View Full Version : Off Topic (Obvously) - strange cordless phone battery problems

06-02-2005, 06:41 PM
Yesterday I took my cordless phone into the lounge and left it there after using it, then I was not bothered to put it back and left it there overnight.

went to use it today - didnt work - so I thought battery must have discharged, now my phone has a place to charge a 2nd battery in the base station, so I took the one out of there and changed it for the other.

Still didn't work - so I checked the voltages of both batteries with multimeter - 2.69v (meant to be 3.6v)

Left them both to charge all day but still neither work - base station LEDs indicate charging, but neither battery seems to go past 2.69v

So then I connected a power adaptor set to 3v to the phone - and it turned on - which leads me to suspect the batteries...

Is it possible that both have died on the same day? or is it something more mysterious?

06-02-2005, 06:54 PM
Ours gets left all over the house (my daughter used to return it days later when it went flat).

Try turning it off at the wall, waiting a few minutes and turning it back on. Often works with computers...

Oh, and do the same with the phone jack.

06-02-2005, 07:19 PM
I confirm Mercury's suggestion. I've had the same problem and the only thing which worked was disconnecting the phone completely for a few moments. From power and line. Reset itself no worries. Worth a try.

06-02-2005, 08:05 PM
No change after that, except battery voltage for the cordless unit is now 2.71v, and the base station is 2.76v - Possibly the disconnection thing worked, but now It needs charging overnight?

06-02-2005, 09:09 PM
Measure the voltage the charger outputs. If it is less than 3.6v (more likely around 4.8v without a load) then the charger is broken. Not to worry, just grab a 3.6 - 5.0v power supply and use that to charge. Crude, yes I know.

06-02-2005, 09:47 PM
Voltage for "spare charge" battery charger on base station is 14.10v

voltage for handset charger is 9.51v

06-02-2005, 10:00 PM
This sounds like a Panasonic flip phone? They are the ones that I am aware of that have the spare battery in the master station.

The 2.69 volts sound ominously like one cell in the pack (3 button cell pack) has died, in that case. In both batteries.

This is common if they are 2+ years old, expected if 3+ years old.

The charger voltage is much higher, as it is current limited to protect the cells.

Sounds like an expensive replacement. Jaycar used to have the units at a competitive price.

06-02-2005, 10:15 PM
I don't suppose it is the type of battery that retains memory? If so maybe you need to recondition the battery by continual charging/discharging (unless it is too late).

Do you have a manual with it?

<...says she heading off downstairs to read manual and possibly take phone off charger...>

06-02-2005, 10:44 PM
you are correct, it is a panasonic flip-phone, KX-T3000 BA, and yes i do have the manual... although it doesn't have much useful info on the batteries.

I bought the two batteries that are here at the moment new from the dick-smith electronics store in henderson (before it moved to the mall)

I can't remember when this was, but It seems a long time ago so I expect they have died, as godfather said - but I shall check the receipt

(I will still have it somewhere here as I have kept every single one) :eek:

so, just checked through my stack of receipts, and the date for this particular one is 24/11/01, so they've been going for just over 3 years.

I shall probably get a new one tomorrow and see what happens...