"Roger Long" wrote in
:

I'm pretty impressed with the SPOT beacon battery life. It's still
running on the first set of two AA Lithium's I put in when I bought it
back in May. This includes:

All the testing and playing after purchase.
Running it for nearly every daysail, 4 - 6 a week. This was great
because I was often alone and people didn't have to bug me on the cell
phone to find out if I was headed in for dinner.
8 - 12 hours a day on our 9 day cruise downeast.
10 - 14 hours a day on the recent 8 day Rachel Carson delivery.

I'm wondering just how much life is left after a summer of fairly
heavy use so I've set up a new page and started it running on the
window sill. You can watch it die he

http://share.findmespot.com/shared/gogl.jsp?glId=
0VC8x0r9JUgIniche7ZeYW
Ua0SLl40PnT

This is starting at 3:30 on election day. It may be a little while
before fixes show up.


Is this what they are?!
http://www.batterybank.net/digital/master/aalith.html

1.5V 2.9Ah...very dense, non-rechargeable and a 10 year shelf life easy.
4-pack is less than $8 from there.

Why is everyone giving Spot so much money for them?? That's crazy!

By the way, these are GREAT walkie talkie batteries for marine walkies,
too! With a 10 year shelf life and such a high Ah rating, you get both
great storage life for standby walkies and great runtime when you pull
them off the shelf after sitting for a few years.

Do NOT confuse these true Lithium-Iron Disulphide batteries with cheap
crap batteries with the word Lithium on them at your local electronic
store. Anyone can use Lithium as a trade name, and do. There are lines
of plain Alkaline batteries with "Lithium" on the label....which, I
think, needs to be prosecuted.

"This Lithium AA battery is disposable and is for one time use only (Not
Rechargable) . It is a disposable Lithium Iron Disulphide chemistry
which should not be confused with rechargeable Lithium-Ion technology.
There is no such thing as a rechargeable AA Li-ion battery available in
the marketplace."

The reason for this last statement is that Li-Ion and Li-Polymer
batteries each have a built-in charge state IC that makes sure they are
not discharged past 50%, which destroys them, and makes sure they are
not overcharged, which causes them to explode....like Sony laptop
batteries do. Li-Ion batteries all have THREE contacts. The IC has its
own output to the device charging circuit to shut down the charge when
full and make the device indicate the full charge somehow.

"Larry" wrote

Is this what they are?!
http://www.batterybank.net/digital/master/aalith.html


Yup, that's them.

I just realized that the SPOT probably doesn't have a GPS in it but works
like the cell phone GPS. All it does in tracking mode is wake up ever 10
minutes and transmit a short series of numbers to the satellite. One is the
unit identifier and the other is the raw GPS data received. This little
burst probably takes a millisecond. The rest of the time, it's just
sleeping unless someone pushes one of the buttons. All the position
processing is done on the big computer back in Texas. Everything except the
unit ID, is input into the website by the user so does not need to be
transmitted.

--
Roger Long

"Roger Long" wrote in
:

I just realized that the SPOT probably doesn't have a GPS in it but
works like the cell phone GPS. All it does in tracking mode is wake
up ever 10 minutes and transmit a short series of numbers to the
satellite. One is the unit identifier and the other is the raw GPS
data received. This little burst probably takes a millisecond. The
rest of the time, it's just sleeping unless someone pushes one of the
buttons. All the position processing is done on the big computer back
in Texas. Everything except the unit ID, is input into the website by
the user so does not need to be transmitted.


It has a full GPS chipset in it. GPS isn't like the old receivers, now.
Once they have a fix initially, they resync in milliseconds as soon as the
3rd bird completes its statement. It's quite fast.

The GPS won't be far from its last position, so it doesn't have to do a
bunch of searching when it's in tracking mode. That's why the battery is
so long running. Then it goes back to sleep.