Recharging alkaline batteries

Subject: Recharging alkoline bateries
From: Pied Piper
Date: 26 Feb 02 - 08:19 AM

Hi folks I've just discovered that alkoline bateries are rechargeble (they kept that well hidden). Has anyone out there tried this? Maplin in Manchester UK sell a charger that claims to do this, but it costs £30. I'd appreciate any info ta

Subject: RE: Recharging alkoline bateries
From: John J
Date: 26 Feb 02 - 09:40 AM

I'm not too sure what the charge rate is, but the basis of operation for the Maplin charger (as far as I understand) is:

AC mains is transformed down to the required voltage.

This voltage is still AC, therefore not suited to DC applications.

Normal chargers use a diode arrangement as a rectifier. This provides DC (polarised volts).

This will charge primary cells, but a much improved modification is to parallel a 1k or so resistor across the diode (assuming single diode half wave rectification).

The effect is to provide the battery or cell with a substantial positive charge pulse, the follow it up by a slight discharge pulse. This is repeated at a frequency determined my the local mains frequency, for us Mancunians it's 50 cycles per second.

Or PMe with your phone number and I'll give you a ring. I live in Timperley, work in Sale.

John

Subject: RE: Recharging alkoline bateries
From: Les from Hull
Date: 26 Feb 02 - 10:01 AM

I've got a charger that works like this and I use it all the time. They're also better for charging NiCd and NiMH cells as they completely discharge them first, which makes them last longer.

With alkalines the best trick is not to wait until they are fully discharged, but to 'top them up' regularly.

Subject: RE: Recharging alkoline bateries
From: John J
Date: 26 Feb 02 - 10:29 AM

Hull?

Subject: RE: Recharging alkoline bateries
From: Art Thieme
Date: 26 Feb 02 - 03:06 PM

Al played for Detroit.

Subject: RE: Recharging alkoline bateries
From: SeanM
Date: 26 Feb 02 - 03:15 PM

I'm against recharging the buggers. Lost a tuner because I'd not noticed that the casing was decaying - the alkaloids from the batteries leaked and ate away the contacts.

Found out later that this is normal for trying to recharge them, and that they CAN explode while doing so. Better to invest the extra couple bucks in REAL rechargeables and not worry about it.

M

Subject: RE: Recharging alkoline bateries
From: JohnInKansas
Date: 26 Feb 02 - 07:24 PM

ANY battery can, in principle, be recharged. Whether you want to try it depends mainly on your tolerance for rather nasty results.

In any battery, a chemical reaction of some sort produces a voltage. When current flows out of the battery, the continued chemical reaction maintains the voltage.

By applying a higher voltage to the battery terminals, you can make the chemical reaction "run backwards" so that whatever gets "eaten up" by the normal action is - at least partially - restored.

In most disposable primary cells, the casing for the cell is partially consumed during discharge. While recharging may partially restore the (usually metal) casing, there is no guarantee that it will be restored evenly, and even a few discharge/charge cycles will usually result in a case rupture which will leak very nasty stuff all over your fine electronic equipment.

In addition, most of the common chemical processes tend to produce gasses. Since non-rechargeable batteris are usually not vented, there is the very real possibility of an "explosion."

Batteries intended for recharging are made either with a casing so thick that it is expected to outlast any reasonable number of charge cycles, or have a separate - nonreacting - case. Some rechargeables are also vented. Common disposables have none of these features.

Even with batteries designed for recharging, there are some hazards. At least two series of Compaq portable/laptop computers, and one Apple series have been recalled because of "frequent" Lithium Battery fires/explosions. (Note that this was a battery mfg problem, and is not meant to reflect on the quality of the computers. Information is not "publicly" available on any similar problems other mfrs may have had.)

You can, in fact, "recharge" ordinary carbon/zinc and other batteries, and devices to do so have appeared occasionaly in the marketplace. The likelihood that you will destroy the equipment in which the recharged batteries are used makes it a rather dubious saving.

Recharge disposable batteries (carefully) if you want, but use them only in "disposable" equipment.

John

Subject: RE: Recharging alkoline bateries
From:
Date: 26 Feb 02 - 07:39 PM

Only SOME alkaline batteries are rechargeable. They are clearly marked. Regular ones are not. Try to recharge them, and you'll start a fire.

Subject: RE: Recharging alkoline bateries
From: Pied Piper
Date: 27 Feb 02 - 05:46 AM

Thanks every one That gives me some stuff to think about. All the best Pied Piper

Subject: Al Kaline, baseball great
From: Joe Offer
Date: 27 Feb 02 - 07:22 AM

To add to what Art said, I lived in Detroit in the 1950's, and legendary Tigers outfielder Al Kaline had friends who lived down the street. I'd often see Al's pink Cadillac parked in front of the house. Seems to me there should have been a song about Al.

