Batteries for low temperatures

[dickm]

The outdoor temperature/rain/windspeed unit on the weather station in the garden stops working when temperature drops near or below freezing (any time after 1 July up here!). It seems to be down to low battery voltage; currently the unit has two fresh Duracell Professional Alkaline AA batteries. Are there any battery makes/types that are less temperature sensitive?

 

[Harbo]

I use Duracell in my weather station, it has recorded -11 once in the past.
Never had any problems with batteries.

Rod

 

[Eric The Viking]

Sadly, there's probably little you can do other than divert some of the power to warming the batteries. Most really cold-weather kit does it that way - military, vehicles, movie industry, etc.

You might use a bigger battery compartment, well insulated, with a reasonably high value resistor in it as a small heater, possibly with some sort of frost-stat circuit. Can you get bell wire to it from an outbuilding? Any protection from the elements you can give the batteries will help enormously.

There's no easy fix though. I was reminded of this watching an excellent BBC programme on the two NASA Voyager probes a few nights ago. They have a small nuclear power source, but even that isn't enough to work in the cold of interstellar space. Both Voyagers are still functioning, thirty-five years post-launch, but the mission controllers are having to shut down modules permanently, one after another, in order to preserve power for remaining systems.

Happily yours isn't quite as intractable a problem.

E.

 

[maltrout512]

Have a look here. Not read how much etc.

http://www.lndcell.com/pro05.htm

 

[Racers]

Hi, Dick

How about running a cable to the station and placing the batterys indoors?

Pete

 

[dickm]

Thanks for the suggestions, guys. I like the sound of the low temp batteries (especially the "interesting" english!) as it's difficult, but not impossible, to action the other suggestions. The key difficulty is that the station sits in an area with garden traffic on all sides, so any wire would need either to be buried (and that's a Kango job - we are on granite ) or strung up high, which would be a bit of an eyesore. Can't really insulate or heat the unit, as the temperature sensor is in the box that collates the information, so it has to be at ambient.
As it's only there for interest (though useful to know how many layers to put on before going to get the paper) it's not worth spending a lot, and of course, it's possible that the problem is with the unit itself, not the batteries, but low temp batteries would at least confirm/deny that possibility.
I see some Googling coming on.

 

[mind_the_goat]

The lower voltage would likely reduce the power of the transmitter hence the effect would depend on how far it was from the receiver. I get a similar problem with mine. Can you move the receiver ?

 

[dickm]

Thanks, goat-keeper(!). Didn't seem to make a difference moving the receiver nearer; it seems as if the whole unit shuts down in cold weather. Will keep trying different batteries and hope that sorts it.
Out of interest, are rechargeables more, or less temperature sensitive than standard alkaline ones?