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Energizer 15 minute NIMH Charger Report

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Anonymous
May 10, 2005 10:53:59 AM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

I bought the Energizer 15 minute NIMH charger for 27 USD at Wal-Mart with 4
each 2300mah batteries.

This is a very high-tech device with a 12 volt switching power supply and
zillions of smt devices inside. It will charge cells individually and its
most obvious feature is a fan located under the charging compartment. It can
be powered directly from a 12 volt car system.

To say that the batteries get HOT during a fast charge is an understatement.
They get too hot to touch! It charges AA batteries at 7 amps! I think the
fan is a bit weak for this application. I wonder if I could put a more
powerful fan in it?

After a few weeks of using this thing I have considered the unit 'pretty
good' but not perfect. It sometimes recognizes fully charged or partially
charged batteries as bad and won't charge them. Older batteries seem to need
'conditioning' before they will accept a fast charge. The individual cell
charging opens up the possibility that all cells don't get charged equally.
After fast charging in this unit, I can put the cooled cells into my old
Maha charger and it takes about an hour to go 'green' and say they are
really full. This leads me to believe that it doesn't always completely
charge the batteries.

One old off-brand battery spurted fluid when fast charging in this unit.

I wonder how many fast-charge cycles the new 2500mah will take using this
unit. I will let you know.

Evad
Anonymous
May 10, 2005 1:16:52 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

> I wonder if I could put a more powerful fan in it?

This may screw-up the fast-charge algorithm, which was undoubtedly
designed with only the existing fan. (It is impressive that it has a
built-in fan!)

> They get too hot to touch!

Thus the reason for the fan, to cool your fingers :-).

If you do manage to dissect/figure out the charge algorithm, it'd be
interesting. The "consumer" battery companies have always been
half-assed about telling us techies things like battery charge rates,
capacities, etc. Obviously they don't want to turn market
differentiation into a simple single number, when they can have a
rabbit banging a drum instead!

Tim.
Anonymous
May 10, 2005 2:39:44 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

"Evad Remlu" <evad@dodgeit.com> writes:
> To say that the batteries get HOT during a fast charge is an
> understatement. They get too hot to touch! It charges AA batteries
> at 7 amps! I think the fan is a bit weak for this application. I
> wonder if I could put a more powerful fan in it?

Mine didn't get anywhere near that hot. They got warm, but not
uncomfortably so. You didn't put on cells that were already charged,
did you? That can confuse the charger and the the cells hot. I've
seen it described before.
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Anonymous
May 10, 2005 5:13:50 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

"Tim Shoppa" <shoppa@trailing-edge.com> wrote in message
news:1115741812.123180.84360@o13g2000cwo.googlegroups.com...
> If you do manage to dissect/figure out the charge algorithm, it'd be
> interesting. The "consumer" battery companies have always been
> half-assed about telling us techies things like battery charge rates,
> capacities, etc. Obviously they don't want to turn market
> differentiation into a simple single number, when they can have a
> rabbit banging a drum instead!
>
> Tim.

Does this site contain the info you're after?
http://data.energizer.com/

Dave
Anonymous
May 11, 2005 12:28:46 AM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

David Geesaman wrote:
> "Tim Shoppa" <shoppa@trailing-edge.com> wrote in message
> news:1115741812.123180.84360@o13g2000cwo.googlegroups.com...
>
>>If you do manage to dissect/figure out the charge algorithm, it'd be
>>interesting. The "consumer" battery companies have always been
>>half-assed about telling us techies things like battery charge rates,
>>capacities, etc. Obviously they don't want to turn market
>>differentiation into a simple single number, when they can have a
>>rabbit banging a drum instead!
>>
>>Tim.
>
>
> Does this site contain the info you're after?
> http://data.energizer.com/
>
> Dave
>
>
It seems that advertisers don't want to provide ANY kind of usable
information about their products. Most advertising is all about sizzle,
and not a word about the steak.


