AA battary capacity, Ah (?)

[Spehro Pefhany]

On Sun, 20 Jul 2003 17:10:25 -0500, the renowned "jakdedert"
<jdedert@bellsouth.net> wrote:

The issue of NiMH's in the cradle too long is easily surmounted...and will
get cheaper to do as the demand increases...as always with electronics and
production volume.

In my (not cheap) Siemens phone system, only a few years old, designed
for NiCds, the NiMH batteries last MUCH longer than good quality
(Panasonic) NiCds. I don't recommend it, of course, but it WORKS, and
it's a lot cheaper than either buying a new phone system or buying
dozens of NiCds.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[CMF]

Okay, back to a topic that has been covered already, and I can always look
it up, but why look up when you can ask?

I have done some testing with my HP215, and the batteries seem to still have
1.2-1.3 volts when they can no longer take a picture, but I can then put
them in my headlight flashlight (makes me look like a nerd, but works
wonders in attics) and they are just marvelous. I don't know just how long
they will go, but they still test right at the good and then '?' on my
Sperry analog multimeter. What does the Multimeter check when it does a
battery check? Voltage or amperage? The manual is hopelessly inadequate, and
about all I am real strong with is the buzz feature.

Does this pretty much indicate that 1.2 V NiMH's will not really suit me in
this camera? I can't really spend the money for a decent charger and
batteries if it really isn't going to work, because that d&%m camera is our
main battery pig. Many of the battery powered toys are magically
disappearing. I don't suppose someone in Wylie/East Plano would loan me a
set of NiMH's for a few days?

Thanks,

Maury

 

[James Waldby]

Ted Edwards wrote:

James Waldby wrote:

I agree with the advice to get a good charger with automatic
shutoff, but disagree that the Maha 204 is "absolutely right".

Either your batteries or your charger was defective. My 204 has been in
use now for almost two years with no problems whatsoever. Yours is the
first report I've seen with this problem. Did you contact the dealer
about the problem?

I agree that either the batteries or charger were defective.
Since the batteries were in use and working well until the
charger cooked them, I think the problem is in the Maha 204.
No, I didn't contact Thomas Distrib. re the problem.

-jiw

 

[Gary Coffman]

On Sat, 19 Jul 2003 22:51:19 GMT, nsnfwhite@iinet.net.au (Old Nick) wrote:

On Fri, 18 Jul 2003 14:49:00 GMT, dougmc@frenzy.com (Doug McLaren)
wrote something
NiCd have their niche, but most people want NiMH.

Given what you say, why would they? I am serious, as I am puzzled. I
thought NiMH were far better, but I am beginning to wonder why.

The big advantage is energy storage per unit weight. For portable things,
that means either longer time between recharges, or lighter equipment.

Gary

 

[Ted Edwards]

lcoe wrote:

charge NiMH, maybe a sample defecit. bu, my testing comports with a
web page that states, "NiMH" does _not_ exhibit the 'reverse' voltage
rise property of NiCAD's when reaching full charge.

They do but not as strongly. NiMH smart chargers will do NiCd but the
converse is usually false.

Ted

 

[jakdedert]

"lcoe" <lcoe@c1932201-a.attbi.com> wrote in message
news:aHFSa.96474$sY2.46201@rwcrnsc51.ops.asp.att.net...

In sci.electronics.repair Spehro Pefhany <speff@interlog.com> wrote:
On Sun, 20 Jul 2003 17:10:25 -0500, the renowned "jakdedert"
jdedert@bellsouth.net> wrote:

The issue of NiMH's in the cradle too long is easily surmounted...and
will
get cheaper to do as the demand increases...as always with electronics
and
production volume.

In my (not cheap) Siemens phone system, only a few years old, designed
for NiCds, the NiMH batteries last MUCH longer than good quality
(Panasonic) NiCds. I don't recommend it, of course, but it WORKS, and
it's a lot cheaper than either buying a new phone system or buying
dozens of NiCds.

what does, "easily surmounted" mean, wrt this discussion? --Loren

...meaning that it's fairly easy to design a circuit to stop charging once

the battery is fully charged--the advantage cited for NiCads was that they
better tolerated overcharging.

Look for a smart NiMH charger on a single chip at your electronics supplier
soon (today, maybe?)--just add transformer. Once production ramps up, and
the circuit--or ones like it--gets second-sourced, the price will go down
precipitously...like your $40 VCR which would have cost you $1500 in 1977.

jak

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the
reward"
speff@interlog.com Info for manufacturers:
http://www.trexon.com
Embedded software/hardware/analog Info for designers:
http://www.speff.com

 

[Old Nick]

On Sun, 20 Jul 2003 21:25:30 -0400, Gary Coffman <ke4zv@bellsouth.net>
wrote something
.......and in reply I say!:

That defintely seems to be the message.

