Charging batteries inside an appliance

[David L. Jones]

Pete wrote:

David L. Jones wrote:

Now this is just playing around with words and specific numbers.

No it's not - the figures are from your data sheets.

Yes, a NiMH cell may have its service life reduced by a normal 0.1C
charger, due to overcharge, but you are talking specific values now.

Yes, specific because C10 is the typical rate used to trickle charge NiCd.

See my comment below.

It is possible to "trickle charge" a NiMH cell (at some rate between
0.1C and the "maintenance" charge rate for arguments sake) to
eventually fully charge a NiMH cell and not damage it. That's what I've
been saying all along.

Surely now *you're* just "playing with words and specific numbers"

So you finally admit that a charge rate somewhere between that of a
suggested "maintenance" rate and a typical 0.1C rate will be able to
(eventually) charge a NiMH safely?

Even the maintenance charge rate suggested by the manufacurers is above
the actual self discharge rate of the battery, so the battery is
receiving charge. It's just that rate of charge is so low that the
battery does not damage itself through pressure or temperature
increase. They say that 0.1C is slightly too high and may cause some
damage. It doesn't take a genious to then realise realise that a rate
somewhere between this is a good compromise. Real practical testing
shows this to be true.

Even if you do "damage" a cell and reduce it's service life, it's often
not a big deal, you still get very effectice service use for your
money. You can abuse them a little and get away with it, it's done all
the time with the cheap timer based chargers.

Your original statement was this:

There is essentially no difference between the two chargers.
You can use a Nicd charger to charge NiMH's.

Patently, that's untrue. And now you appear to even be agreeing that
you need to charge at a specific rate.

It's not a "specific rate", in practice, anything under 0.1C is fairly
safe and will work just fine.
You do realise that a 0.1C NiCd rate is *not* a 0.1C rate for NiMH
don't you?
A typical old NiCD charger has a timed charge at maybe 0.2C and then a
trickle charge rate of 0.1C, but that is for a typical 600mAh NiCd. An
NiMH cell is now 2500mAh, so that equates to 0.05C and 0.025C for the
NiMH. That should be perfectly safe for the OP's application - heaven
forbid we actually get back onto the OP's original topic to which you
haven't actually contributed anything directly.

You can dick around with exact C numbers all you like, the fact is in
practice you can do it sucessfully. I know, I've done it myself.

The fact is, unless you "dick around with exact C numbers", you're in
danger of overcharging NiMh cells, and therefore reducing their service
life. Which is exactly what your data sheets all say, many times over.

As I've said from the start, if you keep it under 0.1C you shouldn't
have any problems.
There are many other variables that effect the service life of a NiMH,
a slight overcharge due to trickle charging, even at 0.1C rate simply
isn't a big deal, get over it!

Build some real systems, test some real batteries, you'll find out.

I've probably built more that you can imagine, Dave.

None at under 0.1C obviously!

Dave

 

[Pete]

David L. Jones wrote:

You do realise that a 0.1C NiCd rate is *not* a 0.1C rate for NiMH
don't you?

Now you're frightening me, Dave. 0.1C is 0.1C is 0.1C for whatever it's
referring to. C is the rated capacity of the cell, it doesn't mean
anything else, and it has nothing to do with the chemistry.

0.1C for one cell is the same as 0.1C for another cell of the same
capacity, and it's different to 0.1C for another cell of a different
capacity.

Do you have this same problem with understanding decibels?

A typical old NiCD charger has a timed charge at maybe 0.2C and then a
trickle charge rate of 0.1C, but that is for a typical 600mAh NiCd.

I think you're demonstrating here that you don't understand what C
means, Dave.

As I've said from the start, if you keep it under 0.1C you shouldn't
have any problems.

No, what you said from the start was that NiCd and NiMh chargers were
the same, and that it was fine to use one for the other. And that's
wrong. The 0.1C business came into it much later, as you started to try
to qualify your ill-informed original statement.

There are many other variables that effect the service life of a NiMH,
a slight overcharge due to trickle charging, even at 0.1C rate simply
isn't a big deal, get over it!

Dave, there's a right way to do things, and a wrong way. If you're
happy with your "she'll be right mate" way of doing things, then that's
something that the facts are unlikely to change.

None at under 0.1C obviously!

At least I understand what 0.1C *means* - the quote from you at the top
of this message shows that you don't.

