On Tue, 14 Jan 2014 23:57:25 -0500, Tony Matt
wrote:

On 01/07/2014 10:48 PM, Danny D'Amico wrote:
When I put the batteries back, I noticed that all five handsets said to
"Charge for 7 Hours" ...
[...]
So, something fishy is going on ... with the charge message on the
handsets ... but I don't know what yet.

Been there, done that, should have posted sooner. These/some Panasonic
cordless handsets display a "Charge for 7 hours" message (and a single
bar on the battery gauge) whenever batteries are installed, regardless
of the state-of-charge.

Details:

Last spring I attempted to set up a used KX-TG9341S system and got this
message on all of the handsets. Old batteries, new batteries, Panasonic
batteries, externally charged batteries, didn't matter (other than
alkaline cells, which it detected: "Wrong battery type"). Measured
voltages, currents, took apart a handset to look for damaged components,
double checked that full battery voltage was actually getting to the
PCB. Googled it, read a bunch of head-scratching, generic battery
advice, and speculation. Got frustrated and moved on to other projects.

A few months later I saw some of the Panasonic NiMH cells at the local
recycling center and decided to take another run at it. I charged
(externally) all of the cells and tested them. Then I got another idea
- I don't normally use AAA NiMH cells, but use lots of AA cells, so
jumpered over a pair of known-good, freshly charged AA cells to the
battery terminals of one of the handsets. Still got the 7 hour message.
That seals it - it's not the batteries. I picked the best six
Panasonic cells, let the handsets go through their 7 hour charge cycle,
and have been using the system ever since.

Panasonic apparently decided to override the charge sense/termination
circuitry with the 7 hour timer when batteries are installed in order to
reduce product returns (from customers who neglect to read the fine
manual and discover that their brand-new handsets and batteries don't
work right away). I did find some weak cells over time, but that's
unrelated to the 7 hour message.

Recommendations:

1. If you put charged cells into the handset, ignore the message and
leave the handset out of the charger for a few days (while using it, of
course). Otherwise, the batteries will be overcharged by the forced
7-hour 'initial' charge.

2. Test for good cells in the handset by trying the speaker phone
option. A weak cell will result in a power cycle (no audio, blank
display, then display with no backlight). If both cells are weak, it
will power cycle when the backlight comes on (i.e. whenever a button is
pressed). Check the cells under load with a meter to determine if one
cell has dropped out, or they are both at low charge. Keep pairs of
cells matched wrt state-of-charge.

3. Look elsewhere for the solution to your link issue.

Good Luck,
Tony Matt
If the power to the master is disrupted while the remotes are not on
charge it is possible for the remote to loose connection to the base
on SOME Panasonic phones. Mine are KXT5433 5.8ghz units and it has
happened to me. Don't know about DECT