So I use my crappy Unidens, which can't really handle NiCd/NiMH, run
NiMH, with one extra cell.

On Sat, 19 Jul 2003 22:51:19 GMT, nsnfwhite@iinet.net.au (Old Nick) wrote:
On Fri, 18 Jul 2003 14:49:00 GMT, dougmc@frenzy.com (Doug McLaren)
wrote something
NiCd have their niche, but most people want NiMH.

Given what you say, why would they? I am serious, as I am puzzled. I
thought NiMH were far better, but I am beginning to wonder why.

The big advantage is energy storage per unit weight. For portable things,
that means either longer time between recharges, or lighter equipment.

Gary

******************************************************************************************
Huh! Old age!. You may hate it, but let me tell you, you can't get by for long without it!

Nick White --- HEAD:Hertz Music
Please remove ns from my header address to reply via email
!!
<")
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( )
_//- \__/

 

[Old Nick]

On Sun, 20 Jul 2003 19:39:27 GMT, Ted Edwards <Ted_E@telus.net> wrote
something
.......and in reply I say!:

Thanks Ted and others. Capacity ruuuuules OK! <G>

Given what you say, why would they? I am serious, as I am puzzled. I
thought NiMH were far better, but I am beginning to wonder why.

1100mAh is about tops for AA NiCd's whereas NiMH AA's are now up to
about twice that. Twice as many pictures on your digital camera or
twice as many hours on your GPSR is a significant advantage. If you are
into caring for the environment, when they do die and go to the
landfill, NiMH does not contain any highly toxic Cadmium.

******************************************************************************************
Huh! Old age!. You may hate it, but let me tell you, you can't get by for long without it!

Nick White --- HEAD:Hertz Music
Please remove ns from my header address to reply via email
!!
<")
_/ )
( )
_//- \__/

 

[lcoe]

In rec.crafts.metalworking Ted Edwards <Ted_E@telus.net> wrote:

lcoe wrote:

charge NiMH, maybe a sample defecit. bu, my testing comports with a
web page that states, "NiMH" does _not_ exhibit the 'reverse' voltage
rise property of NiCAD's when reaching full charge.

They do but not as strongly. NiMH smart chargers will do NiCd but the
converse is usually false. > Ted

that same site states ....termination methods used for NiMH, include temp
sensing...,..timer(?),...(other?)....

the RShack unit (returned now) had the switch for NiCad<>NiMH and two
values for the "backup" timer, 2hrs for the former, 1.5 hrs for the latter.
likely the product is simply a NiCad charger with timers but they do
provide two charging currents, 200ma(?)vs 800ma. (and they lie
thru their teeth about the additional modes). --Loren

 

[Ted Edwards]

lcoe wrote:

that same site states ....termination methods used for NiMH, include temp
sensing...,..timer(?),...(other?)....

Just which site is this? Why is it anomynous? If you check the
manufacturers sites (Eveready, Ray-oVac, ...) The site I gave you
previously (on testing beatteries for cameras) and more, you will find
that your reference is simply wrong. Do a search with Google or Dogpile
and read some of the material.

the RShack unit (returned now) had the switch for NiCad<>NiMH and two
values for the "backup" timer, 2hrs for the former, 1.5 hrs for the latter.

I've never been overly impressed with Radio Shack's products so I don't
find that a very definitive source.

Ted

 

[lcoe]

In rec.crafts.metalworking Ted Edwards <Ted_E@telus.net> wrote:

lcoe wrote:

that same site states ....termination methods used for NiMH, include temp
sensing...,..timer(?),...(other?)....

Just which site is this? Why is it anomynous? If you check the

well, i just spent an hour trying to find that url, struck out, it must
have been a link from a Usnet group. similarly i cannot find another
url i visited this am that talks about "Zero Delta V" detection which
i assume is for NiMH. it doesn't reverse, just stops rising.

and that comports with yet _another_ mystery site that said a NiMH can
take 1/10C overcharge indefinitely (or it may have been 1/18C), which
shortens the life of Nicads.

manufacturers sites (Eveready, Ray-oVac, ...) The site I gave you
previously (on testing beatteries for cameras) and more, you will find
that your reference is simply wrong. Do a search with Google or Dogpile
and read some of the material.

the Thomas Distributing site has quite a bit on the charger/battery technology
and states that three methods are recognized (by MAHA) to recharge batteries,
delta V, timer, and temp, that only delta V does not overcharge. then they
say, ....good designs will incorporate all three, like the MAHA....

anyhoo, just my own personal experience, take it for what it is. --Loren

 

[Ted Edwards]

lcoe wrote:

and that comports with yet _another_ mystery site that said a NiMH can
take 1/10C overcharge indefinitely (or it may have been 1/18C), which
shortens the life of Nicads.

