Normal Alkaline batteries can be recharged !

[pese]

Can you post a schematic for an alkaline battery recharger?


I have a whole box full of dead AA batteries.

use the normal -?pw cost- charger that aur to use for 1,2volts NiCad / or Metalloxyd batteries.
But they are not stabilised to overcharging volts Voltages.

The BiCad rechargable batteries stop to charge at approx 1,45 volts. And will not destroy the battery
with some hours overcharge.


BUT the charger will spend 4 to 5 volts in maximum (without loading batteries  connected !
So this is cause that alcalien bateries and also RAY-O-VAC specieal Alkaline rechargable batteries will destroy in this cahrgers BECAUSE they are  sensetive to OVERLOAD (in voltages).
They charge from 1,5 volts beginning even up to 2,2  2,5 and higher voltages, BUT they go hot will explode or leacking.

With 3 time 1N4007 (each have 0,7volt Vf)
sot the Voltage can stabilised at aprox 2volts (without batterie in Charger
If connected (between positive and negative pol )(att.: to polarity).

Attention all chargeable batteries  (any type) will be loaded with maximum 20% over the normal voltages !
1,2volt wit 1,44 volts
12 volts with 14,4  (example als lead acid  , enz)
1,5 volts at 1,8volts   enz.

so the alcaline are charged it the voltage arrived 1,8 volts.
to "shild them with 2volt diodes" is an protection for the battery,
if you have not the time to "observe" the charge.
Without this protection , alcalin batteries will die within 1 - 2 hours overloading with more than 2 volts

Have fun with this.
Recharge alltime before batteries are fully empty !!

Pese

[Feynman]

Okay, so no schematic...

I think you are telling me to apply a reverse bias voltage at less than 2V ?     Is it better if the voltage is continuous or pulsed?  If pulsed, is there a proper frequency.  Thank you for the information, I am sure this will be very useful.  I save all my dead batteries, because I figured there would come a day when we could figure out how to recharge them all.

[Tink]

Okay, so no schematic...

I think you are telling me to apply a reverse bias voltage at less than 2V ?     Is it better if the voltage is continuous or pulsed?  If pulsed, is there a proper frequency.  Thank you for the information, I am sure this will be very useful.  I save all my dead batteries, because I figured there would come a day when we could figure out how to recharge them all.

Is this site of any help?:
http://www.i-hacked.com/content/view/207/44/

[Feynman]

Thank you;   very much so.

I used the same 63mA current source to charge a pair of dead alkaline AA batteries in series. Since AAs have higher capacity than a 9v, it took all day to fully recharge them.
I discharged them at a current of 330mA for hours, and they still hadn't gone flat. I said screw calculating capacity and decided to call it a fully charged success.
Destructive testing: After two full days of charging the AAs eventually popped open making a fizz noise, and leaked 3 drops of weak acid that was easily cleaned up with my bare hands. The experience was about as life threatening as a squirrel urinating on my lawn. The final measured voltage that killed it was 2.0V, which doesn't surprise me. Charging a 1.5V battery past 1.8V is kinda dumb.

http://www.afrotechmods.com/reallycheap/batteries/batts.htm


Looks like you can do full alkaline AA recharge if you use 63mA and less than 1.8V.  I am going to build this too, I have all the parts.

Summary
You can fully recharge a depleted 9v alkaline battery at 63mA overnight without problems. You can fully recharge a depleted alkaline AA battery all day without problems. I recharged both types of batteries twice, and I would expect them to easily take many more charges. If you care about safety more than I do, attach a multimeter to the batteries and monitor them so they never reach more than 110% of their rated voltage.

[pese]

Hello,
your circuit is an CURRENT - Source (Limiter)
you must limit the Voltage.

youur cahrging alkaline must in the way from emiter to ground.

the diodes D1- x must chousen so that no nore than
1,8 to 2 volts can be cahrges to the alcaline cell.
The load current , can be limeted with an resistor (or Pot) tgat come between Collector and + suppli.
(in the wy , kow your cicuit shown the batterie now.

If need i will do an circuit by main , and scan this for this thead ,
i think its understanding now.

Pese