Nickel-Cadmium Rechargeable batteries anyone?

Hey all, so I've got some weird Nc batteries which are basically 3 D cell batteries sealed in a tube with this info: "SEALED Rechargeable batteries, 3,6v 1500mAh. NI-Cd"

I'm wondering, since I have about 2-3 of these, (the hyphen will be explained later) is it a good idea to try and use these? Or are they so old and useless that I would be better off just buying lithium ion batteries?

Apparently they've worked before guaranteed but one of them has since had its seal broken (hence, the mentioning of 2-3 and not just 3) . like a tiny crack on the plastic part around the 3 cells connected in parallel. I read online that the electrolytes could leak out but I'm not sure if it's from the batteries themselves or just anywhere in the seal since I'm not too fond of batteries yet. But that's the whole reason I'm asking this, a little learning experience at the least, or some new usable batteries for future projects in the future.

Now if you are someone reading this who already knows these batteries aren't worth the time I'd really appreciate if you just skipped the rest of this post and tell me to throw them away. Otherwise I'll never really find out until it's too late. Thanks.

Now for charging them? I don't have a fancy shmancy battery charger with adjustable voltage and digital compliments. I want to make one my own, just because.

I have 3 wall chargers with varying outputs I'll list here.

  1. Note: warning on the thing says; polarity restricted. Designed for use with DSL or DSi only.
    it also has two prongs, they both look like variants of the usb family.
    Output: 5.2V 450mAh Second output: 5V 600mAh

  2. Output: 12V 1.25mAh

  3. Output: 5V 700mAh (my guess is this is the best option)

I'm looking to cut one of these open and slap them onto a breadboard with resistors and such, but can't decide which is best to convert. I tried looking online but there isn't much info about these types of batteries.

Anyways thanks to all those who read this far at least. Hope someone can help me out with this fun little project. And have a great day!

If you can solder, you can go with one of these

Velleman K7300 NiCd Battery Charger

(available elsewhere for less, but this link was convenient)

adwsystems:
If you can solder, you can go with one of these

Velleman K7300 NiCd Battery Charger

(available elsewhere for less, but this link was convenient)

Yeah that looks cool and all and surely seems like it would do what I want. But then again, it would be more fun to try and make one myself. That thing DOES require a solder and I do have one but right now I'd prefer to go the other route.
But thanks nevertheless for the offer, I had no idea that existed and will keep it on my wishlist for later

The Battery University website has lots of info about charging the different types of battery.

...R

NiCads can be charged with a current limited source where the a current no more than C/10, that is, one tenth the battery capacity (something like 5000 mAh for a D sized NiCad, so <500 mAh). One of your 5 V sources and a 10 Ohm resistor would do this. (Edited to add) Note that this works for individual cells or cells in series (what you’ve described); cells in parallel should not be charged this way. “Smart chargers” use a more sophisticated algorithm and will result in longer battery life, but this gives you a simple test to see if the cells are any good.

NiCads that have been sitting around for years without being charged tend to develop internal shorts, so it’s likely at least some cells are going to be bad.

Cadmium is considered a toxic/hazardous material so discarded batteries should be disposed of according to the regulations of your community. In the US the major hardware and electronics retailers (e.g. Lowes, Home Depot, Best Buy) accept such things.

MrMark:
NiCads can be charged with a current limited source where the a current no more than C/10, that is, one tenth the battery capacity (something like 5000 mAh for a D sized NiCad, so <500 mAh). One of your 5 V sources and a 10 Ohm resistor would do this. (Edited to add) Note that this works for individual cells or cells in series (what you’ve described); cells in parallel should not be charged this way. “Smart chargers” use a more sophisticated algorithm and will result in longer battery life, but this gives you a simple test to see if the cells are any good.

NiCads that have been sitting around for years without being charged tend to develop internal shorts, so it’s likely at least some cells are going to be bad.

Cadmium is considered a toxic/hazardous material so discarded batteries should be disposed of according to the regulations of your community. In the US the major hardware and electronics retailers (e.g. Lowes, Home Depot, Best Buy) accept such things.

Oh wow that was exactly what I was looking for! I will try that out later tonight thank you very much for such an amazing answer!

NiCd batteries are charged in very much the same way as the more modern NiMH rechargeables that are everywhere these days...so not really anything very exotic. And they may be o.k. I'm still using NiCds that are almost 20 years old.

If yours say they are 1500mAh then they should ideally be charged at 1/10 of that, so 150mA. At that rate a full charge takes about 15 hours.

Your "chargers" really supply a bit too much current but should be o.k. provided you don't leave the battery on charge for than an hour or so initially. If you have a DMM check the voltage before you start the charge and after the hour. It may be zero initially, that's o.k. but you're aiming for something around 4.2V when it's fully charged.

Steve

Robin2:
The Battery University website has lots of info about charging the different types of battery.

...R

Yeah I read there too and I still have the tab open, it just didn't make sense to me that much but thankfully MrMark just explained it perfectly so now I think I'm set.

