A silly chem question?

[gizz72]

Hi everyone,
 I'm wondering, after a year or 2 those Ni-Cad batteries don't least very long, specially on those mobile cell, pc and such....
 So what is better,(though i'm no chemist) but which rechargable cell type should exceed more than a year of life, Metal Hydride(correct spelling?) or Nickel Cadnium battery? Or if you guys know a better mixture, fire away! I'm all eyes!

Thanks

Good day to all Amigans! :-D

[iamaboringperson]

I think, of those two, Nickel Metal Hydride(sp?? ) is the better one.

[gizz72]

I think, of those two, Nickel Metal Hydride(sp?? ) is the better one.

 :-?  :-P  :lol:  :-D

[KennyR]

Nickel-Cadmium (Ni-Cd) has a very slight advantage over Nickel Metal Hydroxide (Ni-MH). NiCd last just that bit longer, are less heavy, cope better with heat conditions dicharging them, and last just that bit longer. But it's very close. Most people will never see a difference.

NiCd have a memory condition which means if you try to charge 'em when they're not fully flat, they don't charge very well. Intelligent chargers or intelligent users can get around this. But since most people have neither (:-P), NiMH is starting to replace NiCd.

And to answer your question - they have about the same lifetime, NiCd having a little more. NiMH will live better if you're an impulsive charger. NiCd will live better if you like to leave things alone, or if you live in a hot place (which you might).

[Cymric]

While I always presumed that NiMH batteries were superior to NiCd ones in charge and discharge properties (less memory effect, higher power densities and higher currents) I think the main reason people are switching is because of the extreme toxicity of Cd. It is contained, true, but people don't always properly dispose of these batteries.

Which brings up an interesting question: many industries today obtain Cd as a highly undesired by-product. Especially fertilizer plants produce quite a lot of it. There is no way to get rid of it: everything containing Cd has been slowly converting to other chemicals. So it makes me wonder a little what they are doing with the metal these days.

[gizz72]

@KennyR
I see. Gee, thanks for the (hot) answers. :-) I appreciate it.
Last question, tell me, any new tech/breakthrough's on this field which would least more than expected? Two years at most?

Thanks again.

Good day to all Amigans! :-D

[gizz72]

@Cymric
OMG, you're right. Don't want that in the environment too. All I know is they get to be recycled. But not properly, unfortunatly, being practiced here. Just thinking the number of mobile products produced today can impact the environment tremedously.
How can you dispose of it properly? Any good suggestions(say you don't live near a recycling plant)?

[KennyR]

@gizz72

The batteries on the market today are probably the best you'll get for now. They don't last long. :/

There are other types of battery you could use - Lithium ion, for instance. Lithium holds more charge than NiCd/NiMH, but doesn't like high loads - best for very low power stuff, that needs to last ages. Mercuric oxide is even more like this. There's the old favourite, lead acid, too - but that's not really suitable for small things. And there will eventually be fuel cells - which will last hundreds of times longer than any battery. You might have to wait some years for those though..

Nice chart of battery types - here.

@cymric

Virtually all cadmium ends up in landfill. Sad but true.

And the NiCd vs NiMH argument is as old as the internet. :-D Real truth is probably one is neither better than the other taken as a whole, apart from Cd being toxic (not that Ni isn't, though...)

[gizz72]

@KennyR
Thanks for the link. Too bad I'd might as well bury it along with other batteries i disposed of. :-(
Thanks again.. :-D

Good day to all Amigans! :-D