Battery problem with My cordless Phone - Charging

[lbbs]

I have a cordless Panasonic phone (4-5years old) which has always given me
problems for charging. We let it charge over night and then keep it off
the charger until it dies (NiCd). With a new battery it last 3 days (only
1 hour talk time) and after 3 months of so it only lasts 1 day. Something
wrong with the phone or is it just cheap batteries.

 

[user]

I have a cordless Panasonic phone (4-5years old) which has always given me
problems for charging. We let it charge over night and then keep it off
the charger until it dies (NiCd). With a new battery it last 3 days (only
1 hour talk time) and after 3 months of so it only lasts 1 day. Something
wrong with the phone or is it just cheap batteries.

Well, considering that you're treating the batteries in just
about the worst way possible, it's no wonder they don't last. Keep
the phone on the charger as much as possible. Certainly, keep
it on at night - EVERY night.

Our 5 year old Panasonic is still on its original battery,
and talk time is still well over 3 hours, without the battery
indicator dropping it all.

 

[lbbs]

Everything I have read says to let nicad battery fully drain before charging
again.

 

[Jerry G.]

The normal lifespan of the batteries is about 2 to 3 years. You must charge
them each night, and run them down about once a month to cycle them.

To have optimum battery performance, most of the 2.4 gHz phones will last
about 1.5 to about 2.5 hours of talk time, and about 24 hours of standby
time when used within about 200 feet to the base. Farther distances will
wear the batteries more. The 900 mHz phones will perform about double this
amount of hours.

I change our cordless phone batteries about every 1 1/2 to 2 years to make
sure that I have optimum performance. After about 4 years, if the phone
lasts that long and is still working, I give it away, and buy another one.
If the phone is defective, I retire it, if it cannot be easily serviced.
This way, I am sure to have good reliability.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
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I have a cordless Panasonic phone (4-5years old) which has always given me
problems for charging. We let it charge over night and then keep it off
the charger until it dies (NiCd). With a new battery it last 3 days (only
1 hour talk time) and after 3 months of so it only lasts 1 day. Something
wrong with the phone or is it just cheap batteries.

 

[lbbs]

So what you are saying is that 900MHz phones generally speaking last longer
then the 2.4ghz?

 

[Dave C.]

So what you are saying is that 900MHz phones generally speaking last longer
then the 2.4ghz?

Well, that would make perfect sense as higher frequencies require more power
to produce at the same levels. Thus, if you want the same range on a 2.4G
model, it will use more power than a similar 900MHz model. But only when
it's in use, of course. So standby time should be the same. -Dave

 

[Dave Cole]

Everything I have read says to let nicad battery fully drain before charging
again.

I did alot of reading about batteries and charging lately, and I think the
rule for NiCd is one volt/cell in an assembled battery; any lower and you
risk reverse charging one or more of the weakest cells, thereby permanently
ruining those cells (evidently not a problem w/ single cells, or if you
discharge *each* cell of a battery individually). One good place to look is
www.repairfaq.org/ELE/F_Battery_info.html.
HTH
Dave Cole

 

[Brian Berrigan]

The normal lifespan of the batteries is about 2 to 3 years. You must charge
them each night, and run them down about once a month to cycle them.

I don't think so! I'm an experienced ham and electronic tech, so i
wondered why most of my own and friends cordless batteries were NOT
living up to advertised lives. It turns out that to save a few pennies
the manufacturers have installed cheap, lousy chargers which if left on
every night will seriously overcharge the nicad pack and soon kill the
battery. They badly need a 'smart' charger circuit which will reduce
charging rate to a wee trickle charge once the battery has recovered.

If the phone battery feels hot after an overnight charge, you've
probably done a fair bit of damage already, which you can verify by
measuring the charge current and the hours it has been flowing. I only
charge my phone when it shows a 'weak' or almost dead battery, and they
last a much longer time if only charged (well) when really needed. It
is not difficult to add a few charger components, which cut off most all
current once a preset charge voltage in the battery has been reached. BB