Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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  #1   Report Post  
lcoe
 
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Default AA battary capacity, Ah (?)


there was thread here about battery life, and some of the new technology
wrt digital cameras (eating AA Alkalines). i got suckered into buying
another camera, and guess what, it really EATS AA'a, changing batteries
would be a full time job.

the previous owner said he used 1600mah NMiH rechargeables and got
50-60 shots, some w/flash, some without the lcd on, but was generally
happy.

Question: before i even think about buying into an expensive set up
for only occaisional use, i need to know what is the actual capacity of
the current crop of AA Alkaline battery. googling now, but find nothing
beyond suggested uses on manufacturers sites.

Thanks! --Loren

  #2   Report Post  
Remove SPAM From Address to Reply
 
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Loren,

AA alkalines are higher capacity than the rechargeables,
but they are best utilized at slower rates of discharge.
Cameras are high rate-of-discharge applications and that's
why alkaline AAs don't deliver the performance you'd
normally expect.

Your friend was correct in recommending NiMH rechargeables,
you can get a decent set of 4 and a charger for about
$10 if you look for sales. Never need to pay more than
about $15.

We can discuss it further when we get together regarding
the guns, I've used NiMH and high-capacity NiCads in
many applications over the years.

Martin


lcoe wrote in message news:%rVOa.17979$ye4.16543@sccrnsc01...
there was thread here about battery life, and some of the new technology
wrt digital cameras (eating AA Alkalines). i got suckered into buying
another camera, and guess what, it really EATS AA'a, changing batteries
would be a full time job.

the previous owner said he used 1600mah NMiH rechargeables and got
50-60 shots, some w/flash, some without the lcd on, but was generally
happy.

Question: before i even think about buying into an expensive set up
for only occaisional use, i need to know what is the actual capacity of
the current crop of AA Alkaline battery. googling now, but find nothing
beyond suggested uses on manufacturers sites.

Thanks! --Loren

  #3   Report Post  
Ted Edwards
 
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Zack Lau wrote:

You ought to be able to find the info on a Duracell web
site. A couple of years ago, they said 2215 mAh at a cutoff
voltage of 0.8 volts. Problem is, most modern cameras won't
run with a battery that low,


Asside from that, you must specify the drain rate. Compare the Ah
capacity at 20 hour rate and 1 hour rate. Quite a difference. It
depends on both cell chemistry and structure.

I have a 12V (10 cell), 60Ah set of vented cell, sintered plate NiCd's
that *tested* 500a for 5 minutes to a 9V end point after cold soaking
overnight at -40. Try that with a 60Ah lead-acid battery!

Ted


  #4   Report Post  
Ted Edwards
 
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Your friend was correct in recommending NiMH rechargeables,
you can get a decent set of 4 and a charger for about
$10 if you look for sales. Never need to pay more than
about $15.


Please don't do that! Those cheap chargers are either constant current
or timer terminated. Pay somewhat more and you can charge your
batteries whenever you feel like it without worrying about state of
charge. Ray-o-vac has a good charger but, personally, I like the Maha
line. My 204 isn't as versatile as some of the newer ones but it works
well. I paid Cdn$30 for it a couple years ago.
For example, see
http://www.thomas-distributing.com/batteries.htm

Ted


  #5   Report Post  
Len Turnbow
 
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(...)
there was thread here about battery life, and some of the new technology
wrt digital cameras (eating AA Alkalines). i got suckered into buying
another camera, and guess what, it really EATS AA'a, changing batteries
would be a full time job.

the previous owner said he used 1600mah NMiH rechargeables and got
50-60 shots, some w/flash, some without the lcd on, but was generally
happy.

Question: before i even think about buying into an expensive set up
for only occaisional use, i need to know what is the actual capacity of
the current crop of AA Alkaline battery. googling now, but find nothing
beyond suggested uses on manufacturers sites.

Thanks! --Loren


Maybe you could check out rechargables?
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM

--Len




  #6   Report Post  
Eric R Snow
 
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On Wed, 09 Jul 2003 21:04:18 GMT, Ted Edwards wrote:

Your friend was correct in recommending NiMH rechargeables,
you can get a decent set of 4 and a charger for about
$10 if you look for sales. Never need to pay more than
about $15.


Please don't do that! Those cheap chargers are either constant current
or timer terminated. Pay somewhat more and you can charge your
batteries whenever you feel like it without worrying about state of
charge. Ray-o-vac has a good charger but, personally, I like the Maha
line. My 204 isn't as versatile as some of the newer ones but it works
well. I paid Cdn$30 for it a couple years ago.
For example, see
http://www.thomas-distributing.com/batteries.htm

Ted

Greetings Ted and Icoe,
What Ted Says! When I bought my digital camera I researched it (with
lots of help from RCM) and the gist of the battery life question was
to get the 1800 mah nimh batteries, made by MAHA, from Thomas
Distributing. They lasted longer that alkaline batteries in digital
cameras. And they can be thrown in the charger any time. When the
batteries get about halfway down I exchange 'em. Keeps plenty o charge
in the camera. And battery life is great. much better than the manual
said to expect with alkalines. Thomas Distributing has a battery and
charger deal. I just got four batteries as my camera uses two. Works
great.
Cheers,
Eric R Snow
  #7   Report Post  
clare @ snyder.on .ca
 
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On Wed, 09 Jul 2003 21:04:18 GMT, Ted Edwards wrote:

Your friend was correct in recommending NiMH rechargeables,
you can get a decent set of 4 and a charger for about
$10 if you look for sales. Never need to pay more than
about $15.