Peter

 

[David L. Jones]

Pete wrote:

David L. Jones wrote:

You do realise that a 0.1C NiCd rate is *not* a 0.1C rate for NiMH
don't you?

Now you're frightening me, Dave. 0.1C is 0.1C is 0.1C for whatever it's
referring to. C is the rated capacity of the cell, it doesn't mean
anything else, and it has nothing to do with the chemistry.

0.1C for one cell is the same as 0.1C for another cell of the same
capacity, and it's different to 0.1C for another cell of a different
capacity.

Do you have this same problem with understanding decibels?

A typical old NiCD charger has a timed charge at maybe 0.2C and then a
trickle charge rate of 0.1C, but that is for a typical 600mAh NiCd.

I think you're demonstrating here that you don't understand what C
means, Dave.

You have made yourself look like a complete and utter goose Peter. See
below.

As I've said from the start, if you keep it under 0.1C you shouldn't
have any problems.

No, what you said from the start was that NiCd and NiMh chargers were
the same, and that it was fine to use one for the other. And that's
wrong. The 0.1C business came into it much later, as you started to try
to qualify your ill-informed original statement.

Rubbish. My post stands correct. A 0.1C 600mAh NiCd charger can be used
on a 2500mAh NiMH with no problems.

There are many other variables that effect the service life of a NiMH,
a slight overcharge due to trickle charging, even at 0.1C rate simply
isn't a big deal, get over it!

Dave, there's a right way to do things, and a wrong way. If you're
happy with your "she'll be right mate" way of doing things, then that's
something that the facts are unlikely to change.

None at under 0.1C obviously!

At least I understand what 0.1C *means* - the quote from you at the top
of this message shows that you don't.

Peter

You sniped the explaining paragraph in my post to screw things around
completely. What the hell are you trying to prove?
I know perfectly well what C means, you know it, and my posts show
this.

Here is my full post AGAIN just in case you didn't understand it the
first time:
"You do realise that a 0.1C NiCd rate is *not* a 0.1C rate for NiMH
don't you?
A typical old NiCD charger has a timed charge at maybe 0.2C and then a
trickle charge rate of 0.1C, but that is for a typical 600mAh NiCd. An
NiMH cell is now 2500mAh, so that equates to 0.05C and 0.025C for the
NiMH. That should be perfectly safe for the OP's application "

Do you see and comprehend that second paragragh? I was qualifying the
first paragraph.

*of course* 0.1C is the same for both NiCd and NiMH or any other, I did
not say or imply that it was not (unless you stupidly take my post out
of context). My following paragraph which you deliberatly snipped out
shows that.

This is a *real* NiCd charger we are talking about here that charges at
0.1C rate *for a NiCd cell*. For a 600mA NiCd cell that is a 60mA
charge current. If you connect this *same charger* to a 2500mAh NiMH
cell it is no longer a 0.1C charge rate, it becomes 0.024C *for the
NiMH cell*. You know, basic math, 60mA/2500mAh, it's not that hard, try
it.
The charger doesn't magically know it's got a NiMH cell in there with a
greater capacity and adjust the current to 0.1C for the NiMH.
This is what the OP wants to know, can an old NiCd charger be used on a
new NiMH cell, the answer is yes. But of course you aren't contributing
to the actual thread and helping the OP, you are just being silly.

Stop these stupid context and misquote games, you really are making
yourself look like a total goose.

You admit that you have no experience with NiMH chargers working at
less than 0.1C, so why don't you just bow out?

Dave

 

[richardghole@yahoo.com]

I got one labeled "lenmar nomem pro" it's a fast-charger with a 12V plug
pack and a car adaptor, it'll charge 1000maH AA nicads in 100 minutes and
NiMHs in proportianately longer (and shut off automatically)

--

Bye.
Jasen

Hi Jason

Thanks for your letter.

I thought that a rapid charger could possibly damage the camera or
overheat it and that a very slow rate of charging would be best used.
Do you think so?

What is the output voltage and current of the charger you refer to?

Your help is appreciated,
Regards Richard.

 

[Pete]

David L. Jones wrote:

Rubbish. My post stands correct. A 0.1C 600mAh NiCd charger can be used
on a 2500mAh NiMH with no problems.

Except that that's *not* what you said - you gave no figures, and made
the general statement that any NiCd charger could be used on any NiMh cell.