--
Ron Hunter rphunter@charter.net
Anonymous
May 11, 2005 4:56:41 AM

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

"Evad Remlu" <evad@dodgeit.com> wrote in message news:4280bddb_2@x-privat.org...
>
> I bought the Energizer 15 minute NIMH charger for 27 USD at Wal-Mart with 4
> each 2300mah batteries.
>
> This is a very high-tech device with a 12 volt switching power supply and
> zillions of smt devices inside. It will charge cells individually and its
> most obvious feature is a fan located under the charging compartment. It can
> be powered directly from a 12 volt car system.
>
> To say that the batteries get HOT during a fast charge is an understatement.
> They get too hot to touch! It charges AA batteries at 7 amps! I think the
> fan is a bit weak for this application. I wonder if I could put a more
> powerful fan in it?
>
> After a few weeks of using this thing I have considered the unit 'pretty
> good' but not perfect. It sometimes recognizes fully charged or partially
> charged batteries as bad and won't charge them. Older batteries seem to need
> 'conditioning' before they will accept a fast charge. The individual cell
> charging opens up the possibility that all cells don't get charged equally.
> After fast charging in this unit, I can put the cooled cells into my old
> Maha charger and it takes about an hour to go 'green' and say they are
> really full. This leads me to believe that it doesn't always completely
> charge the batteries.
>
> One old off-brand battery spurted fluid when fast charging in this unit.
>
> I wonder how many fast-charge cycles the new 2500mah will take using this
> unit. I will let you know.
>
> Evad



Evad.

Why do you need to charge the NI-MH batteries so quickly? My info is that they will be ruined when
they get even moderately hot, and no matter what fan you use it will not be able to cool the inside where the
damage will be done.

Why not buy more batteries and charge them all together at the prescribed safe rate i.e. one tenth of the
current, 250ma for the 2500 ma AA size.

You can get cheap AA holders, join them together and charge a dozen r two at the same time. There are lots of
different voltage power packs to be found. You would need to buy a milliamp meter but there are very good ones
to be had for approx $5. Multimeters that is, volts amps and ohms.

Just a thought.

John.
Anonymous
May 11, 2005 4:56:42 AM

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

"John Bates" <miracle@bates33100.freeserve.co.uk> writes:
> Why do you need to charge the NI-MH batteries so quickly?

There are times when you need to use them right away. There are other
times when you don't have power for the charger available for hours at
a time. Most times, a little advance planning and slower charging is
better.

> My info is that they will be ruined when they get even moderately
> hot, and no matter what fan you use it will not be able to cool the
> inside where the damage will be done.

The cells are almost like capacitors until they're around 80% charged.
They don't get hot from the fast charging. Once they reach that 80%
level, the charger notices the transition and switches to trickle
charge. There is a gap (deficiency, I guess) in that if you put the
cells on the charger when they're already almost full, the charger
still tries to fast charge them and they do get awfully hot.
Anonymous
May 11, 2005 4:56:43 AM

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

On 10 May 2005 17:14:11 -0700, Paul Rubin
<http://phr.cx@NOSPAM.invalid&gt; wrote:

> The cells are almost like capacitors until they're around 80% charged.
> They don't get hot from the fast charging. Once they reach that 80%
> level, the charger notices the transition and switches to trickle
> charge. There is a gap (deficiency, I guess) in that if you put the
> cells on the charger when they're already almost full, the charger
> still tries to fast charge them and they do get awfully hot.

