When do you replace your tranceiver batteries?

But you did say it by posting this. Obviously you have a ways to go.

You too obviously.

I think I recall from my Avy level one that most beacons are designed to work well past 0% --  or probably more accurately, the reported percentage is not the true percentage.

I change at around 60-80%, or before a big trip- with the following context:

I don't throw them away, I rotate them to another use. I have a headlamp or two in the house and use them as a way to use up batteries in non-essential equipment. If my remote control or headlamp dies, I will steal from the beacon, or ski-pack headlamp and put fresh ones in there.

I think I'll start getting new tires and brake pads after 20% use. Maybe I'll sell them on Craigslist.

I change at 80%. I let my batteries go down to 70% once and then tested. I could transmit just fine, but I was not receiving as well as better charged trasceivers. I changed batteries, problem solved.

Tell you what, I always have spare batteries around. If you want to ski with me, and have batteries under 80 %, I'll give you a free set of batteries. Once.

But I might not be home the next time you call!

How is it that you know how much charge is left in your batteries?

I have an older analog transceiver, with no battery indicator on it.

Also, is the use of NiMH inappropriate for only the digital units?

I have used NiMH in my old analog in practice and could see no loss in real performance.  I am aware that these units are designed to function from a source of power with a given voltage, which is admittedly lower in NiMH, but then alkaline, as they loose charge do fall into that range of voltage and therefore they would be expected to function within specs.  I would assume that the internal power supplies of the beacons step the voltages up or down to the proper working voltage for whatever part of the unit requires, such as the signal generator, the amplifiers, the digital displays, etc.  The biggest issue would seem to be the fact that the calibrated battery indicators would see the NiMH as being low on charge.  Certainly disturbing if in fact you rely on the indicator.  I of course do not, I do not have an indicator and therefore simply replace the battery each time.

NiMH batteries have the same or more amp/hr as alkaline.

For those who do have battery meters, how many hours of use (lets say to 80%) do they give you?

So is using NiMH an issue limited to digital beacons, the battery meters or some fundamental problem with fractionally lower voltages of the NiMH?  I know the simple answer is that the manufacturers all say not to use them, but I am looking for a concrete reason.

Alan

One additional point adding to this post, since my analog, in theory and in some practice offered additional transmit and receive range than the digital, what am I sacrificing if I lose 10% range with NiMH?

p. 7:
www.americanavalancheassociation.org/tar/TAR28_4_LoRes.pdf