# Useful Transceiver Checklist Mnemonic



## Rip154 (Sep 23, 2017)

Don't get the last 2 points, aren't they a bit similar?


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## caboholic (Dec 24, 2018)

No, they’re opposite. During the “S” stage the leader is on transmit and he walks by each person in the group. While they’re doing that, each person checks their transceiver to see that the number displayed is going down. 

During the “T” stage the roles are reversed and the leader checks their own beacon to see if they’re properly seeking (or that everyone is transmitting properly).


Sent from my iPhone using Tapatalk


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## Rip154 (Sep 23, 2017)

Ah like that. Guess it's more of a general funtioncheck, or like standard for guided groups. Usually do the transmit check out before we enter terrain/start riding, but then the rest is kinda meh since your already out there anyways.


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## killclimbz (Aug 10, 2007)

Batteries at 50%? I would say under 70%. Depending on how cold it is, you can have a significant drop over the course of a day. Most avy pros I know, and I know a lot of them, replace their batteries when they hit that 70% zone. Definitely replace with alkalines. Other than my 50% gripe, this is a very solid checklist. Great post.


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## Rip154 (Sep 23, 2017)

Mine were at 28 from last season when I changed. Not bad for being stored 7 months. When you think about it, kinda sucks to run out of batteries in the middle of a search, so more is better. Plus it gives rescue more time to dig out your carcass.


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## neni (Dec 24, 2012)

killclimbz said:


> Batteries at 50%? I would say under 70%. Depending on how cold it is, you can have a significant drop over the course of a day. Most avy pros I know, and I know a lot of them, replace their batteries when they hit that 70% zone. Definitely replace with alkalines. Other than my 50% gripe, this is a very solid checklist. Great post.


Interesting. May be beacon dependent? Here, we get told by guides/at courses to replace at 30%; Mammut Barryvox is the mainly used I think. (Mammut Barryvox manual even sais at 20%.)

Haven't yet checked how battery draining varies searching in different temperatures... will do in future to get a feel.


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## f00bar (Mar 6, 2014)

Alkalines seem like a terrible choice for batteries as they are water based.

*Non rechargable* lithiums take almost no hit until you get under -20C. In a cold situation I would think they easily become more cost effective than an alkaline over their life.

Though thinking on it I guess the disadvantage is that they hold their voltage until the very end making it harder to tell how drained they are.


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## deagol (Mar 26, 2014)

I think the thing about alkaline is you see their drop-off so you don't get surprised with a sudden drop-off.


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## killclimbz (Aug 10, 2007)

Do not use lithium batteries. Like deagol said, they are fine and then all of the sudden they just die. Alkalines have a more dependable output. 

As far as what your beacon is reading. Yes, I have gone out with 50%. I got back from the day and my reading was in the 30's. I have also left my beacon on for over a week with full batteries and was down to like 40%. The biggest question is, how much are you pushing it when you are 50 or under? Going out for the day, probably okay. Keep in mind, when you are in search mode, that is the biggest drain on the battery. You beacon is in an active mode and that uses more energy. Versus when you are in transmit, which is a passive mode and has low energy use. 

Just something to keep in mind. Batteries are cheap. I use the exchanged ones for headlamps, and that sort of thing. I leave those decisions to you, just giving my opinion fwiw.


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## f00bar (Mar 6, 2014)

Alkalines are the opposite of dependable output in cold temperatures. Which is why it took a week to drop 60% at room temp but you would think about changing it out at 40% before going out for a day.

What they give is the convenience of letting you know some sort of capacity left at any moment. However that doesn't tell you where it'll be at any point after that given a constant draw at an unknown temperature. In fact I would argue that it is completely misleading which is why you change it out at a ballpark number.

With a lithium you take the oil change approach. After x hours of usage you change it. It's a back of the napkin calculation that in reality is way more accurate than % charge left indicator that can't see into the future. Replace battery after X hours usage and I would imagine that the beacons could or do have some sort of time counter just like my lawn tractor does for keeping track of hours running since last oil change.

Of course with dealing with the public and safety I can understand how you(the industry) can prefer the simpler solution even if it isn't the ideal. People understand %. And adding a new player to the field can add confusion which is the last thing you want, even if there is a better performing option.

Not trying to start a big debate or say one is wrong the other right. Just my opinion.


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## killclimbz (Aug 10, 2007)

Lithiums are a better battery. Just not for beacon use. At least yet. All manufacturers only promise performance using alkalines. I believe there is one beacon now that uses a rechargeable battery and that there is some experimenting going on with designs for use with Lithium batteries. So the dynamics will probably change given time.


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## deagol (Mar 26, 2014)

Another thing to include in the discussion RE cold weather use. That may not be as big an issue as you think because beacons are worn under your (outermost) clothes and therefore are not exposed directly to the cold outside air, but instead are under at least your outermost layer. So there is some body heat keeping the beacon warm and protecting it from the cold.


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## killclimbz (Aug 10, 2007)

Just going off experience regarding the cold. There is a drop off. I see it more during the cold months, than say a nice spring tour. Either way, the power level at the start of the day is not the same at the end of the day. For example, I was at 97% at the start of the day at Monarch Pass, when I got back to the truck 81% was my reading. Turn on my beacon now and it's 97% again. Seen this with BCA's. Did not look at that when I had to use a Barryovox for a cat trip. I've also had bigger swings than that. Generally a bigger swing as the battery has less of a charge is what I seem to see. I guess since we've gone down this rabbit hole, I'll have to pay more attention to it. Generally I have just swapped out the batteries.


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## f00bar (Mar 6, 2014)

Basically % charge for alkalines is determined from voltage ranging from 1.5v for 100% -1.1v for 0%. As the zinc in the anode reacts it produces electrons over time as the zinc depletes the voltage drops. This is normal behavior.

However, the electrolyte is water based so starts to crystalize under 32F. When this happens the crystals block the flow of electrons from the cathode to anode, reducing the voltage. Warm it up again and voltage is restored.

This is also why some people store alkalines in the freezer. All batteries have a self discharge rate. Freeze them and that is reduced. Ironically some these people have thrown out perfectly good batteries by grabbing it from the freezer and checking the voltage before it's warmed up.


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## deagol (Mar 26, 2014)

f00bar said:


> Basically % charge for alkalines is determined from voltage ranging from 1.5v for 100% -1.1v for 0%. As the zinc in the anode reacts it produces electrons over time as the zinc depletes the voltage drops. This is normal behavior.
> 
> However, the electrolyte is water based so starts to crystalize under 32F. When this happens the crystals block the flow of electrons from the cathode to anode, reducing the voltage. Warm it up again and voltage is restored.
> 
> This is also why some people store alkalines in the freezer. All batteries have a self discharge rate. Freeze them and that is reduced. Ironically some these people have thrown out perfectly good batteries by grabbing it from the freezer and checking the voltage before it's warmed up.


This bit of information may be really relevant for the Gopro battery cold weather discussion on that other thread....


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## deagol (Mar 26, 2014)

f00bar said:


> Alkalines seem like a terrible choice for batteries as they are water based.
> 
> *Non rechargable* lithiums take almost no hit until you get under -20C. In a cold situation I would think they easily become more cost effective than an alkaline over their life.
> 
> Though thinking on it I guess the disadvantage is that they hold their voltage until the very end making it harder to tell how drained they are.


I use radios in the BC to communicate with partners and the batteries (standard alkaline) definitely don't last long in the cold. I wonder if using Lithium batteries in the radios would be a good idea ?


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