"You do realise that a 0.1C NiCd rate is *not* a 0.1C rate for NiMH
don't you?

A 0.1C NiCd rate *IS* a 0.1C NiMh rate, Dave. How can it not be?

If what you really meant to say is that 0.1C for a 600mA cell is not the
same as 0.1C for a 2500mH cell, then that would be correct. But the
chemistry itself has no bearing on what 0.1C means, so your statement is
just plain silly.

*of course* 0.1C is the same for both NiCd and NiMH or any other

Then why did you ask me (and I quote) "You do realise that a 0.1C NiCd
rate is *not* a 0.1C rate for NiMH don't you?"

Dave, you appear to be trying to prove something. I just wish I
understood what it was.

This is a *real* NiCd charger we are talking about here that charges at
0.1C rate *for a NiCd cell*. For a 600mA NiCd cell that is a 60mA
charge current. If you connect this *same charger* to a 2500mAh NiMH
cell it is no longer a 0.1C charge rate, it becomes 0.024C *for the
NiMH cell*. You know, basic math, 60mA/2500mAh, it's not that hard, try
it.

At last - you're making sense! However, to do so, you've had to start
quoting numbers rather than making silly generalisations. But when I
quote numbers, you accuse me of all sorts of things.

This is what the OP wants to know, can an old NiCd charger be used on a
new NiMH cell, the answer is yes.

The original poster said nothing about "old", that's something you
added. The original poster, as I recall, asked a general question,
without specifying anything about the charger other than that it was a
NiCd changer.

You then gave a general answer, without knowing *any* of the details of
the charger. That general answer was wrong, *because* you didn't know
any of the details.

Now you're saying that a *specific* NiCd charger in a *specific*
situation, will work. I agree.

However, we've taken a bloody long time to get here, and there's been an
awful lot of waffle, and some *bad* information that some people may
take as fact because of the way it was presented, *without* any detail.

The devil's in the detail, Dave - you can't generalise.

But of course you aren't contributing
to the actual thread and helping the OP, you are just being silly.

Your contribution started with a bad generalisation, then progressed to
a few more bad generalisations, some strange advice that 0.1C for NiCd
chemistry was different to 0.1C for NiMh chemistry, and other similarly
silly generalisations.

Finally, though, *because* I took you to task on that generalisation,
we've finally arrived at good advice. And that's that a specific charge
rate for a specific NiCd charger probably wouldn't damage a NiMh cell.

That's *vastly* different to your original claim that any NiCd charger
is suitable to charge NiMh cell.

Stop these stupid context and misquote games, you really are making
yourself look like a total goose.

Every quote I've made has been your exact words, or the words from data
sheets of battery manufacturers.

You admit that you have no experience with NiMH chargers working at
less than 0.1C, so why don't you just bow out?

And *I* misquote? I said no such thing.

Peter

 

[richardghole@yahoo.com]

Hi

The NiCd changer I have is about 15 years old and I think it takes
about 16 hours to charge up the batteries. However it warns on the
label that it is only suitable fror NiCd rechargeable batteries.

Could it still be ok for NmH batteries?

Your help is appreciated,
Regards Richard.

 

[David L. Jones]

Pete wrote:

David L. Jones wrote:

Rubbish. My post stands correct. A 0.1C 600mAh NiCd charger can be used
on a 2500mAh NiMH with no problems.

Except that that's *not* what you said - you gave no figures, and made
the general statement that any NiCd charger could be used on any NiMh cell.

The whole thread is the context!
I was implying that the NiCd charger the OP had could be used just
fine.

"You do realise that a 0.1C NiCd rate is *not* a 0.1C rate for NiMH
don't you?

A 0.1C NiCd rate *IS* a 0.1C NiMh rate, Dave. How can it not be?

*rolling eyes*
Of course it is, I never said it wasn't!
Can't you take anything in context?
I'm sorry I didn't spell it out absolutely clearly for the lowest
common denominator.

If what you really meant to say is that 0.1C for a 600mA cell is not the
same as 0.1C for a 2500mH cell, then that would be correct.

Geeze you are quick... That's why I put the second paragraph clearly
explaining what I meant. You knew exactly what I was talking about but
you wanted to play silly buggers and prove something. It made you looke
like a goose it what it did.
Just for you, I'll spell things out nice and slowly next time and try
not to rely on context.