That would seem to be a design that needs to be improved. I have
several audio devices that have built-in NiMH chargers. One in
particular, a Sony CD player will not do that. If you try having it
charge a fully charged battery, its display will indicate that the
battery is fully charged within a couple of seconds. Not all of
Sony's chargers are this smart.
Anonymous
May 11, 2005 12:00:04 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

"Ron Hunter" <rphunter@charter.net> wrote in message
news:jddge.2576$rt1.1666@fe04.lga...
> David Geesaman wrote:
>> "Tim Shoppa" <shoppa@trailing-edge.com> wrote in message
>> news:1115741812.123180.84360@o13g2000cwo.googlegroups.com...
>>
>>>If you do manage to dissect/figure out the charge algorithm, it'd be
>>>interesting. The "consumer" battery companies have always been
>>>half-assed about telling us techies things like battery charge rates,
>>>capacities, etc. Obviously they don't want to turn market
>>>differentiation into a simple single number, when they can have a
>>>rabbit banging a drum instead!
>>>
>>>Tim.
>>
>>
>> Does this site contain the info you're after?
>> http://data.energizer.com/
>>
>> Dave
> It seems that advertisers don't want to provide ANY kind of usable
> information about their products. Most advertising is all about sizzle,
> and not a word about the steak.
> --
> Ron Hunter rphunter@charter.net

Did you read the site Ron? It's got all the technical specifications I've
ever needed. Granted, this info isn't in their advertisements or on the
consumer area of their website, but it is readily available.

Duracell NiMH:
http://www.duracell.com/oem/rechargeable/Nickel/nickel_...

Dave
May 11, 2005 1:12:22 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

On Tue, 10 May 2005 06:53:59 -0700, "Evad Remlu" <evad@dodgeit.com> wrote:

>
>I bought the Energizer 15 minute NIMH charger for 27 USD at Wal-Mart with 4
>each 2300mah batteries.
>
>This is a very high-tech device with a 12 volt switching power supply and
>zillions of smt devices inside. It will charge cells individually and its
>most obvious feature is a fan located under the charging compartment. It can
>be powered directly from a 12 volt car system.
>
>To say that the batteries get HOT during a fast charge is an understatement.
>They get too hot to touch! It charges AA batteries at 7 amps! I think the
>fan is a bit weak for this application. I wonder if I could put a more
>powerful fan in it?

I'd be leery of any NiMH charger that got cells that hot. 45C is considered by
most to be the upper terminating temp, at which temp you can certainlytouch
them.

>After a few weeks of using this thing I have considered the unit 'pretty
>good' but not perfect. It sometimes recognizes fully charged or partially
>charged batteries as bad and won't charge them. Older batteries seem to need
>'conditioning' before they will accept a fast charge. The individual cell
>charging opens up the possibility that all cells don't get charged equally.
>After fast charging in this unit, I can put the cooled cells into my old
>Maha charger and it takes about an hour to go 'green' and say they are
>really full. This leads me to believe that it doesn't always completely
>charge the batteries.
>
>One old off-brand battery spurted fluid when fast charging in this unit.

A fast charge unit that pumps that sort of current into cells should only be
used with cells designed for high rates.

>I wonder how many fast-charge cycles the new 2500mah will take using this
>unit. I will let you know.

I suspect that the design trades cell cyle life for the "convenience" of
superfast charging.
Anonymous
May 11, 2005 1:12:23 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

I concur 45c is on most Nimh data sheets. And can feel hot to some people.

Also fast charging , only charges the cell to 90-95% of capacity. So it sounds like the charger is working as designed.

