Charge non-rechargeable Alkaline batteries

Thread Starter

ilias

Joined Dec 10, 2011
4
Hi everyone
I will show you a method to charge alkaline batteries first, I thought that limiting the current of recharging the batteries did the trick, but no! The electrolyte leaks from the end of the negative terminal, when the battery leaks, it loses in the best case 50% of its capacity. so another method is needed!!!
The technique of a discontinuous contact: thanks to this technique the battery could suffer much less stress when recharging but on condition of leaving the battery two times longer to rest than to recharge (2 seconds of 6) 2s charging, 4s resting, And it works! Batteries recharged without problems!
Weather when recharging AA, AAA or 9 volt, no problem it works and it does not leak. In the worst case we can always limit the intensity.




The circuit consists of a simple oscillator that charges the batteries for 2 seconds and stop for 4 seconds.
The oscillator drives the Mosfet that charges the batteries.
Choose any mosfet Type, and any small transistor, that handle the charging current, if you want to charge a lot of batteries choose a high current transistors.
Another transistor and a potentiometer control the charging current, to charge all types (AAA AA 9V):
I recommend:
• AA: maximum 250mA
• AAA: 110mA max.
• 9V: 70mA max.



To recharge the batteries you must inject a voltage greater than the batteries voltage by X1.5.
This charger can charge as many batteries as you want! with 12 volts can be up to 6 (with more than 12 volts but in this case consider increasing the value of some resistors).
To make sure that your batteries are full charged and not damaging them, monitor their voltage, it should not exceed 110%, for example: a battery of 1.5V, maximum charge voltage is 1.65V.
(considering regeneration 80%), a 2Ah battery needs 20h for a complete recharge, Long? not really if you're not pressed.

Notes
Before charging the batteries try to select them: never take that are not alkaline, leaking already, which are rusty, which are of a mark "cheap", that give "0.00 volts" or supposed to be "outdated "for too long. Remember that alkaline batteries can be recycled. no saline lithium or any non alkaline battery it won't work and it's dangerous.

The source post: http://easy-electronics4u.blogspot.com


any questions
Thanks
 

Wendy

Joined Mar 24, 2008
22,138
IMO this is not a safe project, given that alkaline tend to explode when recharged. All it would take is one user doing something different. However, I've brought it to the attention of the other moderator, and we are discussing it. We'll get back with you.
 

Thread Starter

ilias

Joined Dec 10, 2011
4
the charging current is low so ,the worst thing that can happen is that the overcharged battery leaks, the voltage should be mesured for not exceeding 110% of nominal voltage.
 

bountyhunter

Joined Sep 7, 2009
2,512
If you think standard alkalines are rechargeable, I've got a slightly used bridge I will sell you.

This circuit is nothing but a current pulser.
 
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Wendy

Joined Mar 24, 2008
22,138
I had several Alkaline rechargers during the 90's. They work, after a fashion. It is one reason I decided to let the thread stand. It is worth trying, I suspect some batteries take it better than others, though I never got close to 80%.
 

bountyhunter

Joined Sep 7, 2009
2,512
When I was an NSC back in the 90's, we worked with the company who "brought out" rechargeable alks and chargers for them, I think it was eveready (?) but couldn't swear to that, it might have been another maker.

When I saw the performance data and specs I swear I thought the product line was a complete JOKE:

1) The "advantage" of alkalines is the higher A-hr capacity.

2) however..... "rechargeable" alks lose their rechargeable capacity if they are deeply discharged...... so you can't use their A-hr capacity if you want them to remain rechargeable.

They recommend only shallow cycling followed by immediate recharge.

Are you kidding me?

I told my people this product was crap and we didn't waste any time on it. We all saw how well the public took to it..... Fry's had them on the shelves for a couple of months then they disappeared never to be heard from again from that maker.


I guess the "new" ones still do:

The discharge time and capacity of RECHARGEABLE ALKALINE cells decreases or fades with increasing number of discharge/charge cycles under deep discharge conditions (that is, when all of the capacity is removed in each and every cycle). RECHARGEABLE ALKALINE works best in medium and lower drain applications.
 
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Wendy

Joined Mar 24, 2008
22,138
The project is not against Tos, it isn't overunity or other, and to a very small extent, it occasionally works. It passes muster, in other words.

Having been posted, it is up for public comment however. A form of peer review.
 

Wendy

Joined Mar 24, 2008
22,138
I am sitting in my underwear while I type this. I could send them to you if you'd like.

To the OP: You do good presentations. I think you need to step back and look at your designs a bit. Try to look at them as we would, seeing them for the first time, and identify the perceived flaws ahead of time.
 
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