But the
chemistry itself has no bearing on what 0.1C means, so your statement is
just plain silly.

It is not when it is taken in context and read with the paragraph after
it.

*of course* 0.1C is the same for both NiCd and NiMH or any other

Then why did you ask me (and I quote) "You do realise that a 0.1C NiCd
rate is *not* a 0.1C rate for NiMH don't you?"

I should have rephrased that better, obviously you didn't understand...

Dave, you appear to be trying to prove something. I just wish I
understood what it was.

I'm just countering your silly picky waffle and defending my original
post that the OPs NiCD charger will work just fine.

This is a *real* NiCd charger we are talking about here that charges at
0.1C rate *for a NiCd cell*. For a 600mA NiCd cell that is a 60mA
charge current. If you connect this *same charger* to a 2500mAh NiMH
cell it is no longer a 0.1C charge rate, it becomes 0.024C *for the
NiMH cell*. You know, basic math, 60mA/2500mAh, it's not that hard, try
it.

At last - you're making sense! However, to do so, you've had to start
quoting numbers rather than making silly generalisations. But when I
quote numbers, you accuse me of all sorts of things.

This is what the OP wants to know, can an old NiCd charger be used on a
new NiMH cell, the answer is yes.

The original poster said nothing about "old", that's something you
added. The original poster, as I recall, asked a general question,
without specifying anything about the charger other than that it was a
NiCd changer.

Rubbish. The OP said in his very first post:
"I do have some Nickel Cadmium battery chargers that charge slowly over
about 16 hours"
That is quite clearly a 0.1C charger for a 600mAh NiCD, and as I have
said (and you now agree), that will work just fine for a 2500mAh NiMH.

You then gave a general answer, without knowing *any* of the details of
the charger. That general answer was wrong, *because* you didn't know
any of the details.

See above.

Now you're saying that a *specific* NiCd charger in a *specific*
situation, will work. I agree.

However, we've taken a bloody long time to get here, and there's been an
awful lot of waffle, and some *bad* information that some people may
take as fact because of the way it was presented, *without* any detail.

There was perfectly good detail in my posts, it was your snipping that
removed it.
But I will try better next time to spell things out nice and clearly
without context, just for you!

The devil's in the detail, Dave - you can't generalise.

See above.

But of course you aren't contributing
to the actual thread and helping the OP, you are just being silly.

Your contribution started with a bad generalisation, then progressed to
a few more bad generalisations, some strange advice that 0.1C for NiCd
chemistry was different to 0.1C for NiMh chemistry, and other similarly
silly generalisations.

As I have said, only someone who takes it completely out of context
could take it the wrong way.

Finally, though, *because* I took you to task on that generalisation,
we've finally arrived at good advice. And that's that a specific charge
rate for a specific NiCd charger probably wouldn't damage a NiMh cell.

Fancy that, I was right all along!

That's *vastly* different to your original claim that any NiCd charger
is suitable to charge NiMh cell.

Context dear Peter, context.

Stop these stupid context and misquote games, you really are making
yourself look like a total goose.

Every quote I've made has been your exact words, or the words from data
sheets of battery manufacturers.

My exact words taken out of context by you.
Oh, and I loved your attempt at posting a datasheet. It didn't even
have anything in it about maintenance charging, and it had confusing
info about trickle charging. No wonder I assumed your claim meant that
NiMH's can't be trickle charged in any way shape or form.

After all, you did say "Trickle charging cannot be used with NiMh
batteries." Trickle charging NiMh cells *will* reduce their service
life." - that's what started all this.
What you really meant was that a 0.1C charging rate will do damage, and
I have never said it won't. Who's not expressing things clearly now?

You admit that you have no experience with NiMH chargers working at
less than 0.1C, so why don't you just bow out?

And *I* misquote? I said no such thing.

You implied it by brushing it off and saying "At least I understand
what 0.1C *means*"
I'll ask again then, do you have any experience with NiMH chargers
below 0.1C?

But I've had enough, this is silly. I'll go back to helping the OP now.

Regards
Dave

 

[David L. Jones]

richardghole@yahoo.com wrote:

I got one labeled "lenmar nomem pro" it's a fast-charger with a 12V plug
pack and a car adaptor, it'll charge 1000maH AA nicads in 100 minutes and
NiMHs in proportianately longer (and shut off automatically)

--

Bye.
Jasen


Hi Jason

Thanks for your letter.

