Battery was new in the package when I put it in. Was not a "name brand" like Duracell, rather a "surefire" brand (they make tactical flashlights, so I thought that would be a good way to go). Don't remember what the voltage was when I got it and tested it on a voltmeter, but I believe it was around 3.25 volts. Solar panel is shade free all day and faces due south. Only problem is, it's up on my peaked roof, which is a bit of a pain to get to. When the weather warms up, I will go up there again and replace the battery with a Duracell or Energizer type cell.
The low battery warning message is indeed a warning, however, after that warning was displayed for a few hours (while it was dark outside) the voltage must have dropped pretty fast in the cold and it stopped gathering data (outside temp, wind speed/direction, etc) until the sun came up and hit the solar panel.
Don't bother. The Surefire battery is as good, and likely better, than a Duracell or Energizer. Only others I might even recommend would be Sanyo and Battery Station's house brand. FYI, you don't need to spend $10 or more per battery either, when you can get good ones for less than $2 each (check out my post
here).
Understood. When you replace the battery, it will be interesting to see what the voltage is - and perhaps you will put it in your freezer for a few hours and then measure the voltage. Different brands respond differently to cold temperatures, of course.
Of course, with the unit mounted where it is, it's possible that there's snow (or bird-whatever) on the solar panel. But a good battery should power it without any sun for more several months.
Bottom line: the behavior that you experienced is unusual. And many of these units are working through very cold (and dark) conditions. So, it's a good guess that your experience is due to the battery.
Let us know what you find out, when the weather improves.
His experience IS unusual, but I disagree that it is the fault of the battery
IF he used a brand new one that wasn't bad for some odd reason. Now, if the solar panel is not providing any power to the ISS, the battery may be getting depleted, but I don't think it should happen quite so quickly either.
The Surefire 123 is the one of the best primary CR123 Lithium batteries on the market, and I say this as someone who has bought literally 3-4
hundred primary Lithium 123 batteries in the past 10 -12 years (and have personally used at least half of them).
I won't buy anything other than Surefire, Battery Station, Sanyo, or Duracell (ordered by my opinion, based off of experience, of best down) for use in my gear based on my personal experience with cheap brands.
Primary Lithium CR123 batteries do quite well in the cold, much better than most chemistries. I'm actually quite surprised Davis provides a Duracell cell with the new Vue units, and not some cheap off brand.