Please don't do that! Those cheap chargers are either constant current
or timer terminated. Pay somewhat more and you can charge your
batteries whenever you feel like it without worrying about state of
charge. Ray-o-vac has a good charger but, personally, I like the Maha
line. My 204 isn't as versatile as some of the newer ones but it works
well. I paid Cdn$30 for it a couple years ago.
For example, see
http://www.thomas-distributing.com/batteries.htm

Ted

Cannot beat the New Discovery IQ9000 universal charger for AAs, Nicad,
NiMH, or alkaline. It uses a CEC1100 Microprocessor. 200:1 negative
pulse charge technology. 900ma charge current
  #8   Report Post  
Lewis Hartswick
 
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Default AA battary capacity, Ah (?)

Another point is peak current capability.
I believe NiMH have much higher current capability than alkiline.
...lew...
  #9   Report Post  
The Masked Marvel
 
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also see www.dpreview.com for digital camera info.

You'd be best to use NiMH's (typically 1600-2300 mA-hr in AA these days) and
a good inteligent charger and charge as slowly as practical (4-6 hrs vs. 1-2
hrs), as Alklines, while rated at 2400-2800 mA-hr (all at 10 hour rate???),
have higher internal impedence so run hotter and do not last nearly as long
as the NiMH's, not to mention you must throw them out vs. charge them.
Alternately look at cameras using propriatary Li-Ion batteries.

"Thor" wrote in message
...
On Wed, 09 Jul 2003 21:44:38 GMT, "Len Turnbow"


wrote:

(...)
there was thread here about battery life, and some of the new

technology
wrt digital cameras (eating AA Alkalines). i got suckered into

buying
another camera, and guess what, it really EATS AA'a, changing

batteries
would be a full time job.

the previous owner said he used 1600mah NMiH rechargeables and got
50-60 shots, some w/flash, some without the lcd on, but was generally
happy.

Question: before i even think about buying into an expensive set up
for only occaisional use, i need to know what is the actual capacity

of
the current crop of AA Alkaline battery. googling now, but find

nothing
beyond suggested uses on manufacturers sites.

Thanks! --Loren


Maybe you could check out rechargables?
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM

--Len

Also look at http://www.hosfelt.com/
They have higher capacity Ni-MH batteries in their printed catalog but not

shown
on the web page. Avoid quick chargers like the plague!

Thor



  #10   Report Post  
Remove SPAM From Address to Reply
 
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Ted Edwards wrote in message ...
Your friend was correct in recommending NiMH rechargeables,
you can get a decent set of 4 and a charger for about
$10 if you look for sales. Never need to pay more than
about $15.


Please don't do that! Those cheap chargers are either constant current
or timer terminated. Pay somewhat more and you can charge your
batteries whenever you feel like it without worrying about state of
charge. Ray-o-vac has a good charger but, personally, I like the Maha
line. My 204 isn't as versatile as some of the newer ones but it works
well. I paid Cdn$30 for it a couple years ago.
For example, see
http://www.thomas-distributing.com/batteries.htm
Ted


Ted,

That's partly correct. Yes, the cheap chargers are constant-
current, but no, they are not a problem. For most NiMH cells,
the "cheap" chargers are charging at a rate less than C/10, and
are no problem even if left plugged in all day. I bought my
sets from bydusa online over a year ago, and all cells are
still going strong. I paid $7.49 for the charger PLUS four
1800 mAH cells. Bought two sets, keep one charger at home and
the other in my camera bag with fresh cells in it. Makes a
good "battery holder".

Only if you want a "fast charger" do you need to step up to the
more expensive setup with microprocessor, and yes, you can get a
great one for less than $15. For 22.95 you can have the charger
and EIGHT NiMH cells (four AA and four AAA, I use the AAA in FRS
walkie-talkies). Model V-1000 package:

http://www.batteryspace.com

This thing works great, and it's dual-power, either AC or an
included cigarette-lighter adapter. I've also used it for
over a year. I keep this one in the console of my truck for
when I need to quick-charge cells, as it's not as small as the
slow charger that I keep in the camera bag.

best regards,

Martin


  #11   Report Post  
Dave Martindale
 
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(Remove SPAM From Address to Reply) writes:

Please don't do that! Those cheap chargers are either constant current
or timer terminated.


That's partly correct. Yes, the cheap chargers are constant-
current, but no, they are not a problem. For most NiMH cells,
the "cheap" chargers are charging at a rate less than C/10, and
are no problem even if left plugged in all day.


There are two different types of cheap charger. They're both constant
current with no detection of end of charge. One type uses a low enough
charge rate that a full charge takes 14 hours; that's what you're
talking about. If the batteries start out partially charged, not
completely discharged, they will be overcharged - but at such a low
current that it won't hurt them.

However, the *timed* cheap chargers use a higher current that will
recharge the batteries in about 5 hours. They are a problem because
they will properly recharge *only* a specific capacity of battery, and
*only* if it's fully discharged before charging. If the battery is
higher capacity than the charger is designed for, the timer will shut
off before full charge is reached. If the battery is the correct
capacity but isn't fully discharged, then the charger will overcharge
it, and with a current large enough to damage the battery.

