Discharging rechargable batteries

I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?

wrote in message
ups.com...
I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?


See if there's a battery discharge option in the setup menu on your camera.
Mine has one.

Ron

Look on the bottom of your AA NiMH batteries,
if you do not see the letters stamped, "HR"
Then you may want to purchase a few Energizer
2500 mAh at Sam's, etc.

IMHO, the 2500mAh and the "HR" are very important :-)

I have tried discharging NiMH AAs, without success.
In fact, I believe that it hurts the cause to power cycle them



wrote in message
ups.com...
I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?

There are chargers that will do it for you (do a little Googling). I
simply put mine in my MP3 player, which will take them a lot lower than
my cameras before giving up. I believe CD players and radios are just
fine for that as well. Don't use a flashlight --- it'll take 'em too low
trying to drain every last bit of energy from them. My sense is that a
'full' discharge may be good now and then as long as it isn't too full,
but it really isn't terribly necessary once the batteries are broken in
and you let your camera do its thing. Happy to be corrected and I'm
sure I will be if I'm wrong on that!

wrote:
I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?

Maybe your battery tester is designed only to test alkalines, which
start at 1.5v and progressively drop voltage until about exhausted at
1.2v. In comparison NiMH start at about 1.3v and slowly drop in
voltage until exhausted. So starting at 1.3v it goes to the low end of
alkaline voltage!

wrote in message
ups.com...
I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?


There are chargers that put the batteries through a "conditioning" cycle
before recharging them. This appears to be a controlled discharge step that
they say is only needed for the initial recharge and only occasionally
thereafter. I have one, a Maha c204, that gives me the longest working time
I've been able to get from NiMH AAs. They say that their later models will
revive "dead" NiMHs.

In article . com,
wrote:

I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?

Tge Ansmann Powerline 4 and Powerline 6 chargfers have a manual
discharge feature. The Ansmann Energy 8 and Energy 16 have an automatic
refreash cycle which automatically discharges cells that would benefit
from it automatically.

--
To reply no_ HPMarketing Corp.

On 15 Mar 2005 17:41:24 -0800, wrote:

I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?

Why do you want to discharge them?
NiMH batteries really don't benefit from deep discharging, so why do
it?
"Memory" effects are very slight, if you'll notice them at all, with
NiMH batteries.
It seems that you're not actually having problems, and are basing your
request on a reading from an unidentified meter; the camera has a
built-in meter, and won't use the batteries any longer if you deep
discharge them before charging them, so why bother?

--
Bill Funk
Change "g" to "a"

Digital cameras are set to turn off when the battery voltage is still 'alive
and kicking' as it were. Otherwise they may not have enough juice left in
them to be able to retract the lens and shut off properly. This can mean
that the best cells in the pack never get a full or near full discharge
though.

Some battery chargers have a conditioning function where they fully
discharge the cells before recharging. "Fully discharged" only needs to be
about 1.0v as there's hardly any charge left in a cell at this point. Even
though the memory effect isn't really a factor with NiMH there's still an
advantage in keeping groups of cells balanced, and discharging fully
occasionally is the best way to ensure this. As I don't have a conditioning
charger I've made a discharger to run 4 cells down individually to about
1.0v. It's just 4 sets of a 1 amp diode in series with a low value resistor
(about 0.5 ohm, can't remember for sure). I know when it's finished
discharging the cells because it gets quite warm during use and cools off
when it's finished. When I take the batteries out they measure 1.0v.


wrote in message
ups.com...
I have a digital camera (Canon Powershot A85) and I am interested in
how to more fully discharge the NiMH 2300 mAh AA batteries I use.
Although I have read that this type of battery is less susceptible to
"memory" problems, I have noticed that even though the camera indicates
that the batteries need to be charged, my battery tester still shows
them at the lower end of the lower end of the good/green range instead
of yellow or red. Is this normal, or is there a way to more fully
discharge them?

Thanks to everybody for the advice. The main consensus I'm taking from
this discussion is that I was needlessly worrying about trying to drain
this type of battery. I also think it would be a good idea to "move the
batteries around" (not always put the same battery in the same slot in
the camera) since it sounds like they do not all discharge at the same
rate nor to the same degree.