Now that I'm older and more suspicious about such things, I wonder if it could have been a girlfriend who lived down the street. No, it was probably a nice, older couple he went to church with on Sundays...

I thought alkaline batteries blew up when you put them in a charger. I think I prefer baseball.

-Joe Offer, enjoying spring weather in California-

Subject: RE: Recharging alkoline bateries
From: Jon Freeman
Date: 27 Feb 02 - 07:29 AM

I had persuaded my mother to get a charger for the NiCad and NiMh batteries and to switch over to using re-chargable batteries towards the end of last year. When this thread started, I thought that I may have given her the wrong advice. Reading through though, I am convinced it was the right move - better to spend a few extra pounds on proper regargeable batteries than to run those risks!

Jon

Subject: RE: Recharging alkoline bateries
From: John J
Date: 27 Feb 02 - 07:42 AM

I would agree with all the comments regarding the lack of suitability / reliability of recharging primary (non-rechargeable cells & batteries).

One attraction of primary alkaline cells is that they are generally of a much higher capacity than 'proper' rechargeables, although I have no idea of the capacity of a recharged primary.

If a primary cell is to be recharged it's perhaps a good idea to limit the number of recharge cycles.

John

Subject: RE: Recharging alkoline bateries
From: Jon Freeman
Date: 27 Feb 02 - 07:49 AM

John, I have found that rechargebles will not work in the flash for my camera. I take it that is related to the capacity issue you mentioned.

Jon

Subject: RE: Recharging alkoline bateries
From: Les from Hull
Date: 27 Feb 02 - 08:56 AM

Well, I'll say again that I have been recharging 'non-rechargable batteries for yonks, and I've had no problems whatsoever. As John says they have a much greater capacity than rechargables and so are much better when you're away from the mains.

I only buy good quality batteries. I think you're much more likely to get accidents with cheaper ones.

The number of recharges you get depends on how far you run them down. A torch (flashlight) will run a battery down to nothing, whereas my pda needs a certain current to work. So I can start the batteries in my pda and finish them off in a torch or bike light or tv remote.

But you do need the proper sort of charger. Don't but non-rechargeable batteries in a regular charger.

Subject: RE: Recharging alkoline bateries
From: JohnInKansas
Date: 27 Feb 02 - 01:52 PM

Jon Freeman

A fresh carbon/zinc primary battery has an "open circuit" voltage of 1.54 volts.

A fully charged NiCad rechargeable normally has an open circuit voltage of about 1.3 volts.

If your flash uses a typical 4 AA cells, the disposable batteries will feed it 6.16 volts when new, while a set of fully charged 4 NiCads will only show it 5.2 volts.

The lower voltage of the rechargeables is enough to prevent some devices from working with NiCad rechargeables.

There are other rechargeables that you can try if the common NiCads don't work in your device, but it can get pretty expensive doing it by trial and error.

A good camera shop might be able to advise you.

John

Subject: RE: Recharging alkoline bateries
From: Jon Freeman
Date: 27 Feb 02 - 05:16 PM

Thanks for the info John. I don't think I'll worry about getting rechargables for the flash as it doesn't get a lot of use and the batteries seem to last well with my usage.

Jon

Subject: RE: Recharging alkoline bateries
From: Hrothgar
Date: 28 Feb 02 - 05:54 AM

It's easier than spelling them.

Subject: RE: Recharging alkoline bateries
From: MikeofNorthumbria
Date: 28 Feb 02 - 10:40 AM

Here's another rechargable alkaline battery problem – has anyone else suffered from it?

At first my new portable minidisk recorder worked like a dream. But then, I tried recording with it after not having used it for several weeks. Disaster - all the recordings were overlaid with hisses and crackles. I tried changing one factor after another with no success, and then, just as I was about to give up, the sound suddenly became clear as a bell.

A couple of weeks later, the same trouble began again. Finally, in desperation, I tried removing the rechargable battery, wiping the terminals, and then putting it back in. The extraneous noise vanished at once.

On re-examining the leaflet that came with the appliance, I found a note about battery care which I'd skipped before, thinking – wrongly - that I already knew how to take care of batteries! The note warns that if you don't intend to use the recorder "for any length of time" (it's no more specific than that) you should remove the rechargable alkaline battery from the recorder and store it in the case provided.

The only reason given in the manual is that the battery gradually runs down, even when the recorder is switched off. However, it seems plausible to me that during this slow leakage, there is a build-up of static somewhere in the works. So, when you try recording later on, the static generates these disconcerting background noises until it's eventually discharged. After which the recording quality returns to normal.

The manual say that the internal battery, when fully charged, should run the recorder for at least 6 hours (exact time depends on mode of use). Mine now lasts about half an hour before giving up. Conclusion - leaving it inside the box for months, as I foolishly did, is bad for your battery's health. Be warned! A new battery costs about £20: if you can find a shop near you that stocks them. (I haven't, yet.)