So, avoid the timed chargers completely. 14-hour chargers are OK but
slow. Fast chargers with end-of-charge detection are OK and fast.

Dave
  #12   Report Post  
Ted Edwards
 
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Dave Martindale wrote:

There are two different types of cheap charger. They're both constant
current with no detection of end of charge. One type uses a low enough
charge rate that a full charge takes 14 hours; that's what you're
talking about. If the batteries start out partially charged, not
completely discharged, they will be overcharged - but at such a low
current that it won't hurt them.


From my reading, this seems to be somewhat cotroversial, some authors

and manufacturers claiming C/10, some C/20 and some saying even lower.
My MAHA 204 charges at C/60 after the end of the fast charge cycle.

It's probably on sacle of decreasing badness. :-)

Ted


  #13   Report Post  
Ted Edwards
 
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The Masked Marvel wrote:

Alternately look at cameras using propriatary Li-Ion batteries.


The problem with those are proprietary packs of any cell chemistry sell
at extorsionist prices. For the price of one spare Li-ion pack, I can
buy several sets of NiMH cells and, at todays performance levels, the
NiMH are very little behind similar volume Li-ion packs in performance.

Ted

  #16   Report Post  
Ted Edwards
 
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Dave Martindale wrote:

I never use anything but fast chargers now myself. But slow chargers
are better for the batteries than timed chargers, and so it's useful to
distinguish between them.


Agreed but a smart charger is so inexpensive considering how many safe
effective recharges you will get, not to mention the convenience.

Ted


  #17   Report Post  
Len S
 
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One by one, people will realize that NiMH never really lives up to
expectations. I have gone through a small fortune in cell phones,
digital cameras, and other doodads (OK, I'm a gadget hound) over the
last five years. Many developed useless NiMH batteries in only a few
months. Now I CAREFULLY check for Li-Ion when buying a new toy. I've
gotten years on my Li-Ion Notebook and camera without battery
replacement. There is a lot of BS circulating about NiMH (like any
other technical topic). From 1st hand experience:

1) NiMH does have memory effect (they may not call it that, but what
else can you call it when you are told to deep cycle a battery to
"fix" it?
2) NiMH self discharge is far worse than Li-Ion. I hate picking up
something that has been charged withing a few weeks and finding it
dead. If you have NiMH cells, get used to this.
3) Yes, Li-Ion cells are proprietary, but who cares if you can plug in
a camera and then use it for a few days. I've had one of those tiny
Casio camera for 6 months now and I can take pictures (on and off) for
2 weeks before it needs charging. Also some makers (I think Sony and
Konica) have cameras that use Li-Ion and AA Alkalines (of course you
could use AA NiMH if you like too)
4) NiMh performance may, on paper, be close to Li-ion, but in "real
world" electronic products, my experience is that NiMH is far behind.
Do not believe that you will get more charge-discharge cycles from
NiMH. Maybe in a contractor's cordless drill that normally gets run to
empty every time, But not in a camera, phone, or PDA, where it's very
normal to partially drain the battery, NiMH hates this, but Li-Ion is
very happy with this kind of use.
5) Notice that no decent notebook computer or cell phone uses NiMH any
more. These products now have brutal price pressure so the makers
would love to use cheaper batteries. They did use NiMH for a while,
but had to stop because the performance was just too crappy.

end of rant


LiIon also have the pseudo-advantage that the manufacturer *has* to
supply a decent charger for them. You can get equally good NiMH
chargers, but a lot of the NiMH chargers sold are junk. You have to do
a bit of research to get a good one.

Dave

  #18   Report Post  
Sofie
 
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Icoe:
Yes, actually.... the Radio Shack #23-405 is only for NiCad and NiMH....
NOT for LITHIUM.
and, yes, it is microprocessor controlled and is designed to specifically
sense the unique charging curves of NiCad or NiMH, switch selectable and
will shut off when it achieves full charge as detected by the chip...... or
failing that, it's backup timer will shut it off.
It is a nicely built unit and if used properly should work just fine....
the business about charging only fully discharged cells applies mainly to
NiCad .... by fully discharging them, the "memory effect" is negated. You
really do not want to fully discharge NiMH every time you charge them....
and you don't have to.... there is no memory effect to worry about.....
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------------------------------


"lcoe" wrote in message
news:nzxPa.34650$ye4.26674@sccrnsc01...

Ted, or anyone, i bot a RShack "Auto Sensing" model (for ni-cad and

lithium).
the manual and box says, "automatically senses full charge and shuts off".
further, in the manual it says, '`...charge only fully discharged

cells...'

another feature is a "backup" fixed timer, 1.5hr for nicad, 2.0 for lith.
it's RS model 23-405, 50% off recently. it's heavy, brick shaped, but
is it really fully automatic? Thanks! --Loren






  #19   Report Post  
lcoe
 
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In rec.crafts.metalworking Sofie wrote:
Icoe:
Yes, actually.... the Radio Shack #23-405 is only for NiCad and NiMH....
NOT for LITHIUM.


yes, i mis-spoke, thanks for noticing.