I thought that a rapid charger could possibly damage the camera or
overheat it and that a very slow rate of charging would be best used.
Do you think so?

You are correct!

What is the output voltage and current of the charger you refer to?

Don't even think about using the fast charger Jason is referring to.
You need either
1) a slow charger (<0.1C rate, that's < 250mA for 2500mAh NiMH),
or 2) a fast NiMH charger with voltage cutoff and preferably a temp
cutoff sensor in the camera. But NiMH cells can get very hot during
charging, so this is still a risky thing to do inside your camera.

The slow 16hr NiCD charger you have will work just fine, it will just
take a long time to charge the batteries.

Use those Lithium AA's you are getting and all will be right with the
world!

Dave

 

[Pete]

David L. Jones wrote:

The whole thread is the context!
I was implying that the NiCd charger the OP had could be used just
fine.

But that's not what you said - you said that there is essentially no
difference between NiCd chargers and NiMh chargers, in your original
"answer". Go back and check.

Your back-pedalling and attempted justification and re-phrasing of what
you actually said have now finally arrived at the truth of the matter in
a certain specific circumstance, and that's what the original poster wanted.

I'm tired of correcting the errors and generalisations in what you
posted, and I give in - clearly you're right, and I'm wrong. Everyone
can see that, Dave. You win. Congratulations.

For the record, I've done a lot of work with battery powered equipment.
I've designed a number of battery chargers for a variety of
chemistries, worked with and repaired many more, and even "re-designed"
a few battery chargers in some imported equipment so that they actually
worked properly. I've seen some excellent designs, and some very poor
stuff, the poorest stuff invariably intended for NiMh cells. However,
I'm clearly out-classed in this subject by you, Dave. Good work.

Peter

 

[David L. Jones]

Pete wrote:

David L. Jones wrote:

The whole thread is the context!
I was implying that the NiCd charger the OP had could be used just
fine.

But that's not what you said - you said that there is essentially no
difference between NiCd chargers and NiMh chargers, in your original
"answer". Go back and check.

This might help:
http://dictionary.reference.com/browse/context

Also, note the word "essentially" in my sentence:
This might help too:
http://dictionary.reference.com/browse/essentially

My use of the word "essentially" means that there is more to it than
that.
Then of course there are all the other posts which explain stuff in
more detail, but you have to harp on about one particular sentence. Get
a life, really.

I could take you to task exactly the same way over your statement:
""Trickle charging cannot be used with NiMh batteries." Trickle
charging NiMh cells *will* reduce their service life."
but I won't.
You are just as guilty as me, so let it be.

Like I said, next time I'll try and rephrase things a bit clearer, just
for you!

This is my last post on the subject.

Dave

 

[richardghole@yahoo.com]

Hi

I am not sure if everyone saw my last post that may clarify things. It
is below together with another question.

The NiCd changer I have is about 15 years old and I think it takes
about 16 hours to charge up the batteries. However it warns on the
label that it is only suitable for NiCd rechargeable batteries.

Could it still be ok for NmH batteries?

If not, do you know of any NmH chargers that would be slow enough to
charge batteries inside an appliance like a camera?

Alternatively could one be made up economically?

Bear in mind the charger could be connected to a common electric timer
to turn it off frequently to prevent to fast a charge or overheating.

Your help is appreciated,
Regards Richard.

 

[APR]

Hi Dave, I think you lost that one. If we have to revert to the dictionary
to determine that in some obscure circumstances your wording may have had
the meaning you now say you meant it to have then I believe you are behind
the 8 ball. Next, we will be looking at the legal definition of words and
court determinations on word phrasing to win our discussions.

 

[jasen]

On 2006-06-21, richardghole@yahoo.com <richardghole@yahoo.com> wrote:

I got one labeled "lenmar nomem pro" it's a fast-charger with a 12V plug
pack and a car adaptor, it'll charge 1000maH AA nicads in 100 minutes and
NiMHs in proportianately longer (and shut off automatically)

Thanks for your letter.

I thought that a rapid charger could possibly damage the camera or
overheat it and that a very slow rate of charging would be best used.
Do you think so?

