixed with the M2. They dealt with his issue by increasing the size of the battery pressure tabs on the

inside of the compartment door. 3 of us use M2's so we tried to duplicate the problem. We could get the batteries to shift, but no where near enough to shut off the unit. I was able to get hold of one of the guide's M2 and sure

enough we got the unit to shut off. After some trouble shooting it came down to the specific size of the batteries. After getting 6 or 7 different manufactured AA batteries side by side they were all a bit different in

size. The largest and the smallest were actually quite substantial. The other issue was the height of the + (positive) nub on the top of the battery as well as the - (negative) contact on the bottom. The best battery for

the M2, of the ones we looked at, was the Duracell Coppertop due to it's large diameter and longer length. The negative terminal also protrudes from the bottom while many are either flush or indented. The M2 compartment

tolerances are so tight that batteries 1mm shorter or thinner at times was enough to make a difference to shut off the unit. I was able to shut the M2 down with no trouble with more than one manufactured battery. The

original problem battery was an Energizer alkaline and one of the smallest batteries was the GSA contracted Kodak alkaline AA that many government employees might be using. I never gave much thought to the size changing from battery

to battery, but in this application the consequence could be substantial.

 

I have some additional thoughts about exactly why and how the small batteries fail. Folks can call me if they want the long-winded version. The short of it is use the most robust AA you can find that is wide, long, and has large terminal ends.

 

Chris Christopher P. Joosen

Lead Snow Ranger/Dispersed Recreation Supervisor Director

Mount Washington Avalanche Center White Mountain National Forest

[chris]

This was also in the last issue of Off Piste...