and, yes, it is microprocessor controlled and is designed to specifically
sense the unique charging curves of NiCad or NiMH, switch selectable and
will shut off when it achieves full charge as detected by the chip...... or
failing that, it's backup timer will shut it off.
It is a nicely built unit and if used properly should work just fine....
the business about charging only fully discharged cells applies mainly to
NiCad .... by fully discharging them, the "memory effect" is negated. You
really do not want to fully discharge NiMH every time you charge them....
and you don't have to.... there is no memory effect to worry about.....
-- Best Regards, Daniel Sofie Electronics Supply & Repair


do you, or anyone know the cutoff voltage for the charge cycle? was thinking
of testing it by charging some partially discharged alkalines.

i see some newer chargers on-line that have a switch selectable "dis-charge"
then/charge mode. i believe it works for either type battery. Thanks! --Loren
`
--------------------------------------------



"lcoe" wrote in message
news:nzxPa.34650$ye4.26674@sccrnsc01...


Ted, or anyone, i bot a RShack "Auto Sensing" model (for ni-cad and

lithium).
the manual and box says, "automatically senses full charge and shuts off".
further, in the manual it says, '`...charge only fully discharged

cells...'

another feature is a "backup" fixed timer, 1.5hr for nicad, 2.0 for lith.
it's RS model 23-405, 50% off recently. it's heavy, brick shaped, but
is it really fully automatic? Thanks! --Loren






  #20   Report Post  
Sofie
 
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Icoe:
I would very strongly suggest that you NOT put alkaline batteries in your
Radio Shack #23-405 charger..... it is only designed for NiCads and NiMH.
DO NOT put alkalines in ANY charger not specifically designed for
alkalines..... they may explode or at the very least, get hot and make a
hell of a mess.
The cut-off voltage and charging curve is different for NiCad versus NiMH
..... that is why the charger has a 2 position selection switch..... make
certain it is set correctly for the type of battery you are charging....
notice that there is NOT a 3rd selection position for Alkaline...... do NOT
attempt to recharge alkaline batteries in this charger.
The automatic discharge and then recharge feature of some chargers and
reconditioners was meant mainly for NiCads..... to help minimize the "memory
effect" ...... not really needed for NiMH although there are those that say
it helps and others that say that regular deep cycling of NiMH is not
beneficial or even good for the battery..... my experience suggests the
latter.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------



"lcoe" wrote in message
news:J1BPa.36050$H17.10762@sccrnsc02...

do you, or anyone know the cutoff voltage for the charge cycle? was

thinking
of testing it by charging some partially discharged alkalines.

i see some newer chargers on-line that have a switch selectable

"dis-charge"
then/charge mode. i believe it works for either type battery.

Thanks! --Loren
`






  #21   Report Post  
Ted Edwards
 
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lcoe wrote:

Ted, or anyone, i bot a RShack "Auto Sensing" model (for ni-cad and lithium).
the manual and box says, "automatically senses full charge and shuts off".
further, in the manual it says, '`...charge only fully discharged cells...'


That's a bad sign. A smart charger should be detecting end of charge by
watching for delta-V (a slight drop in voltage). I am concerned that
they say NiCd and lithium (what lithium?) but do not mention NiMH.

another feature is a "backup" fixed timer, 1.5hr for nicad, 2.0 for lith.
it's RS model 23-405, 50% off recently. it's heavy, brick shaped, but
is it really fully automatic?


Personally, I would not go for it. Sounds wrong.

Ted


  #22   Report Post  
Ted Edwards
 
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Len S wrote:

One by one, people will realize that NiMH never really lives up to
expectations.


Actually, all 4 sets of 4 (116 cells) NiMH AA's that I have have
exceeded expectations. Sounds like you may have tried very early cells.

gotten years on my Li-Ion Notebook and camera without battery


Well, mine died in two years. This is about average life from what I
have read although a few have done better.

replacement. There is a lot of BS circulating about NiMH (like any
other technical topic).


Li-ion suffers from the same thing such as the statements below

From 1st hand experience:
1) NiMH does have memory effect (they may not call it that, but what
else can you call it when you are told to deep cycle a battery to
"fix" it?


There are several effects in batteries that are eroneously called memory
effect. Li-ion suffers from some of these too.

2) NiMH self discharge is far worse than Li-Ion.


This is true but

something that has been charged withing a few weeks and finding it
dead. If you have NiMH cells, get used to this.


Either you are storing your units in a *very* warm place or your
appliance has an ureasonably high standby current. (This is not all
that infrequent.) Over the winter I do not get out for as many walks as
I would like (asthma) so my GPS sees much less use. I changed batteries
on Feb 2, recharged the dead set and left them in my desk drawer. On
Mar 7, the batteries in GPS died so I switched sets *without* recharging
the set from the drawer. These were in use until Mar 20 (almost two
months since being charged) and delivered their usual approx. 14 hours
running time. I suggest you check the standby current on your
instruments.

4) NiMh performance may, on paper, be close to Li-ion, but in "real
world" electronic products, my experience is that NiMH is far behind.


As you can see, I'm questioning your "real world" experience. My
*measurements* corrolate well with Dave Etchell's in
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM and the data in
http://www.dp-now.com/index.html

Do not believe that you will get more charge-discharge cycles from
NiMH. Maybe in a contractor's cordless drill that normally gets run to
empty every time, But not in a camera, phone, or PDA, where it's very
normal to partially drain the battery, NiMH hates this, but Li-Ion is
very happy with this kind of use.


