I was always told that the NiCad batteries always needed to be
discharged almost completely or they would develop a charging memory
and not charge properly, and this would shorten their life. I know
this was accurate, and covered all nicad cell batteries, cordless
tools, and more.

Now we seem to be seeing a lot of these lithium batteries in
cellphones and other things. should these also be discharged on
occasion, or can they just be charged on a regular basis before they
completely drain?

I'm asking because the lithium battery in my cellphone is getting
weak, and wont hold a charge very long. I have never intentionally
let it totally drain. Most of the time I just plug it in after a days
use. It seems it is now draining from a full charge even with the
phone shut off, (I dont use it often), it will be dead after sitting a
week and not being turned on all during that week.

http://arstechnica.com/gadgets/news/...on-battery.ars

wrote in message ...
I was always told that the NiCad batteries always needed to be
discharged almost completely or they would develop a charging memory
and not charge properly, and this would shorten their life. I know
this was accurate, and covered all nicad cell batteries, cordless
tools, and more.

Now we seem to be seeing a lot of these lithium batteries in
cellphones and other things. should these also be discharged on
occasion, or can they just be charged on a regular basis before they
completely drain?

I'm asking because the lithium battery in my cellphone is getting
weak, and wont hold a charge very long. I have never intentionally
let it totally drain. Most of the time I just plug it in after a days
use. It seems it is now draining from a full charge even with the
phone shut off, (I dont use it often), it will be dead after sitting a
week and not being turned on all during that week.

wrote:
I was always told that the NiCad batteries always needed to be
discharged almost completely or they would develop a charging memory
and not charge properly, and this would shorten their life. I know
this was accurate, and covered all nicad cell batteries, cordless
tools, and more.

Now we seem to be seeing a lot of these lithium batteries in
cellphones and other things. should these also be discharged on
occasion, or can they just be charged on a regular basis before they
completely drain?

I'm asking because the lithium battery in my cellphone is getting
weak, and wont hold a charge very long. I have never intentionally
let it totally drain. Most of the time I just plug it in after a days
use. It seems it is now draining from a full charge even with the
phone shut off, (I dont use it often), it will be dead after sitting a
week and not being turned on all during that week.

I don't know the answer to your question, but I can propose an alternative:

Get a couple of replacement batteries via Ebay. They'll cost you about $4
each (compared to $35 at the Verizon or T-Mobile store) and you'll be good
to go.

wrote:

I was always told that the NiCad batteries always needed to be
discharged almost completely or they would develop a charging memory
and not charge properly, and this would shorten their life.
I know this was accurate, and covered all nicad cell batteries, cordless
tools, and more.

You were told wrong. NiCads and NiMHs have to be deeply discharged
only occasionally, and then never below 1.1V per cell, which causes
damage. Look up "voltage depression". Generally, just charge
normally, don't leave the charger connected all the time, let the
battery run down once in a while, and if a tool is in storage, charge
it every 6 months. Also charge a new battery or a battery that's sat
uncharged for several months for at least 24 hours nonstop before
using it, to equalize all the cells.

Now we seem to be seeing a lot of these lithium batteries in
cellphones and other things. should these also be discharged on
occasion, or can they just be charged on a regular basis before they
completely drain?

I'm asking because the lithium battery in my cellphone is getting
weak, and wont hold a charge very long. I have never intentionally
let it totally drain. Most of the time I just plug it in after a days
use. It seems it is now draining from a full charge even with the
phone shut off, (I dont use it often), it will be dead after sitting a
week and not being turned on all during that week.

BatteryUniversity.com should have the answer to everything, but
lithiums are the opposite of NiCads and NiMHs and don't like to be
discharged much. That website also says to store lithiums at 40% of
full charge, but I don't remember if they want you to discharge them
to 40% or take discharged lithiums and charge them up to 40%. Don't
charge a lithium battery with anything but a charger made specifically
for lithiums or else they can be damaged, won't fully charge, or even
explode (pressure builds up in all sealed cells, even NiCads and
NiMHs).