NiMh & NiCd charging

[6pOriginal]

Hi,
I am wondering what's the difference between NiMh & NiCd charging. There's a switch on my charger to switch between the 2 and I am just wondering if there's any difference.

 

[zmoz]

Well...one's for NiMh, the other is for NiCd. /ubbthreads/images/graemlins/smile.gif I think they charge the same...the difference is how it determines when the battery is full.

 

[dw_1984]

Just to clarify for other members of the board, which charger do you have?

To the best of my knowledge, zmoz's description is right. Nicads and Nimhs give off different characteristics when the battery is full and your charger must determine what type is being charged (either through a switch like yours or automatically).

Daniel

 

[6pOriginal]

I have an old AA/AAA charger from a brand called "Super" that I bought in Hong Kong couple years ago, it will automatically detect Nicd or Nimh. I also have a RC battery pack charger from Radio Shack that has the switch for that.

The reason I asked is that I also have a solar AA charger, I've used it to charge Nicd before and know that it will work with it, but I have no idea if it will work with Nicd or not, since it didn't say anything about it.

 

[dw_1984]

[ QUOTE ]
6pOriginal said:
The reason I asked is that I also have a solar AA charger, I've used it to charge Nicd before and know that it will work with it, but I have no idea if it will work with Nicd or not, since it didn't say anything about it.

[/ QUOTE ]

Which one do you mean? /ubbthreads/images/graemlins/confused.gif

I think that if there's a switch specifically for charging the different types of cells than it should be okay but don't quote me on that.

Can anyone confirm/deny whether it is okay to use a nimh charger with nicads but not vice versa? I remember I read that somewhere, or is it the other way around?

Daniel

 

[6pOriginal]

I was talking about the solar AA charger that I am not sure if it can charge Nimh or not....sorry for the confusion /ubbthreads/images/graemlins/blush.gif and thanks for the help

 

[star882]

I have a 2 hour Ni-MH/Ni-Cd battery charger that advertises to be "computer controlled".
My friend Caitlin Williams says that the "computer" is just a microcontroller.
"I think they charge the same...the difference is how it determines when the battery is full."
Well, my charger charges both Ni-Cds and Ni-MHs in 2 hours, Ni-MHs store much more energy than Ni-Cds, so the charger must provide more current for Ni-MHs(it's "computer control" can detect what type is inserted).

 

[Floating Spots]

I may be wrong (it does happen sometimes)..
The DeltaV on NiMh is much less pronounced than with NiCad.
This, its safe to charge NiCad in a NiMh charger (may be undercharged). The other way charges the CR*P out of a NiMh.
I know there is another difference (but I can't make it up right now) . /ubbthreads/images/graemlins/rolleyes.gif

 

[zmoz]

It might work to charge nicd in a nimh charger...but unless it is an emergency I wouldn't suggest it. There is a reason manufacturers put a switch on the charger. /ubbthreads/images/graemlins/wink.gif

 

[UK Owl]

There may be problems if you have a simple (no delta v detect) charger where the switch simply selects current, by charging NiCd cells at the current for NiMh cells you could quite easily overcharge them.

As for the solar charger, I have one I use to charge 4 AA cells I use in a modded reading torch, this is not the ideal as NiCd's (what I use it for) do not like to get a charge in dribs-and-drabs whereas NiMh cells can be simply topped up at any time.

p.s. Solar chargers are handy to keep a set of cells fully charged in your bedroom window, but are not up to much for everyday charging, taking 2 or 3 days of bright sunlight (we rarely get this in the UK) to fully charge 4 NiMh cells.

 

[6pOriginal]

I use my solar charger mainly as a "secondary", since I don't have a garage, and I have to park my car out on the street, I don't want to "waste" the energy so I put the charger on top of the dash board. Another reason is that I live in quake country, I figured that this may good for emergency use (may be I am over prepared /ubbthreads/images/graemlins/rolleyes.gif). It takes almost forever to charge the batteries, but it does an ok job charging my NiCads.

 

[Empath]

Edit: Original text removed as unneeded

Thanks, 6pOriginal. /ubbthreads/images/graemlins/thumbsup.gif

 

[6pOriginal]

Sorry about that, I just got rid of it...thought it was ok since it's under 30kb

 

[Bullzeyebill]

6pOriginal, for what use are you using the batteries you charger. Just wondering. Bill

 

[6pOriginal]

I have an old 2AA light that is part of my emergency kit, most of the stuff that I use run on AAA batteries, I have a book light that runs on 4AA batteries, but I use an ac adapter with it so I don't use AA batteries too often. But it may change later, after I recieve the luxeons and finish the mods /ubbthreads/images/graemlins/grin.gif