Discharging rechargable batteries

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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?
 
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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!
 

Ron

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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!

tngtest@attglobal.net 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?
>
 
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<tngtest@attglobal.net> wrote in message
news:1110937284.759711.97040@z14g2000cwz.googlegroups.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
 

Gene

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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



<tngtest@attglobal.net> wrote in message
news:1110937284.759711.97040@z14g2000cwz.googlegroups.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?
>
 
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In article <1110937284.759711.97040@z14g2000cwz.googlegroups.com>,
tngtest@attglobal.net 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.
 

martin

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<tngtest@attglobal.net> wrote in message
news:1110937284.759711.97040@z14g2000cwz.googlegroups.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.
 
G

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On 15 Mar 2005 17:41:24 -0800, tngtest@attglobal.net 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"
 
G

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Archived from groups: rec.photo.digital (More info?)

"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."

I used to race radio controlled cars using NiCad batteries. I have a
set of resistors on clip terminals to fully discharge each cell. I use
a voltmeter and a notebook to see how the batteries are responding
to conditioning and to choose which batteries to run each week.
NiCads are know to respond well to a deep discharge, NMH are not.

"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."

Try using a real voltmeter and a small load (1K Ohms) and report back
the
voltage.

"Is this normal, or is there a way to more fully discharge them?"

As the others have said, I don't know why you want to fully discharge
them,
but if you really want to discharge tham, attach a 100 Ohm resistor
between
each cell and wait a week. Once again, I don't know why you would want
to
do so.
 
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"Gene" <genes@thegateway.net> wrote:

> 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
>
Definitely so. You want to avoid completely discharging NiMH batteries. I'm
curious if the OP's battery tester was designed for carbon/zinc or akaline
batteries (1.5v) instead of NiMH or NiCad (1.2v). This would explain the
low readings.

The mAh rating has NOTHING to do with the full-charge voltage.
 
G

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Big Bill <bill@pipping.com> wrote:


> Why do you want to discharge them?
> NiMH batteries really don't benefit from deep discharging, so why do
> it?
>

Not only do they not benefit but it drastically reduces their life.
 
G

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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.
 
G

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Tom Gordon wrote:
> 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.


Hi Tom...

It's completely irrelevant how you put them in the camera...
they're in series.

However, keep them in sets... soon as you buy or open
a new package mark them somehow to make them unique.

Then use them and charge them together.

Ken
 

Marvin

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tngtest@attglobal.net 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?
>
The camera is not a battery tester. Most likely, it is indicatiing the capacity of the batteries to
deliver the current it needs.