Cheers

"budgie" <me@privacy.net> wrote in message news:7km2815sjcrhqgu4j7en727m3q8hoq7se3@4ax.com...
> On Tue, 10 May 2005 06:53:59 -0700, "Evad Remlu" <evad@dodgeit.com> wrote:
>
> >
> >I bought the Energizer 15 minute NIMH charger for 27 USD at Wal-Mart with 4
> >each 2300mah batteries.
> >
> >This is a very high-tech device with a 12 volt switching power supply and
> >zillions of smt devices inside. It will charge cells individually and its
> >most obvious feature is a fan located under the charging compartment. It can
> >be powered directly from a 12 volt car system.
> >
> >To say that the batteries get HOT during a fast charge is an understatement.
> >They get too hot to touch! It charges AA batteries at 7 amps! I think the
> >fan is a bit weak for this application. I wonder if I could put a more
> >powerful fan in it?
>
> I'd be leery of any NiMH charger that got cells that hot. 45C is considered by
> most to be the upper terminating temp, at which temp you can certainlytouch
> them.
>
> >After a few weeks of using this thing I have considered the unit 'pretty
> >good' but not perfect. It sometimes recognizes fully charged or partially
> >charged batteries as bad and won't charge them. Older batteries seem to need
> >'conditioning' before they will accept a fast charge. The individual cell
> >charging opens up the possibility that all cells don't get charged equally.
> >After fast charging in this unit, I can put the cooled cells into my old
> >Maha charger and it takes about an hour to go 'green' and say they are
> >really full. This leads me to believe that it doesn't always completely
> >charge the batteries.
> >
> >One old off-brand battery spurted fluid when fast charging in this unit.
>
> A fast charge unit that pumps that sort of current into cells should only be
> used with cells designed for high rates.
>
> >I wonder how many fast-charge cycles the new 2500mah will take using this
> >unit. I will let you know.
>
> I suspect that the design trades cell cyle life for the "convenience" of
> superfast charging.
Anonymous
May 11, 2005 1:12:23 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

budgie wrote:
> On Tue, 10 May 2005 06:53:59 -0700, "Evad Remlu" <evad@dodgeit.com> wrote:
>
>
>>I bought the Energizer 15 minute NIMH charger for 27 USD at Wal-Mart with 4
>>each 2300mah batteries.
>>
>>This is a very high-tech device with a 12 volt switching power supply and
>>zillions of smt devices inside. It will charge cells individually and its
>>most obvious feature is a fan located under the charging compartment. It can
>>be powered directly from a 12 volt car system.
>>
>>To say that the batteries get HOT during a fast charge is an understatement.
>>They get too hot to touch! It charges AA batteries at 7 amps! I think the
>>fan is a bit weak for this application. I wonder if I could put a more
>>powerful fan in it?
>
>
> I'd be leery of any NiMH charger that got cells that hot. 45C is considered by
> most to be the upper terminating temp, at which temp you can certainlytouch
> them.
>
>
>>After a few weeks of using this thing I have considered the unit 'pretty
>>good' but not perfect. It sometimes recognizes fully charged or partially
>>charged batteries as bad and won't charge them. Older batteries seem to need
>>'conditioning' before they will accept a fast charge. The individual cell
>>charging opens up the possibility that all cells don't get charged equally.
>>After fast charging in this unit, I can put the cooled cells into my old
>>Maha charger and it takes about an hour to go 'green' and say they are
>>really full. This leads me to believe that it doesn't always completely
>>charge the batteries.
>>
>>One old off-brand battery spurted fluid when fast charging in this unit.
>
>
> A fast charge unit that pumps that sort of current into cells should only be
> used with cells designed for high rates.
>
>
>>I wonder how many fast-charge cycles the new 2500mah will take using this
>>unit. I will let you know.
>
>
> I suspect that the design trades cell cyle life for the "convenience" of
> superfast charging.

I am pretty sure the fast charge will shorten the total use life by some
degree. Just how much seems to lack exploration. However, given the
low cost of NIMH batteries, the convenience will probably outweigh the
shorter use life. If a set of NIMH batteries (4) costs $12, and slow
charged can be recharged 500 times, and will take 150 pictures/charge,
the cost per picture is $0.0016 per picture. If fast charging reduces
this to only 200 charges, then the cost rises to $.004 per picture. It
seems worth the money to me to have the extra speed. Those for whom the
extra .24 cents/picture is excessive, can stick with the slower charger.


--
Ron Hunter rphunter@charter.net
Anonymous
May 11, 2005 1:12:24 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

In article <aDege.684$q44.206@trndny05>, Martin Riddle wrote in part:

>I concur 45c is on most Nimh data sheets. And can feel hot to some people.

