Energizer 15 minute NIMH Charger Report

[Evad Remlu]

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

 

[David Geesaman]

"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

 

[Paul Rubin]

"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.

 

[budgie]

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.

 

[Ron Hunter]

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

 

[Martin Riddle]

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.

 

[Don Klipstein]

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)

 

[Ron Hunter]

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

 

[Ron Hunter]

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

 

[Pooh Bear]

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

 

[Hans-Georg Michna]

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

 

[Hans-Georg Michna]

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.

 

[David Geesaman]

"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_metal_tech.asp

Dave

 

[Ron Hunter]

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

 

[Ron Hunter]

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_metal_tech.asp

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

 

[David Geesaman]

"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 )

Dave

 

[Hans-Georg Michna]

On Wed, 11 May 2005 08:00:04 -0400, "David Geesaman"
<dgeesamannospam@yahoo.com> wrote:

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

Dave,

very good site, thanks!

Hans-Georg

--
No mail, please.

 

[Hans-Georg Michna]

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

--
No mail, please.