Sorry, but this is patently false for NiMH being charged with a smart
charger.

5) Notice that no decent notebook computer or cell phone uses NiMH any
more.


These products also have a high status factor. The average business
persons notebok gets replaced because it is "out of date" not because it
doesn't do the job it was purchased for. Li-ion is a status item.

Ted

  #23   Report Post  
Dave Martindale
 
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lcoe writes:

do you, or anyone know the cutoff voltage for the charge cycle? was thinking
of testing it by charging some partially discharged alkalines.


There isn't a "cutoff voltage". NiMH and NiCd cells are charged while
monitoring voltage over time. As the cells reach full charge, the
terminal voltage rate of change goes to zero, and then negative (i.e.
the voltage *drops*). This is what the chargers sense. They may also
sense the rapid rise in temperature at end of charge.

Don't put alkalines in this charger. Alkalines won't accept high charge
currents, and they'll probably burst or leak.

Dave
  #24   Report Post  
Dave Martindale
 
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(Len S) writes:
One by one, people will realize that NiMH never really lives up to
expectations. I have gone through a small fortune in cell phones,
digital cameras, and other doodads (OK, I'm a gadget hound) over the
last five years. Many developed useless NiMH batteries in only a few
months.


How did you charge them? Did you use a good fast charger?

I've had a number of NiMH cells fail, but they were 5 years old or
more.

1) NiMH does have memory effect (they may not call it that, but what
else can you call it when you are told to deep cycle a battery to
"fix" it?


There are several use-related and charging-related effects that may
affect the apparent capacity of a NiMH cell. You don't need to learn
about them if you don't want, but that doesn't justify calling it
"memory effect" when it's something else.

From what I've read (the Cadex book), NiMH cells should be given a full
discharge once a month or once every couple of months to keep the nickel
electrode in good shape. If you recharge every day, that's a tiny
fraction of the charge cycles.

2) NiMH self discharge is far worse than Li-Ion. I hate picking up
something that has been charged withing a few weeks and finding it
dead. If you have NiMH cells, get used to this.


NiMH self-discharge *is* higher than LiIon. However, it takes many months
for them to be dead. In a few weeks, you might see 20 or 30% reduction
in capacity. If your cells are dead in "a few weeks", either you have
bad cells, or they're in a device that puts a constant load on them.
For example, many electronic devices with electronic "power" switches
actually draw current when "off".

When I know I'm going to use a device with NiMH batteries, and I haven't
used it for a while, I'll just pop the batteries into a fast charger.
They're back to *full* charge in 15 minutes, ready to use. It's pretty
seldom that I don't have 15 minutes advance warning of needing a
battery-powered device.

3) Yes, Li-Ion cells are proprietary, but who cares if you can plug in
a camera and then use it for a few days.


Some people care what a spare battery costs. Some people like having a
"pool" of NiMH cells that they can use in any device. Some people like
having a choice of chargers.

5) Notice that no decent notebook computer or cell phone uses NiMH any
more. These products now have brutal price pressure so the makers
would love to use cheaper batteries. They did use NiMH for a while,
but had to stop because the performance was just too crappy.


I think this had more to do with weight. A LiIon battery storing a
certain amount of energy is about half the weight of an equivalent
NiMH battery. The battery is a significant chunk of the weight of
either a cellphone or laptop.

It just so happens that I have a laptop computer with a LiIon battery.
The battery is nearly dead, and provides only 5-10 minutes of running
time. The battery cannot be taken apart and rebuilt with new cells; I
have to buy a new one. (New ones cost CDN$200-300!) This doesn't mean
that all LiIon batteries are bad, but it does provide a counterexample
to the "LiIon batteries are always wonderful" message.

Dave
  #25   Report Post  
Dave Martindale
 
Posts: n/a
Default AA battary capacity, Ah (?)

lcoe writes:

so i popped them in and the camera fired up fine, and i reviewed pictures
taken w/these same batteries. then i went to 'record', it tried, but
shutdown. again, sameo, sameo.


This is really just demonstrating that alkalines aren't suitable for
your digital camera - too much internal resistance.

Rechargeable alkalines, even on their first use, are worse than
single-use ones, Later discharges get worse yet because internal
resistance increases. I don't expect single-use alkalines that have
been recharged are any different in this respect.

the choice still remains to install fresh alkalines, assuming the
balance of the battery cap. could be utilized, and if i am willing
to put up with the intemittant operation of the camera. for now,
it's going to be Ni-mh, but i will not be able to resist further
testing.


Forget the alkalines. You've demonstrated that they're useless except
as an absolute last resort. Use NiMH for day to day use. Buy a set of
single-use lithium AAs for backup if you can't always be sure of having
enough NiMH batteries for a trip.

Dave


  #26   Report Post  
Bob Kos
 
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Default AA battary capacity, Ah (?)

Right on the money. Heat kills batteries. Cheap chargers overheat the
batteries. The Maha chargers work nice for reasonable cost. I have NiMH
batteries that still work well after 5 years thanks to the TLC they get in
my cheapie Maha charger. Thomas Distributing is the place to get 'em.

Speaking of heat, you should use caution in using lithium AA throwaway
batteries. They apparently get quite hot during heavy discharge cycles. So
much so that my Olympus D-600L's warranty would be voided if those batteries
were used in it.

