I like that!  $15 seems like a bargain for this item.  I have a smaller
radio shack in/out thermometer in the van, and have the outdoor sensor in
the fridge.  I have just been laying it on the floor between the driver's
door and seat.  I have been thinking about where to mount it, and am
considering just above the driver's door.  I'd like a place that I can see
it while driving or camping with the front curtain in place.  The voltage
measurement is a nice bonus, and per your test, seems pretty accurate.  an
on-off-on toggle switch would be allow it to read from both batteries or be
turned off.
Thanks for the info and write-up on this item.
Edward

At 10:34 PM 8/23/2004, you wrote:
>I was searching for a nice digital thermometer for measuring indoors and
>outdoors temperature for the Westy. I looked thru Oregon Scientific and
>Lacrosse Technology but didn't find one that meet my need. I then found
>this Radio Shack model 63-1039 which is intended for auto use and it
>turned out very nice and has the bonus function of measuring battery
>voltage as well as a cute level indicator. It also have min/max as well
>as ice alert.
>
>Here is the Radio Shack link:
>http://www.radioshack.com/product.asp?catalog_name=CTLG&category_name=CT
>LG_010_004_001_000&product_id=63-1039
>
>This unit is ideal for those who add the aux battery but haven't a way
>to monitor it's level.
>
>If you don't care for the exterior temperature you can use the remote
>temperature for monitor the refrigerator inside temperature.
>
>I have more information on my site including some bench tests I did and
>my planned installation:
>
>http://gipsyflies.home.comcast.net/thermometer.htm
>
>
>
>- Vince
>
>http://gipsyflies.home.comcast.net
>1989 Vanagon GL Camper
>1993 Mazda Miata
>1996 Land Rover Discovery
>2005 Mini Cooper S (almost here)