I suspect somehow that somewhat hotter is not too bad if done for only
15 minutes per charge cycle.

I have the Ray-O-Vac 15 minute charger and "IC3" cells that came with it
and more of these same "IC3" cells. They get definitely hotter than 45 C.
I just topped off a few cells just so that I coyuld read them with my
recently-acquired "Raytek" remote thermometer, and got 58 C as a high
reading in an ambient of 27 C. I expect that full charge from "empty"
will heat up the cells a little more than this.

- Don Klipstein (don@misty.com)
Anonymous
May 11, 2005 1:12:24 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

Martin Riddle wrote:

> I concur 45c is on most Nimh data sheets. And can feel hot to some people.

Assessment of *hot* is very subjective indeed.

> Also fast charging , only charges the cell to 90-95% of capacity. So it sounds like the charger is working as designed.

Yup.


Graham
Anonymous
May 11, 2005 1:12:25 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

Don Klipstein wrote:
> In article <aDege.684$q44.206@trndny05>, Martin Riddle wrote in part:
>
>
>>I concur 45c is on most Nimh data sheets. And can feel hot to some people.
>
>
> I suspect somehow that somewhat hotter is not too bad if done for only
> 15 minutes per charge cycle.
>
> I have the Ray-O-Vac 15 minute charger and "IC3" cells that came with it
> and more of these same "IC3" cells. They get definitely hotter than 45 C.
> I just topped off a few cells just so that I coyuld read them with my
> recently-acquired "Raytek" remote thermometer, and got 58 C as a high
> reading in an ambient of 27 C. I expect that full charge from "empty"
> will heat up the cells a little more than this.
>
> - Don Klipstein (don@misty.com)

As I understand the mechanism, recharging from empty will probably not
result in a higher maximum temp. Recharging from almost full will
result in higher temps, however.


--
Ron Hunter rphunter@charter.net
Anonymous
May 11, 2005 1:26:08 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

David Geesaman wrote:
> "Ron Hunter" <rphunter@charter.net> wrote in message
> news:jddge.2576$rt1.1666@fe04.lga...
>
>>David Geesaman wrote:
>>
>>>"Tim Shoppa" <shoppa@trailing-edge.com> wrote in message
>>>news:1115741812.123180.84360@o13g2000cwo.googlegroups.com...
>>>
>>>
>>>>If you do manage to dissect/figure out the charge algorithm, it'd be
>>>>interesting. The "consumer" battery companies have always been
>>>>half-assed about telling us techies things like battery charge rates,
>>>>capacities, etc. Obviously they don't want to turn market
>>>>differentiation into a simple single number, when they can have a
>>>>rabbit banging a drum instead!
>>>>
>>>>Tim.
>>>
>>>
>>> Does this site contain the info you're after?
>>> http://data.energizer.com/
>>>
>>> Dave
>>
>>It seems that advertisers don't want to provide ANY kind of usable
>>information about their products. Most advertising is all about sizzle,
>>and not a word about the steak.
>>--
>>Ron Hunter rphunter@charter.net
>
>
> Did you read the site Ron? It's got all the technical specifications I've
> ever needed. Granted, this info isn't in their advertisements or on the
> consumer area of their website, but it is readily available.
>
> Duracell NiMH:
> http://www.duracell.com/oem/rechargeable/Nickel/nickel_...
>
> Dave
>
>
The issue wasn't website information, but advertising, which often
includes NOTHING of substance about the product (some ads don't even
SHOW, or mention, their product!), just the company name.


--
Ron Hunter rphunter@charter.net
Anonymous
May 11, 2005 3:02:46 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

"Ron Hunter" <rphunter@charter.net> wrote in message
news:5Coge.3481$sV7.1458@fe02.lga...
> The issue wasn't website information, but advertising, which often
> includes NOTHING of substance about the product (some ads don't even SHOW,
> or mention, their product!), just the company name.

