Talk:Nickel–cadmium battery

Environmental aspects

Ok, I believe everything I added in my revision to be factual, but I did most of this research for a paper I wrote for chemistry class three years ago. There are a couple of things which I'm not sure haven't changed since then, hence "as of 2000". Things to be improved include the comparison to other types of batteries (perhaps a general comparison of batteries deserves its own article) and it could use some external links. CyborgTosser 00:25, 14 May 2004 (UTC)

I think the environmental aspect should me mentioned more. In many markets NiCd cells are phased out for this reason. 217.210.121.213 02:10, 14 Jan 2005 (UTC)

Well, given that this is Wikipedia, you know what to do :) ! Gather the facts, organize them into a neutral point of view, and have at it! (And I certainly agree that cadmium is a serious environmental neurotoxin, worthy of attentyion here; that's certainly a big part of the reason behind the shift to NiMH cells.)

Atlant 16:58, 14 Jan 2005 (UTC)

Well I could sure use some more help knowing the enviormental aspects of the batteries. 71.226.121.41 21:31, 3 January 2006 (UTC) JCP

Merge

We could treat common features to all nickel-cadmium batteries in common sections in the article and differences in nickel-cadmium type´s specific sections (one for vented, other for sealed).

Or we could fix the mess this article has become rather then add more bloat to it. The article on vented cells is there because vented cells are very different from sealed cells. Trying to merge them while dealing with the differences would make this article even longer and confusing. --Miikka Raninen 06:39, 2 June 2007 (UTC)

Since no further discussion has been forthcoming on this subject for some time, I'm removing the merge-tags from these pages. --Miikka Raninen 07:31, 24 October 2007 (UTC)

Emergency lighting

I'm not aware of NiCd batteries being used in emergency lighting. All the wall-mounted emergency lights I've seen in the U.S. use maintenance-free gelled electrolyte lead-acid batteries. I'm not sure why; it may be required by fire codes. It may also be due to the nasty tendency of NiCd batteries to grow dendrites and short themselves out, which could lead to tragedy in the case of emergency lighting in public buildings. --Quicksilver^{T @} 23:44, 18 November 2005 (UTC)

• I also believe that in some emergencies, some people may not have the time to discharge the Ni-CD battery before recharging it. (unsigned comment from anon)

Comparison to other batteries

Could we add a comparison to Lithium Ion batteries? I know there's already a little blurb in the article mentioning Li-Ion, but it's short and in another section. Eptin

Possible trademark infringement

NICAD is a trademark of SAFT America Inc., Valdosta, GA, for nickel cadmium products. It should not be used as a generic short name for these batteries. —The preceding unsigned comment was added by Lnthomp (talk • contribs) .

ITYWF that the trademark is actually owned by the main French Parent company SAFT.

I B Wright 11:34, 13 December 2006 (UTC)

A little grammar problem

I'm not an expert on batteries and don't feel I can do the correction, but the following sentence is ungrammatical and confusing: "Safety Procedures: Never short circuit the battery. By dropping, hitting or denting the battery does damage that is often irreparable"

PERHAPS the intended meaning is "Never short circuit the battery. Dropping, hitting, or denting the battery does damage that is often irreparable." This, however, fails to explain HOW one could short circuit the battery.

Someone knowledgeable should do the re-write.

—The preceding unsigned comment was added by 70.242.139.138 (talk • contribs) .

Done -- see what you think now.

Atlant 14:15, 19 July 2006 (UTC)

Wh/Kg NiCd

Something seems wrong. The table says that the energy density of NiCd Batteries is 30 Wh/Kg. Too low, it is the same as lead batteries. In various sites, I find 40-60 Wh/kg or 45-80 Wh Kg. Can someone check this point?

What are the Wh/kg values for dry versus wet NiCd. I know that the NiCd AA cells (which are very light and probably dry or nearly dry) are much lighter than Alkaline or NiMh AA cells. jtankers 18:47, 25 February 2007

Sanyo spec for "dry" cells:

• 1/3 AA, 110 mAh, 7 g = 16 Wh/Kg
• C, 3000 mAh, 84 g = 36 Wh/Kg
• D, 5000 mAh, 150 g = 33 Wh/Kg

Also many cells are available in different capacities, large "wet" cells, as used for starting batteries probably have completely different values. Suckindiesel 02:00, 26 February 2007 (UTC)