Ted Edwards wrote in message ...

Please don't do that! Those cheap chargers are either constant current
or timer terminated. Pay somewhat more and you can charge your
batteries whenever you feel like it without worrying about state of
charge. Ray-o-vac has a good charger but, personally, I like the Maha
line. My 204 isn't as versatile as some of the newer ones but it works
well. I paid Cdn$30 for it a couple years ago.
For example, see
http://www.thomas-distributing.com/batteries.htm

Ted




  #27   Report Post  
Old Nick
 
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Default AA battary capacity, Ah (?)

On Fri, 11 Jul 2003 19:34:24 +0000 (UTC), (Dave
Martindale) wrote something
.......and in reply I say!:

PMFJI. You sound as if you are addressing the questions I have.

I have a couple of little Uniden walkie-talkies, that take 4 X AAA
cells. They chew out the cells fairly fast, so I bought NiCds. No go.
The radios appear to have trouble dealing with the lower voltage. I
reckon they are trying to grab max volts to get Tx power up, and
probably should have had an extra battery. Rechargeable ALkalines
worked fine, but as you say deteroriate rapidly.

Sorry. Question. Are NiMH cells better in this regard? I am ringing
battery houses, and one guy said they were. I assume this would be
because they have lower internal resistance. Is this so? I got the
impression the guy knew more about _batteries_ than I do, but less
about electrical theory G

Next G. One shop had several AH capacities, at different prices
(actually they were the only ones to explain this, and will get my
custom). Are there any advantages/disadvantages to getting the lower
capacities, if this means they get discharged better etc?

Thanks for any help. Sick of buying expensive "special" chargers that
then gather dust.

This is really just demonstrating that alkalines aren't suitable for
your digital camera - too much internal resistance.


************************************************** ****************************************
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
!!
")
_/ )
( )
_//- \__/
  #28   Report Post  
Dave Martindale
 
Posts: n/a
Default AA battary capacity, Ah (?)

(Old Nick) writes:

I have a couple of little Uniden walkie-talkies, that take 4 X AAA
cells. They chew out the cells fairly fast, so I bought NiCds. No go.
The radios appear to have trouble dealing with the lower voltage. I
reckon they are trying to grab max volts to get Tx power up, and
probably should have had an extra battery. Rechargeable ALkalines
worked fine, but as you say deteroriate rapidly.


Sounds like the radio is poorly designed. Alkaline cells start at 1.5
volts, but drop pretty much continuously in voltage as they are drained.
Depending on the load, a device needs to operate properly down to 1 V
per cell (light load) to 0.8 V per cell (heavy load) in order to get
most of the energy out of alkalines. So a properly-designed radio
powered by 4 alkaline cells should tolerate 6 V in, but work properly
all the way down to 4 V. NiCd and NiMH cells provide about 1.2 V over
nearly their entire discharge time, over a wide range of load. Thus,
4 cells will provide 4.8 V and the radio *should* work fine.

If the radio doesn't work on NiCds, and the NiCds were in fact all good,
then it just doesn't operate properly at 4.8 V. If it works at 6 V but
not at 4.8 V, it will start working OK on alkalines, but stop working
when the alkalines are still half-full.

Sorry. Question. Are NiMH cells better in this regard? I am ringing
battery houses, and one guy said they were. I assume this would be
because they have lower internal resistance. Is this so? I got the
impression the guy knew more about _batteries_ than I do, but less
about electrical theory G


NiMH is not better than NiCd in this respect. NiMH actually have higher
internal resistance than NiCd, though still far below alkalines. If
NiCds don't work, NiMH aren't likely to either.

Next G. One shop had several AH capacities, at different prices
(actually they were the only ones to explain this, and will get my
custom). Are there any advantages/disadvantages to getting the lower
capacities, if this means they get discharged better etc?


Lower capacity cells may just be older. But they may also have lower
internal resistance. You can't really tell without measuring. I
wouldn't pay much of a premium for exceptionally high capacity.

Dave
  #29   Report Post  
Jim K
 
Posts: n/a
Default AA battary capacity, Ah (?)

Like everything else, your mileage will vary. I bought a Toshiba
digital camera around 4 years ago and bought a set of NiMH with
charger for around $25. I'm still using the same set and have taken
thousands of pictures.

On 11 Jul 2003 00:41:15 -0700, (Len S) wrote:

One by one, people will realize that NiMH never really lives up to
expectations. I have gone through a small fortune in cell phones,
digital cameras, and other doodads (OK, I'm a gadget hound) ov

snipped
  #30   Report Post  
jakdedert
 
Posts: n/a
Default AA battary capacity, Ah (?)

All the Motorola FRS radios (that I'm familiar with) use three AA cells.
All of their literature states that alkalines or Nimhs *must* be used.
According to Motorola, NiCads are not acceptable.

jak

"Dave Martindale" wrote in message
...
(Old Nick) writes:

I have a couple of little Uniden walkie-talkies, that take 4 X AAA
cells. They chew out the cells fairly fast, so I bought NiCds. No go.
The radios appear to have trouble dealing with the lower voltage. I
reckon they are trying to grab max volts to get Tx power up, and
probably should have had an extra battery. Rechargeable ALkalines
worked fine, but as you say deteroriate rapidly.