I gave up on the quality of advertising somewhere as a child, when I
realized toys weren't as big as the ads made them appear.

I focus my complaining on more influenceable things like traffic :o )

Dave
Anonymous
May 11, 2005 3:16:34 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

On 10 May 2005 10:39:44 -0700, Paul Rubin
<http://phr.cx@NOSPAM.invalid&gt; wrote:

>"Evad Remlu" <evad@dodgeit.com> writes:

>> To say that the batteries get HOT during a fast charge is an
>> understatement. They get too hot to touch! It charges AA batteries
>> at 7 amps! I think the fan is a bit weak for this application. I
>> wonder if I could put a more powerful fan in it?

>Mine didn't get anywhere near that hot. They got warm, but not
>uncomfortably so. You didn't put on cells that were already charged,
>did you? That can confuse the charger and the the cells hot. I've
>seen it described before.

Paul,

the charger should recognize that and stop charging in time.

If not, it would have to carry a warning not to insert fully
charged batteries.

Hans-Georg

--
No mail, please.
Anonymous
May 11, 2005 3:16:34 PM

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

On Wed, 11 May 2005 00:56:41 +0100, "John Bates"
<miracle@bates33100.freeserve.co.uk> wrote:

>Why do you need to charge the NI-MH batteries so quickly? My info is that they will be ruined when
>they get even moderately hot

John,

that doesn't coincide with the information I have. The cells can
withstand some quite high temperature, certainly too hot to
touch.

Hans-Georg

--
No mail, please.
Anonymous
May 11, 2005 3:16:35 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

On Wed, 11 May 2005 01:07:24 -0500, Ron Hunter
<rphunter@charter.net> wrote:

>I am pretty sure the fast charge will shorten the total use life by some
>degree. Just how much seems to lack exploration. However, given the
>low cost of NIMH batteries, the convenience will probably outweigh the
>shorter use life. If a set of NIMH batteries (4) costs $12, and slow
>charged can be recharged 500 times, and will take 150 pictures/charge,
>the cost per picture is $0.0016 per picture. If fast charging reduces
>this to only 200 charges, then the cost rises to $.004 per picture. It
>seems worth the money to me to have the extra speed. Those for whom the
>extra .24 cents/picture is excessive, can stick with the slower charger.

Ron,

add to this that you may need fewer batteries, because you may
only need one set for one device, rather than two (or two,
rather than three).

In your theory, you would then have to discard them more often
and replace them with new ones, but your 500/200 figures are
purely speculative. We don't even know whether ultra-quick
charging reduces the endurance of the cells at all.

Hans-Georg

--
No mail, please.
Anonymous
May 11, 2005 3:16:35 PM

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

Hans-Georg Michna wrote:
> On Wed, 11 May 2005 00:56:41 +0100, "John Bates"
> <miracle@bates33100.freeserve.co.uk> wrote:
>
>
>>Why do you need to charge the NI-MH batteries so quickly? My info is that they will be ruined when
>>they get even moderately hot
>
>
> John,
>
> that doesn't coincide with the information I have. The cells can
> withstand some quite high temperature, certainly too hot to
> touch.
>
> Hans-Georg
>
I suppose it depends on how one defines 'moderately hot'. Certainly if
it causes significant outgassing, the cell is probably harmed, permanently.