At present the recorder still runs satisfactorily - at home with the AC transformer, and away from home using an external AA dry battery in the bolt-on holder provided with the kit. However, neither of these options will work without the internal battery (which I presume serves as some kind of buffer). So, when my rechargable battery eventually dies, the system will be jiggered until I can get a new one.

The expert at the most useful shop I tried yesterday said one of these batteries should stand 500-1000 recharges before giving up. But he added that occasional intermittent use would shorten its life considerably. And, as I have now established, leaving it in the machine to discharge slowly through the works will kill it off even faster, besides spoiling a lot of recordings.

Moral - be kind to your battery! Don't forget to let it out of jail at the end of a recording session.

Wassail!

Subject: RE: Recharging alkoline bateries
From: John J
Date: 28 Feb 02 - 11:25 AM

Mike, let me know the details of the battery. I may be able to help. eg: Type number. Include, if you can, a sketch with dimensions, voltage, capacity, type of battery (eg Lithium Ion / Nicad, etc), and any identifying numbers / letter on the battery case.

John

Subject: RE: Recharging alkoline bateries
From: JohnInKansas
Date: 28 Feb 02 - 11:38 AM

An additional reason for removing the batteries from any device that will not be used for a while - as long as there is a battery in the device, there is a voltage present that can "accelerate" the corrosion of the battery contacts (and anything else nearby).

The process is similar to "electroplating" except that you "plate" the battery contacts with whatever crud happens to be in the air.

Most of the corrosive products that are likely to accumulate in this way are not particularly good conductors. The result is that when you "pull" current, the voltage seen by the equipment drops - even though the battery itself may be fully charged. This could be the cause of the "static." The current pulled by the recorder varies with what it's doing, and the voltage varies (probably non-linearly) with the current draw.

If the crud isn't too bad, wiping the terminals may suffice. If it gets bad enough to penetrate the terminal plating, you can expect to have continual problems with erratic voltage to the device.

If the capacity of a rechargeable is significantly reduced, it is sometimes possible to restore it somewhat by "reforming." This usually involves a complete discharge and recharge cycle. With "battery packs" containing multiple cells, however, this may be difficult. Unless each of the individual (internal) cells can be brought to zero charge at the same time reforming doesn't work very well.

If your electronics supplier can't get you a replacement, you might find something suitable from a cell-phone shop(?), although you'll probably need to do your own matching of specs.

John John

Subject: RE: Recharging alkoline bateries
From: Penny S.
Date: 28 Feb 02 - 06:28 PM

This is all very interesting. I have been recycling non-recyclables in a purpose designed recharger for some years without any dire results. However, the charger won't work on completely discharged batteries, and the batteries don't then last as long in power hungry devices. I use them in clocks and the door bell and other such things except in emergency.

I regret not having a proper means of disposal in the end.

Penny

Subject: RE: Recharging alkoline bateries
From: Mickey191
Date: 28 Feb 02 - 06:44 PM

Can anyone answer this? From various tools,which have ceased to function, I've a collection of rechargers. Can they be safely used on other tools which have the same amps? The charger for my Toro weed wacker is lost. I've an old one from a nail gun. They always say it's a no-no. Is it??

Subject: RE: Recharging alkoline bateries
From: JohnInKansas
Date: 28 Feb 02 - 07:07 PM

Mickey191

The battery packs for different tools can be quite a bit different internally, so it's almost impossible to give a general answer on this.

It should be noted though, that it's generally the voltage of the battery that determines whether a given "foreign" charger might work.

Using anything other than a charger designed for a given battery may not give you the best battery life - in terms of number of recharge cycles. Charging rate (the amps) can affect how well the battery "takes" the charge.

There is also the possibility of overheating the battery if you use a high-capacity charger on too small a battery.

NiCad batteries, used in most such tools, are relatively "forgiving" and it's reasonably likely that you could use some other charger with fair results. Some of the newer tools have gone to NiMH or even Lithium rechargeables, and these are much more sensitive to "nonstandard" charging - even though they generally give much better performance when treated properly.

The recommendation would be that you scout around for a replacement for your Toro charger. It shouldn't be that hard to find, or even terribly expensive.

The only possible, direct answer to your question is "maybe." A more detailed answer would be "maybe yes and maybe no."

John

Subject: RE: Recharging alkoline batteries
From: Mickey191
Date: 01 Mar 02 - 01:20 AM

Thank you John, appreciate your help. Mickey

Subject: RE: Recharging alkoline batteries
From: MikeofNorthumbria
Date: 01 Mar 02 - 06:50 AM

John J - thanks for the offer of help. See your personal page for my PM with battery details.

JohninKansas - thanks for the technical details. Every bit of information helps.

And everyone else - don't forget to gird up your alkaloins before recording.

Wassail!