At any rate, thanks for posting. Since the intervals for the main
batterys and the remote are different, it's easy to get messed up.
As the consequence isn't good, I'm going to make a habit of replacing
the remote every time I replace the main D-cells which is a fairly
long interval.

Actually, you may want to do this the other way around. Duracell D batteries
are living longer and longer - I installed new main batteries in the ELT this
year that expire in 5 years. Whereas the Alkaline remote battery I installed is
supposed to be replaced every 4 years according to ACK. (And I plan to replace
ours every two, to avoid this problem again, especially since there's no
expiration date on the remote battery, and we don't know how long it's been
sitting on the store shelf.)

The problem is, hardly anyone ever sees the expiration sticker on the remote
(and we DON'T want the FAA mandating that we have yet another sticker on the
panel). It's the sticker on the main unit that usually triggers our memory -
and the one mechanics look at.

So it seems the better practice would be to lower the expiration date of your
main batteries to two years, and leave a note on your ELT sticker reminding you
that there is also a battery in the remote that needs replacing.

Hope this helps,

Mike Palmer
Excellence in Ergonomics