--
Ron Hunter rphunter@charter.net
Anonymous
May 11, 2005 3:16:36 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

Hans-Georg Michna wrote:
> On Wed, 11 May 2005 01:07:24 -0500, Ron Hunter
> <rphunter@charter.net> wrote:
>
>
>>I am pretty sure the fast charge will shorten the total use life by some
>>degree. Just how much seems to lack exploration. However, given the
>>low cost of NIMH batteries, the convenience will probably outweigh the
>>shorter use life. If a set of NIMH batteries (4) costs $12, and slow
>>charged can be recharged 500 times, and will take 150 pictures/charge,
>>the cost per picture is $0.0016 per picture. If fast charging reduces
>>this to only 200 charges, then the cost rises to $.004 per picture. It
>>seems worth the money to me to have the extra speed. Those for whom the
>>extra .24 cents/picture is excessive, can stick with the slower charger.
>
>
> Ron,
>
> add to this that you may need fewer batteries, because you may
> only need one set for one device, rather than two (or two,
> rather than three).
>
> In your theory, you would then have to discard them more often
> and replace them with new ones, but your 500/200 figures are
> purely speculative. We don't even know whether ultra-quick
> charging reduces the endurance of the cells at all.
>
> Hans-Georg
>
I was trying to illustrate that it probably doesn't matter unless one is
REALLY strapped for cash, in which case buying a digital camera probably
wasn't a good idea.
In the one case, 10,000 pictures would cost 16 cents, in the other, 40
cents. Not many people would consider this significant.


--
Ron Hunter rphunter@charter.net
Anonymous
May 11, 2005 9:38:07 PM

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

On Wed, 11 May 2005 09:21:01 -0500, Ron Hunter
<rphunter@charter.net> wrote:

>I suppose it depends on how one defines 'moderately hot'. Certainly if
>it causes significant outgassing, the cell is probably harmed, permanently.

Ron,

I just read the Duracell site. Yes, it seems that higher
temperatures are detrimental.

But, what they showed, apparently referred to a high temperature
through the entire time of charging, not just to a few hot
minutes at the end.

Hans-Georg

--
No mail, please.
Anonymous
May 11, 2005 9:38:08 PM

Archived from groups: sci.electronics.design,rec.photo.digital (More info?)

On Wed, 11 May 2005 09:24:27 -0500, Ron Hunter
<rphunter@charter.net> wrote:

>Hans-Georg Michna wrote:

>> add to this that you may need fewer batteries, because you may
>> only need one set for one device, rather than two (or two,
>> rather than three).
>>
>> In your theory, you would then have to discard them more often
>> and replace them with new ones, but your 500/200 figures are
>> purely speculative. We don't even know whether ultra-quick
>> charging reduces the endurance of the cells at all.

>I was trying to illustrate that it probably doesn't matter unless one is
>REALLY strapped for cash, in which case buying a digital camera probably
>wasn't a good idea.
>In the one case, 10,000 pictures would cost 16 cents, in the other, 40
>cents. Not many people would consider this significant.

Ron,

yes, I understand. It's one of those flat optimum decisions
where it doesn't matter much how you decide.

Hans-Georg

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No mail, please.
Anonymous
May 11, 2005 9:38:08 PM

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

While the Energizer charger may not be so safe (per your leaking
battery), the Rayovac 15 minute charger, IMO, is one of the best designs
I've encountered in years, and works fine.

Yes, the cells do get hot due to the fast charging, but the cells are
=safely= charged.

Why?

The IC3 charging technology differs from the traditional time/temp/etc.
charge monitoring methods of the past.

"How does the new 15-Minute Rechargeable system work?

The I-C3 technology™ (In-Cell Charge Control) used in the 15-Minute
Rechargeable System allows unsurpassed charging speed due to the
system's ability to control the internal cell pressure. With currently
available technology, expensive smart electronics must be built into the
fast chargers to monitor voltage and temperature and avoid excessive
pressure build-up. With I-C3 technology, the batteries will control
internal pressure. This breakthrough will now allow faster charging."

http://www.rayovac.com/recharge/faq.htm#ic31

http://a330.g.akamai.net/7/330/2540/20020708202139/www....

http://www.edn.com/article/CA231590.html

---

You do have to buy I-C3 NiMh Cells to access the 15 minute charge cycle
(other cells only charge overnight), but it's a far 'safer' alternative
to watching your regular NiMh cells melt in the poorer Energizer charger.

