NICD battery charger

[Constructionk88]

Hello fellow steady handed friends! Alrighty I have quite a few NICD battery packs and Ive decided i want to start using them. I just started trying to charge them using a well underrated AC adapter( 3x1300mha 4.8v batteries /w/ 6.3v 240mah adapter). oddly it seems to be working and i know not why. I wanted to build a charger for it but im not sure where to begin. I cant find a circuit compatible with this and id like to build one. Any suggestions?

 

[KeepItSimpleStupid]

Ditch them and upgrade to Ni-mH. Look at OPUS or a charger. The one I use doesn;t do packs.

I used to discharge the Ni-Cd's fully through a resistor. Measure the voltage. Charge a big cao to about 30V and discharge it into the Ni-Cd to remove shorts

lately, I've upgraded to Ni-mH. Basically, a drop in replacement.

 

[Constructionk88]

Appreciated though i should add that these were all free and when i say a "few" i mean to say ohhh around 40+ 3cell-6cell packs. All from, not old, emergency lights. Thats why id like to use them. I have so many so when they eventually cycle out ill have many to replace them.

 

[audioguru]

I gave up using Ni-Cads 25 years ago because they developed short circuits. I switched to Ni-MH and LIthium POlymer.

 

[Musicmanager]

Hi K88

Welcome to ETO .. .. . ..

I've attached a schematic for a pair of battery chargers designed and built by me ( with a modicum of help from others) to charge my cordless drill batteries which was completed some months ago and is now in regular and reliable service. The circuit would need some 'tweaking' for your purpose but nothing that couldn't be quite easily done.

The circuit is Arduino controlled, isolated from the charging circuit and incorporates a digital ammeter which displays the charge taken in use.

This may be a useful place to start .. .. .. .

S

 

[Constructionk88]

Thanks Musicmanager. I'll give it a go. audioguru wouldn't newer nicd batteries be somewhat more reliable? The oldest probably isn't over a few years. They work fine and I can charge them, just not safely overnight as is recommended.

 

[audioguru]

audioguru wouldn't newer nicd batteries be somewhat more reliable? The oldest probably isn't over a few years. They work fine and I can charge them, just not safely overnight as is recommended.

Ni-Cad batteries are old and are obsolete. Cadmium in Ni-Cad batteries is deadly and is now banned in many countries. Major battery manufacturers do not make Ni-Cad batteries anymore. Ni-MH has replaced them with a much higher capacity and longer shelf life.

 

[Musicmanager]

Cadmium in Ni-Cad batteries is deadly and is now banned in many countries.

The ban refers to sale of new batteries, not the use of existing equipment.
However, I've no wish to get into any kind of a debate .. .. .. the choice is down to the OP in my opinion and to that extent I've offered some help.

S

 

[audioguru]

"The use of existing equipment"!
I smell and am poisoned by antique cars driving around. They should be banned. Home fireplaces that burn smokey wood should also be banned.

 

[Musicmanager]

I smell .. .. .. .

There's a one liner there but I'll refrain in the interest of a good relationship !


Do antique cars or home fireplaces use NiCd batteries then ?

I entirely take your point AG, but if the guy has a boxful of useful batteries - why shouldn't he use them. I have a total of 6 cordless drills of different sizes, all of which use either NiCd or NiMH batteries. I couldn't justify the expense of replacing them all just to satisfy your quest to rid the world of anything that doesn't have LiPO up it's backend. Of course, I will have to eventually, but by then, and I'm sure you'll agree, I may well have turned my toes up.

S

 

[rjenkinsgb]

if the guy has a boxful of useful batteries - why shouldn't he use them.

Exactly!

They are far better doing something useful, as long as they can, than going to a landfill (or some dubious "recycler" that dumps most of the constituents in a landfill anyway).

Delaying that by a few years may mean recycling is better at scavenging the harmful materials.

 

[DrG]

I think that getting rid of the Cadmium is a good Idea - I am for that. Regarding the OP's issue, however, I could not find any information that using a NiCd places any cadmium into the environment (ok, I didn't spend a lot of time looking). My point is that a much greater concern than using some NiCds that he already has is that he properly disposes of them, when the time comes to dispose of them.

In the US, you can search for a local disposal facility here.

In Canada, you can search for a local disposal facility here.

 

[Musicmanager]

My point is that a much greater concern than using some NiCds that he already has is that he properly disposes of them, when the time comes to dispose of them.

Absolutely right .. ..

There are numerous local disposal facilities in the UK too. Indeed, many of the larger supermarkets, Tescos, Asda & the like offer a FOC battery recycling 'bin' in store, so it isn't difficult.

S

 

[shortbus=]

when the time comes to dispose of them.

He can send them to Canada, in care of audioguru.

 

[Constructionk88]

Eh when the time comes ill dispose of properly, and that mostly is my point. why waste all that i have when they have years and potentially hundreds of cycles left in them? As i said they arent old. we still install the models i salvaged but they cant be used again once removed. We upgraded a large school with the fancy glass refractive ones. I have more than 40(it was an estimate). I just cant find much information on charging other than 10% of capacity, which i understand....but i dont understand is that 10% voltage as well or should it be equal Vin to Vout and 10%capacity? Thats what i cant seem to find. I can charge the individual cells just fine. I have a 20cell NICD, NIMH charging bank that charges from AAA-D. Just dont want to dismantle already convenient battery packs ya know.