Re: Before I embed a DS10A, any tips...?

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Jack Edin" <nospam@xxxxxxxxxxxxxxxxxx> wrote in

<stuff snipped>

> How MUCH long life over a fresh pair of Duracell alkalines?

Longer life, yes, but the big plus is superior cold weather performance.  I
would bet it gets cold enough in the NW USA at least two or three times a
year to knock your alkalines off-line.  They just don't perform well in the
cold, especially when they have been in service for a while.  A standalone
mailbox gets "cold soaked" very quickly.  If you were in Florida or
California, alkalines would probably do.  But not Oregon.

If your alkalines go offline you'll also have to reprogram and fuss with the
box and brittle plastic and bare fingers when it's very, very cold to find
out why it stopped working, probably during the very time it would be of the
most use.  Falling on the ice fiddling with your mailbox alarm when it fails
or resets due to extreme cold is not what I would consider "top notch" home
automation.  Go the distance.  Spend the $8.  Don't build an exquisite model
sailing ship and then put it in a 2 liter soda bottle.

Mom broke her hip going for the mail on ice.  No need to have such a system
fail during its most critical value period for want of a few bucks in better
batteries.  Marc H. is the resident expert for powering remote observation
station (which is what you're doing, basically).  Maybe he'll have a
suggestion.  I'd use lithium AA cells without hesistation in such a device
in areas where it routinely snows to avoid failure when you need it the
most.

> Is there a chart somewhere?

I'll bet there is!!

> I'd like to see the ratings in miliamp-hours.

Google is your friend.  Tell us what you find.  :-)

Last time I looked at charts, though, lithium was used for anything outdoors
where it routinely gets very, very cold.  They work from -40 degrees to +65
degrees C, IIRC.  I don't think they've improved the basic chemistry of the
alkaline battery so much that anything's changed much since the last time I
looked.  Back then, lithium cells would last 5 times as long as alkalines,
depending on the application.  Today's figures might be different.

Lots of nice charts can be found here:

http://dpfwiw.com/batteries.htm#cold

--
Bobby G.