Cell batteries laid dormant for years

I have 3 old Nokia cell phones that sat around for years
(wasn't used much to begin with), and now, they seemingly can't be
recharged at all. Can that happen to old phones?


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› See More: Cell batteries laid dormant for years

Ablang wrote:
> I have 3 old Nokia cell phones that sat around for years
> (wasn't used much to begin with), and now, they seemingly can't be
> recharged at all. Can that happen to old phones?

It can happen to old batteries, yes.


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In message <[email protected]> Ablang
<[email protected]> wrote:

> I have 3 old Nokia cell phones that sat around for years
>(wasn't used much to begin with), and now, they seemingly can't be
>recharged at all. Can that happen to old phones?

If they're LiON and they completely discharged, they're 100% dead.
Since LiON batteries self-discharge over time, chances are if they sat
for years, they're toast.


--
Tact is the ability to describe others as they see themselves.

The Apple iPod site recommends charging them up fully and
discharging them at least once a month, even if they're not used.

And they last for only about 400 charge cycles. I wonder if
all Li-Ion batteries behave that way?

>If they're LiON and they completely discharged, they're 100% dead.
>Since LiON batteries self-discharge over time, chances are if they sat
>for years, they're toast.


===
"Until last October, Christ had a very limited involvement in my life. I believed in God; I just never had to prove I believed. Belief is an absence of proof."
-- Boston Red Sox pitcher Curt Schilling

Ablang wrote:
>
> The Apple iPod site recommends charging them up fully and
> discharging them at least once a month, even if they're not used.
>
> And they last for only about 400 charge cycles. I wonder if
> all Li-Ion batteries behave that way?

Yup.

A charge cycle is a charge cycle, whether it's full, half, or whatever.

Notan

A couple times in the past couple years I thought an SE LI Polymer
battery had died since it wouldn't take a charge. I left it on the
charger for several hours and suddenly it began charging and now works
fine. This was in a back up phone that was in the drawer.
I am a heavy user (1500 - 1500 mo.) and keep my 600 mah battery on
the charger whenever i'm in the car. At home I put it in the charger
if it appears to have less than a 75% charge. This has been going on
for 2.5 years or more and just recently seem to be losing a very little
available talk time. I would guess there are at least 2 or 3 "recharges
to full" a day. Total over the years would be well over 2000! I almost
never let it get below 1/2 full.
I have read elsewhere it is not the total number of charges, but the
total of how much juice you have added over time. Eg. Recharge to full
ten times when it is 90% full is equal to one recharge from when the
battery is at 0%.

...mike


Notan Wrote:
> Ablang wrote:-
>
> The Apple iPod site recommends charging them up fully and
> discharging them at least once a month, even if they're not used.
>
> And they last for only about 400 charge cycles. I wonder if
> all Li-Ion batteries behave that way?-
>
> Yup.
>
> A charge cycle is a charge cycle, whether it's full, half, or
> whatever.
>
> Notan


--
snidely

In message <[email protected]> Notan <[email protected]>
wrote:

>Ablang wrote:
>>
>> The Apple iPod site recommends charging them up fully and
>> discharging them at least once a month, even if they're not used.
>>
>> And they last for only about 400 charge cycles. I wonder if
>> all Li-Ion batteries behave that way?
>
>Yup.
>
>A charge cycle is a charge cycle, whether it's full, half, or whatever.

Most LiON batteries can put out a certain amount of power over their
useful lifetimes. If you can get 100 full discharge*/recharge cycles,
you'll get approximately 200 half discharge/recharge cycles.

There are a couple caveats.

1) Heat. LiON batteries get hot when they charge. Heat also damages
them. Typically the faster and the longer they're charging, the hotter
they get, so a full recharge is harder on the battery then recharging it
from 50%. However, some batteries heat up really fast, so in that case,
two half charges might be harder on it then one full charge. This
depends on the design of the battery more then anything else.

2) "Full Discharge" -- You should never fully discharge a LiON battery,
if you do, it's toast. However, most LiON batteries (and/or the devices
that use them) are smart enough to report the battery as dead and stop
working around 10%-15% of the batteries capacity. In many cases this
circuitry is part of the battery itself and the battery simply ceases to
function.

It's also worth noting that this circuitry cannot prevent the battery
from self-discharging, so you shouldn't store a LiON when it appears
completely dead (even if it's at the artificial "dead" cutoff and the
battery isn't dead enough to cause damage) since it will naturally drain
down.




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