Please ignore above figures, which in fact are Ah/Kg.
On the basis that Watts = Volts x Amps, then Ah/Kg x cell voltage = Wh/Kg, therefore:

• 1/3 AA, 110 mAh, 7 g = 16 Wh/Kg x 1.2 = 19 Wh/Kg
• C, 3000 mAh, 84 g = 36 Wh/Kg x 1.2 = 43 Wh/Kg
• D, 5000 mAh, 150 g = 33 Wh/Kg x 1.2 = 40 Wh/Kg

By comparison, large industrial "wet" cells yield different results:

• SAFT, 1.2-V cell, rail, 435 Ah, 27.7 Kg. Equivalent to 19 Wh/Kg
  
• SAFT, 24-V battery, Airbus, 50 Ah, 42 Kg. Equivalent to 29 Wh/Kg
  

Suckindiesel 20:28, 26 February 2007 (UTC)

Cleanup

I'm going to attempt to clean up the article, at least the sections tagged for cleanup. My chemistry is a bit rusty, so I'm starting from the assumption that the facts and figures are correct as stated, and I'm not intentionally going to change any of them. Someone with more recent experience should probably double-check me. Kutulu 18:19, 24 January 2007 (UTC)

Reads like manufacturer's promotional literature for NiCads

This article strikes me as badly dated and strongly biased towards nickel-cadmium batteries.

There is no discussion of one of the problems caused by the virtually flat discharge curve -- cell reversal in a multi-cell pack.

I have never experienced the "memory" effect. However, my understanding is that it first showed up with the introduction of rechargeable toothbrushes. (I remember their introduction -- I'm 60.) After a single short use, the toothbrush was returned to its charger. After a while, the batteries would no longer provide full service. Some owners discovered that, if the toothbrush were turned on for an extended interval (this usually occurred by accident, when the toothbrush was accidentally turned on by jostling in a suitcase) -- well past the point where it stopped working -- full capacity would be restored.

GrizzledGeezer 12:38, 13 March 2007 (UTC)

With regared to cell reversal, please feel free to be bold and add information regarding that. And if you feel you can improve the WP:NPOV aspects of the article, have at that, too!

Atlant 13:16, 13 March 2007 (UTC)

Done! added most common problems: overcharge and cell reversal

--Miikka Raninen 21:08, 9 April 2007 (UTC) PS: Oops, another of my IP edits : 84.250.76.65 :P

Nominal voltage of 1.2v

I often see NiCad batteries on the shelves at stores with labeled 1.25v (or multiples of 1.25v) next to NiMH batteries with labeled 1.2v (or multiples of 1.2v). Is the 1.25v designation just marketing or is the nominal voltage of NiCad cells actually a little higher than that of NiMH cells? Hal(unregistered)192.88.165.35 15:14, 21 March 2007(UTC)

To be technically accurate, the official voltage of a nickel-cadmium cell is 1.24 volts. 86.141.194.60 17:46, 15 July 2007 (UTC)

Ultimate lifetime of AA NiCd vs. NiMH batteries

One of the fastest growing consumer applications of NiCd batteries is in solar-powered lawn accent lights. Are NiMH batteries not used because of higher initial cost? Which would be most likely to last longer in the typical solar-light charge-all-day/discharge-until-dead routine? —The preceding unsigned comment was added by 64.30.203.214 (talk) 22:39, 30 March 2007 (UTC).

It seems that solar powered lawn lights in the US (mostly made in China) use NiCd batteries to save a few pennies in materials cost and because there is not enough regulation or consumer awareness to avoid this environmentally-inappropriate technology. This is certainly not a high-current-drain use that would benefit from the special advantages of NiCd. Are these products restricted or prohibited in Europe?-69.87.199.58 (talk) 14:27, 28 September 2008 (UTC)

They are now! lawn lights are not one of the exempted uses. 20.133.0.13 (talk) 13:47, 28 October 2008 (UTC)

Continuous charging

Can one indicate the effects of permanent recharging of rechargeable batteries (ie. when a cordless phone is in the recharge base all the time). --Nopetro 20:32, 21 May 2007 (UTC)

In general, continuous recharging damages rechargeable batteries. The extent of damage depends on the amount of current the charger continues to apply. Cheap dumb chargers will apply a very unhealthy level, nearly as much as when actually charging the battery. Smart inexpensive chargers will switch to a slow trickle charge based on time or sensing the battery charge level. Smart fancy expensive chargers will continuously monitor the battery charge state, and apply an occasional pulse of charge current, just enough to maintain a full charge.