Sounds like the radio is poorly designed. Alkaline cells start at 1.5
volts, but drop pretty much continuously in voltage as they are drained.
Depending on the load, a device needs to operate properly down to 1 V
per cell (light load) to 0.8 V per cell (heavy load) in order to get
most of the energy out of alkalines. So a properly-designed radio
powered by 4 alkaline cells should tolerate 6 V in, but work properly
all the way down to 4 V. NiCd and NiMH cells provide about 1.2 V over
nearly their entire discharge time, over a wide range of load. Thus,
4 cells will provide 4.8 V and the radio *should* work fine.

If the radio doesn't work on NiCds, and the NiCds were in fact all good,
then it just doesn't operate properly at 4.8 V. If it works at 6 V but
not at 4.8 V, it will start working OK on alkalines, but stop working
when the alkalines are still half-full.

Sorry. Question. Are NiMH cells better in this regard? I am ringing
battery houses, and one guy said they were. I assume this would be
because they have lower internal resistance. Is this so? I got the
impression the guy knew more about _batteries_ than I do, but less
about electrical theory G


NiMH is not better than NiCd in this respect. NiMH actually have higher
internal resistance than NiCd, though still far below alkalines. If
NiCds don't work, NiMH aren't likely to either.

Next G. One shop had several AH capacities, at different prices
(actually they were the only ones to explain this, and will get my
custom). Are there any advantages/disadvantages to getting the lower
capacities, if this means they get discharged better etc?


Lower capacity cells may just be older. But they may also have lower
internal resistance. You can't really tell without measuring. I
wouldn't pay much of a premium for exceptionally high capacity.

Dave






  #31   Report Post  
Len S
 
Posts: n/a
Default AA battary capacity, Ah (?)

Ted Edwards wrote in message ...
Len S wrote:

.......Sounds like you may have tried very early cells.

You may be right, but I've been reluctant to give them a chance for
the last few years.


gotten years on my Li-Ion Notebook and camera without battery


Well, mine died in two years. This is about average life from what I
have read although a few have done better.

I would agree again. It's just that my NiMH results have never been
that good.

Li-ion suffers from the same thing such as the statements below

From 1st hand experience:
1) NiMH does have memory effect (they may not call it that, but what
else can you call it when you are told to deep cycle a battery to
"fix" it?

There are several effects in batteries that are eroneously called memory
effect. Li-ion suffers from some of these too.

OK, maybe I got on a roll here. But I have never had to "condition"
LiIon cells.


2) NiMH self discharge is far worse than Li-Ion.

This is true but

something that has been charged withing a few weeks and finding it
dead. If you have NiMH cells, get used to this.


Either you are storing your units in a *very* warm place or your
appliance has an ureasonably high standby current.

Could be (never measured)

4) NiMh performance may, on paper, be close to Li-ion, but in "real
world" electronic products, my experience is that NiMH is far behind.


As you can see, I'm questioning your "real world" experience. My
*measurements* corrolate well with Dave Etchell's in
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM and the data in
http://www.dp-now.com/index.html

I must defer to the tests. But I don't like the idea of swapping sets
of cells for something like a digital camera. You pop out the
discharged set for charging. Then pop in a set that was charged a
while back. Now you don't know how full these cells are because they
have been self discharging after their charger terminated a long time
ago. I prefer embedded chargers.

Do not believe that you will get more charge-discharge cycles from
NiMH. Maybe in a contractor's cordless drill that normally gets run to
empty every time, But not in a camera, phone, or PDA, where it's very
normal to partially drain the battery, NiMH hates this, but Li-Ion is
very happy with this kind of use.


Sorry, but this is patently false for NiMH being charged with a smart
charger.

I disagree. This is the 2nd most significant difference between the 2
cell chemistries. Low self discharge being #1

5) Notice that no decent notebook computer or cell phone uses NiMH any
more.

These products also have a high status factor. The average business
persons notebok gets replaced because it is "out of date" not because it
doesn't do the job it was purchased for. Li-ion is a status item.

I again don't agree. Li-Ion would not be a status symbol if there were
no benefit. Do you think the average user had any idea what NiMH or
Li-Ion was before all this stuff started? Of course not. If (the
cheaper) NiMH cells worked adequately, cell phones and Notebook would
be using them and hyping NiMH instead. The price competition on these
products is ruthless. They look for ways to cut $0.05 from cost.

Now the one key point that actually makes us both mostly correct is
that you are talking about outboard chargers and I am talking about
embedded chargers. You most like are running your cells through full
cycles so your batteries are happy. I used my old cell phone a little
bit every day and then plugged it in at night. The battery died (had
about 5 minutes capacity) in 2-3 months. Now a days you have zero
chance of getting a good NiMh charger built into something because a
*good* NiMH charger actually costs more than a good Li-Ion one and
almost offsets the battery cost.
  #32   Report Post  
Dave Martindale
 
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Default AA battary capacity, Ah (?)

"jakdedert" writes:
All the Motorola FRS radios (that I'm familiar with) use three AA cells.
All of their literature states that alkalines or Nimhs *must* be used.
According to Motorola, NiCads are not acceptable.


That's not true of the T6210. In the battery installation section, it
just says "AA batteries" or a special NiMH pack sold by Motorola. It
doesn't specify what kind of AA batteries.

