sanramonrover wrote:So charlie, I'm not sure I understand your last post.
.... I'm a big fan of lithiums, but as I mentioned earlier, the distance between transmitter and receiver has far more impact, and really drives what voltage you need from the batteries.
Is that to say that the further your receiver from the transmitter, the more battery drain? I'd guess the transmitter uses the same power no matter where the receiver is.
Or do you mean that if you can use a (slightly) higher voltage on the outdoor unit, you will get more distance to the reciever, or at least less dropped connection?
Curious.
sorry if I wasn't clear. The signal strength of the transmitter is directly proportional to battery voltage. So let's say you have a new set of batteries. The range will be "X". Your receiver will work happily within any distance from "0" feet/meters to "X" feet/meters. As the battery drains, "X" gets smaller. So if your receiver is very close to the transmitter, "X" (or battery voltage) can get very small before you lose the signal - maybe taking 2 or 3 years. If your receiver is very close to "X" then a small drop in voltage and you are out of range - maybe only a couple weeks.
The battery voltage droops as it discharges - different curves for different technologies. The weather station uses so little power, that the battery self discharge actually dominates. If transmitter and receiver are relatively close to each other without a lot of stuff in between (i.e. the voltage can get pretty low before loss of signal happens), then "ni-cads" will die in a few weeks/months, "heavy duty" will die in a year or so, "alkaline" in a couple years and "lithium" in a couple decades.
If you are on the extreme edge of the range, all technologies will die quickly and you'll be posting about how terribly the beast eats batteries no matter which kind you buy!
As to question 2 - yes a slight increase in voltage seems to give you a slight increase in range. However it's a short step from better range to tossing it in the trash because you fried it. This is not recommended... you have been warned
) I decided to run a thick 13A cable from the battery box into the loft space and connect a couple of large 1.5v batteries in there. The batteries stay warmer, I don't have to risk life and limb when they run out, and the weather station can't blow away as it's tied to the roof by a thick cable! 