Unless you are sure that you have a smart gentle charger, it would be better for the batteries to mostly not leave them in the charger after they are charged. But that would be much more trouble for you, and may leave you with half-charged batteries when you need them. A compromise might be to put the charger on a timer, say set to be on for an hour per day. Experiment until it is on just enough to keep the batteries charged over the long-term.-69.87.199.58 (talk) 14:27, 28 September 2008 (UTC)

Deleted Sony ENG discussion

I deleted this recent addition:

One point overlooked is the fact that Sony ENG (Electronic News Gathering) equipment that operated from "12V" NiCd batteries had a low voltage cutout that turned the device off at 10.8V This insured that Sony ENG gear would always discharge the NiCd battery to the same voltage level. Sony ENG was very rough on NiCd batteries and battery life was always much less then the 800-1000 charge/discharge cycle life that is often quoted. 400 charge/discharge cycles was the norm. Sony has switched to Lithium-Ion and this is no longer a concern.

because I don't think it is very encyclopedic (why 'one point overlooked'?) It also looks like original research ((WP:OR). Han-Kwang (t) 07:20, 13 January 2008 (UTC)

Internal resistance

What is the internal resistance of various types of batteries?

AA cells are the most comparable between technologies. Sanyo AA NiCd are rated at 16-19 milliohms (.016-.019 ohms).[1]

There are 40 actual NiMH AA discharge data sets here.[2] Looking at the middle of the 1 Amp and 2 Amp discharge curves, the difference is generally about .05 V (about 1.20 down to 1.15 volts); the lowest are about .03 V. This implies that the effective total differential internal resistance of NiMH AA under load in the middle of discharge is about 50 milliohm (.05 ohm). -69.87.199.58 (talk) 14:53, 28 September 2008 (UTC)

Sanyo AA NiMH are rated at 25 milliohms (.025 ohms).[3] -69.87.200.234 (talk) 02:00, 30 September 2008 (UTC)

Comparison of self-discharge rates of various types of cells

"The table below shows the approximate amount of time that it takes to lose 10% of the cell's current charge capacity at different temperatures.Clint Turner KA7OEI 20070105

Cell Type	0C (32F)	20C (68F)	40C (104F)	60C (140F)
Alkaline	>15 yrs.	4 yrs.	18 mo.	3 mo.
NiCd	3 mo.	1 mo.	14 days	5 days
NiMH	1 mo.	10 days	5 days	1-2 days
Zinc Chloride	6 yrs.	2 yrs.	10-12 mo.	2-3 mo.
Li-Ion	--	1-12 mo.	--	--
Lithium-Fe-S	>20 yrs.	>20 yrs.	4 yrs.	1-2 yrs.
Lithium-Mg-O	>15 yrs.	10 yrs.	3 yrs.	1-2 yrs

These are typical values for new cells, published by various manufacturers. Note that aging/mistreated cells will probably exhibit much higher self-discharge rates."

We should have a table like this in each of the battery articles. -69.87.199.211 (talk) 12:26, 30 September 2008 (UTC)

White powder - cell leakage

I would like to add some words regarding the white powder (presumably potassium hydroxide)that can leak out of faulty cells. Any suggestions to which section this can be added? Also the contents of the fully charged cell I assume the electrolyte is potassium hydroxide dissolved in water. John a s (talk) 18:39, 22 June 2009 (UTC)

Move

Nickel-cadmium battery → Nickel-cadmium electrochemical cell — The electrochemical battery is simply a pair of electrochemical cells. this article deals around how this type of cell works. —Preceding unsigned comment added by 81.245.90.148 (talk • contribs) 12:06, 9 October 2009

• Oppose. The present name of the article is clear, common, and accurate. The proposed name is jargon found only ina chemistry lecture. Do not rename the article. --Wtshymanski (talk) 14:37, 9 October 2009 (UTC)
• Oppose, this is at the common name and should remain. ~~ GB fan ~~ ^talk 15:20, 9 October 2009 (UTC)
• Strong Oppose and suggest speedy close (is that possible?). This is not what the general public would be looking for. HumphreyW (talk) 15:25, 9 October 2009 (UTC)
• Opppose WP:COMMONNAME 76.66.197.30 (talk) 16:11, 9 October 2009 (UTC)
• Oppose The term "battery" is almost always used by consumers, battery manufacturers, etc. TJ Spyke 17:29, 9 October 2009 (UTC)