Charging batteries inside an appliance

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?

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

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.

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.

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

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

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 :)

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.

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.

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.

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.

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.

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.

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.

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

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

Peter

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.

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

*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.

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.

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

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

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

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.

See above.

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!

See above.

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

Fancy that, I was right all along!

Context dear Peter, context.

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 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 :)

You are correct!

Don't even think about using the fast charger Jason is referring to. You need either

1) a slow charger (

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

This might help:

Also, note the word "essentially" in my sentence: This might help too:

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 :)

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.

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.

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

la784110> have.

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

--

Bye.
   Jasen

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

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 :)

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

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

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 £5.99p - it'd be a close run thing whether you could buy the individual components for less!