What is the output voltage and current of the charger you refer to?

yeah, i forgot you wanted to charge the batteries in-place

I'll stick a meter on the charger ans see what current it gives for a
"maintenance charge" after the cells are full.

Bye.
Jasen

 

[jasen]

On 2006-06-20, David L. Jones <altzone@gmail.com> wrote:

Pete wrote:
David L. Jones wrote:

Most NiCD chargers are just a constant current source (with cutoff
functions), and CC is a pefectly valid way to charge a NiMH. The life
won't be shortened at all if the OP uses a sufficiently low NiCd
trickle charger on a NiMH.

Here's a quote directly from the Panasonic web site: "Trickle charging
cannot be used with NiMh batteries."

The next paragraph says:
"However, after applying a refresh charge using a rapid charge, use a
trickle charge of 0.033CmA to 0.05CmA"
It also goes on to recommend a timer just in case.
So it's actually telling you to use a trickle charge.
The quote not to use it is most likely referring to traditional NiCd
levels. The guy who wrote it probably got a bit confused.

Take a look at the Energizer application note:
http://data.energizer.com/PDFs/nickelmetalhydride_appman.pdf
Page 19:
"For charging schemes that then rely on a timed "topping' charge to
ensure complete charge, a rate of 0.1C appears to balance adequate
charge input with minimum adverse effects in overcharge.
Finally a maintenance (or trickle) charge rate of 0.025C (C/40) is
adequate to counter self-discharge and maintain cell capacity."

and Duracell:
http://www.duracell.com/oem/Pdf/others/TECHBULL.pdf
Page 16:
"A number of applications require the use of batteries which are
maintained in a fully-charged state. This is accomplished by trickle
charging at a rate that will replace the loss in capacity due to
self-discharge. In these applications, a trickle charge at a C/300 rate
is recommended. The preferred temperature range for trickle charging is
between 10°C to 35°C (50°F to
95°F). Trickle charge may be used following any of the previously
discussed charging methods."

So Energizer and Duracell fully endorse trickle charging, just like
many other manufacturers, and just like professional charger systems
la784110> have.

So it's perfectly OK to use a trickle charge, just make sure it's very
small, smaller than for NiCd.

C/20 (Energiser) is larger than the standard (14 hour) charge rate for
a similarly (physically) sized nicad.

--

Bye.
Jasen

 

[jasen]

On 2006-06-21, richardghole@yahoo.com <richardghole@yahoo.com> wrote:

Hi

The NiCd changer I have is about 15 years old and I think it takes
about 16 hours to charge up the batteries. However it warns on the
label that it is only suitable fror NiCd rechargeable batteries.

Could it still be ok for NmH batteries?

15 yeas ago NiMh wasn't commonly available. I think the label was to
stop people from putting carbon-zinc, and alkaline cells in it.

If you figure the charge rate at 600mAh in 16 hours a 2400mAh cell is going
to take 4 times longer, so if you start it monday morning about wednesay
evening the it'll be done.

Bye.
Jasen

 

[David L. Jones]

APR wrote:

Hi Dave, I think you lost that one. If we have to revert to the dictionary
to determine that in some obscure circumstances your wording may have had
the meaning you now say you meant it to have then I believe you are behind
the 8 ball. Next, we will be looking at the legal definition of words and
court determinations on word phrasing to win our discussions.

OMG I'm guilty of generalising! Anyone know a good priest I can confess
to? :->
Is there some way I can install a "spell stopper" program to stop me
typing words like "essentially", that could be useful on here!
It's all quite good fun actually, was getting a bit dull on here :->

BTW, is it just me, or do others think the OP might be a bot of some
sort?...

Dave

 

[jasen]

On 2006-06-21, jasen <jasen@free.net.nz> wrote:

On 2006-06-21, richardghole@yahoo.com <richardghole@yahoo.com> wrote:


I got one labeled "lenmar nomem pro" it's a fast-charger with a 12V plug
pack and a car adaptor, it'll charge 1000maH AA nicads in 100 minutes and
NiMHs in proportianately longer (and shut off automatically)

Thanks for your letter.

I thought that a rapid charger could possibly damage the camera or
overheat it and that a very slow rate of charging would be best used.
Do you think so?


What is the output voltage and current of the charger you refer to?

yeah, i forgot you wanted to charge the batteries in-place

I'll stick a meter on the charger ans see what current it gives for a
"maintenance charge" after the cells are full.

