Thread: Recycling batteries

Interesting.

Why don't you just wire in an old DC powerpack of the correct (or similar) voltage and do away with batteries forever?

The wattage won't matter as transistor radios don't require much.

Volts can be + or - 10% without any problems.

That's what I did.

Rob

Hi Rob,

That's fine wiring my tranny in, but I like to take it from room to room, so to speak.

Ken

Not to put too fine a point on it but these batteries are not being recharged, to do that the batteries needs to undergo a reversible chemical reactions which is not possible given the chemicals present in an alkaline battery. What putting them in a recharger does is slightly heat them so that it partially clears the hydrogen gas that builds up around the central electrode. Not that I advise it but a similar effect can be achieved by putting them in an oven on low heat for several hours. The recharger works better because the heat is generated at the electrode where the gas is present whereas the oven heat needs to get in through the guts of the battery..

Dry cell batteries have heaps of energy in them even when they are dead flat. The problems is the energy cannot get out because the hydrogen raises the internal resistance of the battery which eventually stops the current flowing through the battery.

Just a reminder that's hydrogen gas that is being heated, it's not usually enough volume to be really dangerous but depending on how quickly they are heated there is still a good chance that the battery could split and make a mess. The level of danger depends on the number of times the batteries are heated and the battery charger some which use higher currents than others may explode the batteries.

It will be interesting to see how many "revitalisations" you can get out of them.

Thanks Bobl, I like your technical explanation, I'll let everyone know how long these batteries last, just for the record.

Ken

Hi, I have a Rezap Battery Doctor charger that happily charges alkaline batteries. Some of the cheap alkaline batteries will recharge three or four times without problems. The thing that you have to watch out for is the battery leaking after it has been charged - the Duracell Copper Top ones are the worst for this that I have found as they will often leak into your clock/radio etc after the first recharge. It's probably the gas pressure inside the battery building up like BobL said that causes some to leak a bit prematurely, but you can still save a heap on these batteries by recharging them a few times. The Rezap charger is a "smart" charger (sold as capable of safely recharging alkaline batteries) and it will let you know when the battery wont take a recharge as well as an indication of the power left in the battery. It would take quite a few battery recharges to pay back the cost of the charger though.

If all else fails, get yourself one of those dynamo powered radios. I have one to take camping and all you have to do is wind the handle for a minute or so occasionally to keep it going - no batteries required! - but you will have to wind it a fair few times to get 20 hours worth of listening

Simon

When I was a kid, batteries seemed to be so much more expensive (or so it seemed) and they only ever had the carbon zinc batteries that were crap. When I had a toy that needed new batteries, I would tell mum, she would then give them to Dad and he would sit them above the furnace heater for half the night and then give them back to me. It used to "recharge" them and everyone was happy again!

Now I know the science behind it all. Thanks Bob!

Simon

You don't like rechargeable batteries? Like this one:
bat2.jpg

or cheaper this one? :
bat.jpg

Ren

I'll throw in my 2 cents. We use rechargable AA's at work for 2 way radios. The best by far are the Sanyo Eneloop based on how much charge you get out of them after all the idiots have finished trying to recharge then etc. They are the only one they buy now.

I picked up 2 Rezap chargers for $10 each couple of years ago. I tried the alkalines in them but gave up. Not worth the effort.

The problem I have is that I use a small mp3 player plugged into an old cheap stereo for music in my shed. This mp3 player takes 1 only AAA and it does not last 24 hrs. I could make up a fake battery with just the connections to connect to a charger pak but 1.5v?

Dean

Originally Posted by Oldneweng

I'll throw in my 2 cents. We use rechargable AA's at work for 2 way radios. The best by far are the Sanyo Eneloop based on how much charge you get out of them after all the idiots have finished trying to recharge then etc. They are the only one they buy now.

I picked up 2 Rezap chargers for $10 each couple of years ago. I tried the alkalines in them but gave up. Not worth the effort.

The problem I have is that I use a small mp3 player plugged into an old cheap stereo for music in my shed. This mp3 player takes 1 only AAA and it does not last 24 hrs. I could make up a fake battery with just the connections to connect to a charger pak but 1.5v?

Dean

You would have to drop the voltage down using an adjustable voltage regulator or, if it has a USB port then fed it 5V from a USB charger?

Simon

Originally Posted by simonl

You would have to drop the voltage down using an adjustable voltage regulator or, if it has a USB port then fed it 5V from a USB charger?