Hi.
By your discription i believe the battery packs you have are three cells (of 1.2 volts each) wired in SERIES no PARALLEL as if they were in parallel they would only be 1.2 volts.
The batteries are wired and then coated in heatshrink that protects the wires and holds them togeather so the CRACK may only be the outer heatshrink cover not the actual batteries.

BEWARE when batteries have been sitting uncharged for a long time it is possable for one of the three cells to go flatter than the others. This can be a problem unless the charger is a very very good one.

Lets think of the batteries as water tanks, you have three tanks that you must fill full of water and you run a hose from your tap to each of the tanks.
When you turn the tap on to fill the tank you can only fill them so fast or the pressure builds and a tank goes boom. (Thats the current limiting)
There is a sensor on the tap that checks the preasure and when it goes up to high (as it would when the tank fully fills) it turns the tank off but this can only monitors the preasure of all three tanks at the same time so when the first one fills it turns off even if the others are not full.
This can happen when one tank has a slow leak and the others dont.

When you use the water in the tanks there is a sensor that stops the drain when the first tank empties meaning you only get the capacity of the lowest tank.

The down side to having tanks in series.

The way to fix this is to fill each tank individualy or to put in a system that will allow water to trickle in at a preasure that will not explode the other tanks but will eventualy fill all the tanks.

If you dont believe the EXPLODING bit just try charging the batteries with no cutout.

The good chargers will monitor Voltage, Current and temperature of the battery pack and cut or modify the charge based on info from those sensors.

I would measure the voltage on the battery packs and see if they are at 3 volts or more. If not beware.

You will need a certain voltage to be able to charge the batteries and at a fixed current.

Daz1712:
Hi.
By your discription i believe the battery packs you have are three cells (of 1.2 volts each) wired in SERIES no PARALLEL as if they were in parallel they would only be 1.2 volts.
The batteries are wired and then coated in heatshrink that protects the wires and holds them togeather so the CRACK may only be the outer heatshrink cover not the actual batteries.

BEWARE when batteries have been sitting uncharged for a long time it is possable for one of the three cells to go flatter than the others. This can be a problem unless the charger is a very very good one.

Lets think of the batteries as water tanks, you have three tanks that you must fill full of water and you run a hose from your tap to each of the tanks.
When you turn the tap on to fill the tank you can only fill them so fast or the pressure builds and a tank goes boom. (Thats the current limiting)
There is a sensor on the tap that checks the preasure and when it goes up to high (as it would when the tank fully fills) it turns the tank off but this can only monitors the preasure of all three tanks at the same time so when the first one fills it turns off even if the others are not full.
This can happen when one tank has a slow leak and the others dont.

When you use the water in the tanks there is a sensor that stops the drain when the first tank empties meaning you only get the capacity of the lowest tank.

The down side to having tanks in series.

The way to fix this is to fill each tank individualy or to put in a system that will allow water to trickle in at a preasure that will not explode the other tanks but will eventualy fill all the tanks.

If you dont believe the EXPLODING bit just try charging the batteries with no cutout.

The good chargers will monitor Voltage, Current and temperature of the battery pack and cut or modify the charge based on info from those sensors.

I would measure the voltage on the battery packs and see if they are at 3 volts or more. If not beware.

You will need a certain voltage to be able to charge the batteries and at a fixed current.

Oh perfect, yeah I thought the crack didn't mean much but the big all caps sealed label ticked me off a bit so I just had to be sure. Thanks for clearing it up.

Alright and now I understand with your water tank explanation that I have to be really careful with charging them too fast, thanks for that. I think I should probably get a more professional battery charger haha, but this is still just a little experiment with nothing to lose so I'll see.

In my experience, 10y old nicd batteries are likely to be deader than doornails...

westfw:
In my experience, 10y old nicd batteries are likely to be deader than doornails...

I'm still running some AR500s I bought in 1997. They are a little bit down on capacity. I also have plenty of sub-C NiCds from around that era that still work fairly well.

I've seen plenty of dead ones over the years too. You can't tell until you test them. Some NiCds were as tough as old boots.

Steve

Experiment away, off the shelf is easy but no good if your not near a store.
Have seen people stuck with the simplest of problems due to lack of basic experience.
Its not like you are going to scream if one ends up dead because it cost you a fortune.

Nicads were one of the most rugged littie buggers around. I remember some of the original fast chargers (down to 30 min for a full charge) causing me to play "Hot Potato" with them but they still worked.

if you have the stuff to charge them, the price is right.
if you have to buy stuff, compare that to the cost of replacing them with new stuff.

money is often not a big concern, but if you buy stuff that in weeks or months is obsolete, you will be buying the Li batteries with chargers anyway.

NiCd rc batteries are charged in very much the same way as the more modern NiMH rechargeables that are everywhere these days...so not really anything very exotic. And they may be o.k. I'm still using NiCds that are almost 20 years old.

If yours say they are 1500mAh then they should ideally be charged at 1/10 of that, so 150mA. At that rate a full charge takes about 15 hours.