20mA - seems a little high, full rate is 700mA

I'd go with the lowest charge rate quoted here C/300 - about 8mA


Bye.
Jasen

 

[Dave Goldfinch]

On 21 Jun 2006 02:58:44 -0700, "David L. Jones" <altzone@gmail.com>
wrote:

APR wrote:
Hi Dave, I think you lost that one. If we have to revert to the dictionary
to determine that in some obscure circumstances your wording may have had
the meaning you now say you meant it to have then I believe you are behind
the 8 ball. Next, we will be looking at the legal definition of words and
court determinations on word phrasing to win our discussions.

OMG I'm guilty of generalising! Anyone know a good priest I can confess
to? :-
Is there some way I can install a "spell stopper" program to stop me
typing words like "essentially", that could be useful on here!
It's all quite good fun actually, was getting a bit dull on here :-

BTW, is it just me, or do others think the OP might be a bot of some
sort?...

Dave

I was just about to suggest the same thing - no matter what you
suggest, he/it will always find some way to say that your suggestion
is impractical and then go on to ask for more !

He/it did the same with a request for a wireless data link a short
while ago until aonther poster lost patience with him.

Yet another Dave

 

[ian field]

<richardghole@yahoo.com> wrote in message
news:1150699524.690686.255390@y41g2000cwy.googlegroups.com...

Hi Dave or whoever can help,

Thanks for the reply.

With the digital camera I have it is very hard and time consuming to
open the battery case. It is a very tight fit. Also it is very easy to
forget to put the batteries in if they are taken out. Having to put
them in would take crucial time if the photograph had to be taken
urgently. For example, I plan to take weather phenomenon that can only
occur for a few seconds at times without notice.

There are some cameras that charge the batteries internally but they
are rare and may not do what I want.

On my Nickel Cadmium charger they warn that it can only be used for
Nickel Cadmium batteries.

Do you know of any suitable charger?

Regards Richard.



David L. Jones wrote:
richardghole@yahoo.com wrote:
Hi

A while back I was discussing charging batteries up inside appliances
and received a couple of responses on the thread on Tues, Mar 14 2006
at 3:34 pm. However, I am not sure what battery charger to use if
there is any available. It would have to be a slow charging rate
charger. Many digital cameras are rated at 3 volts but AA batteries are
normally 2.5 volts for 2 AA batteries. Therefore, 3 volts should be
enough to charge them and would not be too high for the camera.
However, I would have to be careful that the batteries did not get too
hot for the camera so a slow charge would be needed.

Why would you want to butcher a camera to slow charge standard AA's
inside??
Why not just take them out and sit them on a commercial trickle
charger?
Put some Alkalines in the camera in the mean time to keep the time/date
going.

Cameras that have a docking cradle will often let you recharge the
batteries in-situ. Does your camera support this?

Are there any battery charges that are suitable or would one have to be
modified? How many hours would a charger have to take so that it would
be safe?

I do have some Nickel Cadmium battery chargers that charge slowly over
about 16 hours but I heard that Nickel Metal Hydride are better for
cameras. I can't understand why Nickel Cadmium chargers cannot be
used for Nickel Metal Hydride batteries. Do you think that the Nickel
Cadmium battery chargers that I have could be easily modified to slowly
charge Nickel Metal Hydride batteries?

There is essentially no difference between the two chargers. You can
use a Nicd charger to charge NiMH's.

I heard that cameras do drain a small amount of power from the battery
even when they are switched off. Rechargeable batteries also discharge
quickly so if a camera is not used for a few months the batteries would
be flat and this would prevent the camera being used quickly.

Yes, the camera takes an almost unmeasurable amount to keep the
time/date clock going. A pair of Alkaline AA's in there will probably
last half the shelf life.

I am about to make an order from http://www.electusdistribution.com.au/
and am wondering if any of the below charges would work for this
purpose?
MB3520
MB3505.

I can't see why you want to do this, why not just take the batteries
out?
Keep them on a wall trickle charger next to the camera and simply pick
them up when you want to use the camera. A few seconds to insert them
and away you go.

Dave

Rip the charging electronics out of a wireless optical mouse charging
cradle, these usually charge 2x AAA cells so they won't overheat AA cells.
In the UK I just bought such a mouse for only Ł5.99p - it'd be a close run
thing whether you could buy the individual components for less!