Simon

It has a mini usb but will not take power from there. Because it is powered from a replacable battery it wont do so as there would be no reason to. I prefer replacable batteries in this situation as when the battery goes flat you can just put in a new one. I have used another mp3 player with usb power to run it from a power pack but this does not make it portable which is one of my requirements, sort of. Maybe I should just buy a new mp3 player that does what I need. They are dirt cheap. I prefer ones with sd card sockets actually so you can change on the run.

My other mp3 player has a micro sd socket. I think they should make them even smaller (sd cards). This would make it even easier to lable them with the contained content.

I have an adjustable voltage power pak but I think it only goes down to 3v. Parallel wire a battery compartment to take multiple bigger rechargable batteries? Get one of those BIG 1.5v batteries!

Dean

Originally Posted by BobL

Not to put too fine a point on it but these batteries are not being recharged, to do that the batteries needs to undergo a reversible chemical reactions which is not possible given the chemicals present in an alkaline battery. What putting them in a recharger does is slightly heat them so that it partially clears the hydrogen gas that builds up around the central electrode. Not that I advise it but a similar effect can be achieved by putting them in an oven on low heat for several hours. The recharger works better because the heat is generated at the electrode where the gas is present whereas the oven heat needs to get in through the guts of the battery..

Dry cell batteries have heaps of energy in them even when they are dead flat. The problems is the energy cannot get out because the hydrogen raises the internal resistance of the battery which eventually stops the current flowing through the battery.

Just a reminder that's hydrogen gas that is being heated, it's not usually enough volume to be really dangerous but depending on how quickly they are heated there is still a good chance that the battery could split and make a mess. The level of danger depends on the number of times the batteries are heated and the battery charger some which use higher currents than others may explode the batteries.

It will be interesting to see how many "revitalisations" you can get out of them.

Truly rechargeable alkaline batteries (with reversible chemical reaction) do exist. some info here:
Rechargeable alkaline battery - Wikipedia, the free encyclopedia

Originally Posted by cba_melbourne

Truly rechargeable alkaline batteries (with reversible chemical reaction) do exist. some info here:
Rechargeable alkaline battery - Wikipedia, the free encyclopedia

Good point, I forgot about those.

Originally Posted by BobL

Not to put too fine a point on it but these batteries are not being recharged, to do that the batteries needs to undergo a reversible chemical reactions which is not possible given the chemicals present in an alkaline battery. What putting them in a recharger does is slightly heat them so that it partially clears the hydrogen gas that builds up around the central electrode. Not that I advise it but a similar effect can be achieved by putting them in an oven on low heat for several hours. The recharger works better because the heat is generated at the electrode where the gas is present whereas the oven heat needs to get in through the guts of the battery..

Dry cell batteries have heaps of energy in them even when they are dead flat. The problems is the energy cannot get out because the hydrogen raises the internal resistance of the battery which eventually stops the current flowing through the battery.

Just a reminder that's hydrogen gas that is being heated, it's not usually enough volume to be really dangerous but depending on how quickly they are heated there is still a good chance that the battery could split and make a mess. The level of danger depends on the number of times the batteries are heated and the battery charger some which use higher currents than others may explode the batteries.

It will be interesting to see how many "revitalisations" you can get out of them.

And all my Dad told me was "more free electrons find their way to the poles". At school i remember all the kids talking about putting batteries in the freezer to "recharge" them. I kept telling them just to leave them out and the same thing would happen, and that they were not really being recharged. Who's gonna listen to the class nerd though?
Thanks for taking the time to explain Bob.

Ew

Hi, please take precautions when experimenting with charging primary cells. Keep an eye on them while they are being charged. High charging rates can cause explosions if the internal vents fail. Fire do happens only when they are overheated.

Few of the con's apart from safety reason is leaking batteries. The alkaline juice will attack battery terminals on your device quickly. Then it travels into the connecting wires corroding the tin and copper. The alkaline will eventually land on the circuit board attacking the copper tracks via capillary action. This is time action based and corrosion happens very quickly and it is irreversible damage. Early attacks can be saved, severe corrosion requires more work.

Battery leaks happens by various unexplained reasons. Recharging alkalines will increase the risk.

Since you already own a charger, get a set of Sanyo Eneloops. They are now bought over by Panasonic brand change might happen. These batteries will be happy to eat and supply at any time you like. If your charger is a human controlled time based charger, don't over charge them and you will be able to milk hundreds of cycles out of them. They are Low Self Discharge so they will work even though they have been inactive for a few months.