Later in the manual, it describes how you can change the battery meter
voltage thresholds. The two settings are "A" for alkaline and "n" for
"NiMH or NiCad rechargeable". That's a direct quote from the manual.
So it's clearly intended to work with NiCd cells.

The Motorola NiMH pack is somewhat weird - its capacity is only 550 mAH.
I wonder if they use 4 AAA cells in it to get 4.8 V for higher transmit
power (but short battery life). It also has contacts that mate with
charging contacts on the battery compartment cover, which in turn mate
with contacts on the Motorola charger. This ensures that only the
Motorola rechargeable pack can be charged inside the radio.

Dave
  #33   Report Post  
Ted Edwards
 
Posts: n/a
Default AA battary capacity, Ah (?)

lcoe wrote:

Ted, or anyone, i bot a RShack "Auto Sensing" model (for ni-cad and lithium).
the manual and box says, "automatically senses full charge and shuts off".
further, in the manual it says, '`...charge only fully discharged cells...'


I replied to this but don't see it and my ISP has been having the
nasties so:

I wouldn't trust it but YMMV. First off, they don't mention delt-V
termination or NiMH. Second, there should be no need to fully discharge
cells before charging if it were truly a smart charger.

another feature is a "backup" fixed timer, 1.5hr for nicad, 2.0 for lith.
it's RS model 23-405, 50% off recently. it's heavy, brick shaped, but
is it really fully automatic?


I don't think so and wouldn't trust it but I haven't personally seen
it. I *know* the Maha's are good.

Ted

  #34   Report Post  
Sofie
 
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Default AA battary capacity, Ah (?)

Old Nick......
Adding the extra NiCad cell as you suggested will give you a total of 4.8
V.... very close to what 3 fresh alkaline batteries will put out. An
eloquent solution that I have seen in some consumer equipment over the years
is to use (2) AAA cells and (2) 1/2AAA cells. The 1/2 cells obviously
won't have the capacity of a larger full size AAA cell, but the radio will
operate correctly with the voltage boost....... and all the batteries can
fit in the radio's battery compartment without the need for "ugly"
modifications and "add ons".
The "half" cells in the AAA size can be difficult to find but they are
available.......
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
-----------------------------



  #35   Report Post  
jakdedert
 
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I'm sorry. I've got so many of these--of several different models--that I
can't pull up just where I saw that info. I checked to be sure, because I
have NiCds I could be using. Nimh's work great, and alkaline usage is
acceptable...unless I have a crew of 11 guys all trying to keep in touch.
Then I go through a case of them in a week or so.

I'm sure I saw this info somewhere...it may have been one particular model.
The 280 manual (only one which I was able to put my hands on easily) doesn't
mention NiCd's at all...just rechargeable alk's. We've got 280's, 250's,
6220's, FR-60's--among others.

jak

"Dave Martindale" wrote in message
...
"jakdedert" writes:
All the Motorola FRS radios (that I'm familiar with) use three AA cells.
All of their literature states that alkalines or Nimhs *must* be used.
According to Motorola, NiCads are not acceptable.


That's not true of the T6210. In the battery installation section, it
just says "AA batteries" or a special NiMH pack sold by Motorola. It
doesn't specify what kind of AA batteries.

Later in the manual, it describes how you can change the battery meter
voltage thresholds. The two settings are "A" for alkaline and "n" for
"NiMH or NiCad rechargeable". That's a direct quote from the manual.
So it's clearly intended to work with NiCd cells.

The Motorola NiMH pack is somewhat weird - its capacity is only 550 mAH.
I wonder if they use 4 AAA cells in it to get 4.8 V for higher transmit
power (but short battery life). It also has contacts that mate with
charging contacts on the battery compartment cover, which in turn mate
with contacts on the Motorola charger. This ensures that only the
Motorola rechargeable pack can be charged inside the radio.

Dave






  #36   Report Post  
Eastburn
 
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Default AA battary capacity, Ah (?)

Remember - NiCad are 1.25 volts per cell. To low for some electronics
to function when in a higher voltage circuit.

Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
  #37   Report Post  
lcoe
 
Posts: n/a
Default AA battary capacity, Ah (?)

In rec.crafts.metalworking Eastburn wrote:
Remember - NiCad are 1.25 volts per cell. To low for some electronics
to function when in a higher voltage circuit. Martin


1.2, right? also, i now find that the NiMH are also 1.2(!). --Loren

--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

  #40   Report Post  
jakdedert
 
Posts: n/a
Default AA battary capacity, Ah (?)

My old Olympus D-320L digicam goes through alkalines like crazy...but when
they won't work in the camera anymore, they still have plenty of capacity
for flashlights and the like.

I'll have to measure the open circuit voltage the next time I change them,
IIRC it was something like 1.3 volts.

jak

"Dave Martindale" wrote in message
...
(GregS) writes:

On the other hand, there is a GE discount CB walkie-talkie that has been

sold
in many discount outlets. It uses a fixed amount of cells. It will ONLY
work with alkalines.
It NEEDS the extra voltage for the thing to output any decent power, 5
watts, where
the 1.2 volt cells will cause it to output 1/10th proper power level or

500mw.

Which means that it will use half or less of the energy in one set of
alkaline cells before you have to replace them with new ones.

This certainly fits my definition of "junk".

Dave




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