C/10 for continuous charging of NiMH is still controversial. Some say
C/20 and some would like to see continuous float as low as C/60. The
jury is still out on the long term stuff since the cells haven't been
around all that long and there has been considerable advance in the
technology over the last few years.

Ted

 

[CMF]

Please kind sir, can you explain what you mean by C/10 and C/20, etc? In
terms my simpleton mind can understand? Thanks.

Maury
"Ted Edwards" <Ted_E@telus.net> wrote in message
news:3F1C93C2.5194@telus.net...

lcoe wrote:

and that comports with yet _another_ mystery site that said a NiMH can
take 1/10C overcharge indefinitely (or it may have been 1/18C), which
shortens the life of Nicads.

C/10 for continuous charging of NiMH is still controversial. Some say
C/20 and some would like to see continuous float as low as C/60. The
jury is still out on the long term stuff since the cells haven't been
around all that long and there has been considerable advance in the
technology over the last few years.

Ted

 

[lcoe]

In rec.crafts.metalworking CMF <maury@hamnotspamcmf-enterprises.com> wrote:

Please kind sir, can you explain what you mean by C/10 and C/20, etc? In
terms my simpleton mind can understand? Thanks.

i don't speak for Ted, but i had that question a few days ago. from my
google results it seems to be the ratio of the battery capacity to the
recharge rate based on 1hr=max rate=batt.capacity. so 1/10C would be
a charge rate=1/10 of batt.cap/hour. a totally amateur opinion. --Loren

ps. if you don't use google, you miss a _lot_.

Maury
"Ted Edwards" <Ted_E@telus.net> wrote in message
news:3F1C93C2.5194@telus.net...
lcoe wrote:

and that comports with yet _another_ mystery site that said a NiMH can
take 1/10C overcharge indefinitely (or it may have been 1/18C), which
shortens the life of Nicads.

C/10 for continuous charging of NiMH is still controversial. Some say
C/20 and some would like to see continuous float as low as C/60. The
jury is still out on the long term stuff since the cells haven't been
around all that long and there has been considerable advance in the
technology over the last few years.

Ted

 

[Ted Edwards]

CMF wrote:

Please kind sir, can you explain what you mean by C/10 and C/20, etc? In
terms my simpleton mind can understand? Thanks.

When discussing charging and discharging currents of various
cells/batteries, the effect of these on cell performance obviously
depend on cell current - bigger cells can handle more current. In an
effort to come up with a more usefull description, we usualy reference
these to the cell capacity. So C/10 means one tenth of the cell
capacity. e.g. for a 1800milliamp-hour cell, C/10 is 180milliamps.

Hope this helps.

Ted

 

[Ted Edwards]

lcoe wrote:

ps. if you don't use google, you miss a _lot_.

Sometimes Google doesn't cut it. Then I use
http://www.Dogpile.com
This is a meta search which uses Google and a number of other search
engines.

Ted

 

[lcoe]

In dfw.forsale Ted Edwards <Ted_E@telus.net> wrote:

lcoe wrote:

ps. if you don't use google, you miss a _lot_.

Sometimes Google doesn't cut it. Then I use
http://www.Dogpile.com
This is a meta search which uses Google and a number of other search
engines. > Ted

just tried it, and yes, it looks promising. Regards, --Loren

 

[Old Nick]

On Mon, 21 Jul 2003 14:41:32 GMT, "Mac McKinzie" <mckinzi1@flash.net>
wrote something
.......and in reply I say!:
Obviously we are charging and discharging at just the right rates, and
not suffering from any memory effect ....

if only the darned batteries had the lifetime of this thread. <G

******************************************************************************************
Huh! Old age!. You may hate it, but let me tell you, you can't get by for long without it!

Nick White --- HEAD:Hertz Music
Please remove ns from my header address to reply via email
!!
<")
_/ )
( )
_//- \__/

 

[Dan Fraser]

Wal Mart sell a brand of AAs called "Digital" that are 1800mAH. I paid
under $10.00 for a set with a charger and about $6.50 for a second set.
I get 50 to 100 shots with my HP620 on a charge.

How can disposable compete with this?

I bought them at their store in the city of Orange. They actually had a
clerk there who really knew digital cameras. Who really cared about the
stuff and knew what was the best value and not just what made the
company the most money. Mind you, he was a retired Hollywood film
producer who just wanted to get out and meet people. Not your typical
worker at Wally World.

--
Dan Fraser

From Costa Mesa in sunny California
949-631-7535 Cell 714-420-7535

Check out my electronic schematics site at:
http://www.schematicsforfree.com
If you are into cars check out www.roadsters.com