Can non-rechargeable batteries be recharged?

[bulgin]

Hello All

A friend was here the other day and the subject of small batteries came up when I was busy changing the mouse batteries (no, not the Duracell Bunny's).

Anyway, this friend can usually be relied on not to talk rubbish and he asked me if I knew that one could re-charge small batteries marked NON-RECHARGEABLE'
.

I obviously have never tried it as I'm heeding the warning 'MAY EXPLODE OR LEAK IF RE-CHARGED'.

Well, I'm in a bit of a fix tonight. Both garagedoors' remotes' batteries are flat and the shops are shut.

The battery fitted to the remote is a Super Alkaline 23A?? 12V battery.

I have 2 regulated powersupplies here and can easily dial-up 12V but I'm worried I'll zonk the remote. The door-opener has a manual release but because a special lever is fitted to enable the doors to open to a certain height, this facility is very difficult to operate.

Any ideas, guys? Can't leave my car outside as prowlers are around.

bulgin

[forr]

There were articles in some magazines : possible but with a lot of caution. It needs special chargers. Not to do in a hurry wih régulated power supplies.

[bulgin]

Thanks forr

It's 23.45pm here in Cape Town and I guess I've got a long night sitting in my car outside with a dachshund for company.

Regards

bulgin

[gmphadte]

The older type (don't know exactly, some Mn...) could be charged,
I saw the russians on a ship charge and recharge them with ordinary power supply
but never attempt to charge the alkalines

Gajanan Phadte

[Pano]

I recharged alkalines several times (by misake) in a NiMH charger. It worked Then one cell popped and killed the charger.

[joe carrow]

I've heard that alkalines can be charged several times- but they could explode at any time during charge. Whenever I heard that, I also heard that they take progressively less charge each time you do it. Not really worth it, in my opinion.

[phase_accurate]

I wouldn't call this recharging - regenerating would be a better description.
It works best if they are only partially discharged like down to 70%. It doesn't work as good as charging an accu but you can stretch the lifespan of alkalines significantly.
And yes it should be done only with small cells as a professor of the Swiss Federal Polytechnic institute once suggested. I assume that the main rasons for this are: If they burst the damage is smaller with smaller cells and they are less likely to burst from the beginning because they have a better volume-to-surface ratio and thus better heat transfer to the environment.

This is the web - page of the aforementioned professor but in German only unfortunately:

http://www2.ife.ee.ethz.ch/~zinniker/batak/index.html

Regards

Charles

P.S.: Bulgin might have to get a new battery or sleep in his car for another night. In which part of Cape Town are you living BTW ?

[poynton]

I have often put non-rechargeable cells in a charger and also zapped cells with a car battery...

BUT...

Only for a few seconds at a time!!!

This is usually enough to get whatever it was working for the required time.

This has been with zinc/carbon, lithium and alcaline.

Andy


PS..my local store sells chargers .............

[richie00boy]

Yes you can recharge non-rechargeables, but it doesn't work very well if they are less than about half full. The technique is called periodic current reversal, and is basically an AC waveform. It's also a slow time method.

[phase_accurate]

There were articles in Elektor and EW+WW describing circuits to do this.
Yes, they did indeed suggest alternating charge- and discharge- pulses.

Regards

Charles