Anyways, the 2AA/AAA all-in-one Rayovac charger from Walmart works great
here! Never had a problem with it, you simply plug it in and go! And
the cells last a very long time in my devices. Recommended!
Anonymous
May 11, 2005 9:38:09 PM

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

David Chien wrote:
> While the Energizer charger may not be so safe (per your leaking
> battery), the Rayovac 15 minute charger, IMO, is one of the best designs
> I've encountered in years, and works fine.
>
> Yes, the cells do get hot due to the fast charging, but the cells are
> =safely= charged.
>
> Why?
>
> The IC3 charging technology differs from the traditional time/temp/etc.
> charge monitoring methods of the past.
>
> "How does the new 15-Minute Rechargeable system work?
>
> The I-C3 technology™ (In-Cell Charge Control) used in the 15-Minute
> Rechargeable System allows unsurpassed charging speed due to the
> system's ability to control the internal cell pressure. With currently
> available technology, expensive smart electronics must be built into the
> fast chargers to monitor voltage and temperature and avoid excessive
> pressure build-up. With I-C3 technology, the batteries will control
> internal pressure. This breakthrough will now allow faster charging."
>
> http://www.rayovac.com/recharge/faq.htm#ic31
>
> http://a330.g.akamai.net/7/330/2540/20020708202139/www....
>
>
> http://www.edn.com/article/CA231590.html
>
> ---
>
> You do have to buy I-C3 NiMh Cells to access the 15 minute charge cycle
> (other cells only charge overnight), but it's a far 'safer' alternative
> to watching your regular NiMh cells melt in the poorer Energizer charger.
>
> Anyways, the 2AA/AAA all-in-one Rayovac charger from Walmart works great
> here! Never had a problem with it, you simply plug it in and go! And
> the cells last a very long time in my devices. Recommended!

While, as I mentioned in another post, it probably doesn't matter in the
'real world', any time a battery vents, it has been damaged. The design
is to allow the battery to charge that fast without exploding. It isn't
necessarily a good thing to vent, but it IS better than exploding!


--
Ron Hunter rphunter@charter.net
Anonymous
May 11, 2005 11:46:18 PM

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

On Wed, 11 May 2005 16:55:21 -0500, Ron Hunter wrote:

> While, as I mentioned in another post, it probably doesn't matter in
> the 'real world', any time a battery vents, it has been damaged.

Well, it'll lose a bit of its capacity, but I haven't come across
data showing the typical amount of venting (when it occurs) and how
much of it has to occur before the cell needs to be replaced. You
could also say that cells are 'damaged' by normal use, since that
reduces capacity too.


> The design is to allow the battery to charge that fast without exploding.
> It isn't necessarily a good thing to vent, but it IS better than exploding!

Hence the newsgroups and why you probably benefit by gravitating
to some of the more heated threads. :) 
Anonymous
May 12, 2005 1:15:19 AM

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

ASAAR wrote:
> On Wed, 11 May 2005 16:55:21 -0500, Ron Hunter wrote:
>
>
>>While, as I mentioned in another post, it probably doesn't matter in
>>the 'real world', any time a battery vents, it has been damaged.
>
>
> Well, it'll lose a bit of its capacity, but I haven't come across
> data showing the typical amount of venting (when it occurs) and how
> much of it has to occur before the cell needs to be replaced. You
> could also say that cells are 'damaged' by normal use, since that
> reduces capacity too.
>
>
>
>> The design is to allow the battery to charge that fast without exploding.
>> It isn't necessarily a good thing to vent, but it IS better than exploding!
>
>
> Hence the newsgroups and why you probably benefit by gravitating
> to some of the more heated threads. :) 
>

I almost overlooked the humor there. Grin.

Yes, one could say that recharging causes damage in most cases,
otherwise the cells would last forever.


--
Ron Hunter rphunter@charter.net
!