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Alkaline Charger Answered

So, I want to try and build a charger for alkaline batteries with an Arduino. 
I'll be using it to recharge 9v batteries.
What I want to know is:

What would the optimum charge current/voltage be? 
Should I pulse the charge current?
How do I detect the state of charge?
How can I get ~1.6v from the arduino to charge an AA? Can I use PWM 5v?
And any other useful info you may want to add.

I have a ton of parts/shields/etc for arduino as well as components. 
LCD's, IC's, LEDs, diodes, resistors, crystals, etc.

Would also like to do a battery diagnostic utility to test health, resistance, charge, etc.
Can anyone help?

EDIT: So I made a quick circuit and sketch to charge an AA battery to 1.6v, using an LM317 adjustable voltage regulator. As os so far, it is working. 

Now I need to figure out how to make a voltage doubler. I'm thinking something like 40-50 mA output at 10v.
I have an LM324N quad op amp chip as well as one of these. How could I make a doubler circuit?

7 Replies

masterleo (author)2014-10-24

I saw a Video on youtube from 'incroyables experience" chanel who did this project !
and here on


you can learn how charge Alkaline COMMON batteries SO,
we may use low current 10 mA and 1,5 V an a pause during 30 % of the time

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Orngrimm (author)2013-02-23

I once also tryed that... Was a terrible mess... If they didnt got warm, they leaked... Acid or something alike... Stained my container (Metal) quite fast...

Best thing i was able to achieve was to top up the battery a bit if i used it some time... Lets say from 60% full a charge to maybe 70%... But recharge a dead battery to full: Nope. Or at least in my long trys i wasnt able to do that.

Whats the method of charge? CC? CV? Pulsating? Intermittent pulse with relieve-discharge?
How do you want to sense if the battery doesnt accept more chatge? DeltaU? I-sens with trigger?

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LiquidLightning (author)Orngrimm2013-02-28

I charged up some batteries and finished with this project lol. I used an LM317 adjustable voltage regulator with a series resistor for a 60mA charge current, and used an Arduino to monitor and terminate the charge. So CC/CV. Arduino just checked if the voltage was at the alkaline full voltage, I think it was 1.55v and it would terminate the charge.

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OH, and I used a transistor switch to pulse the charge current at 150Hz.

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mpilchfamily (author)2013-02-20

Are you trying to recharge regular alkaline batteries or ones that are actually made to be rechargeable?

If your looking to charge the non-rechargable kind then stop right there. While you may be able to get some to charge, most will overheat and burst open on you. It's really not worth the trouble.

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The batteries will be in an enclosed container with a thermal fuse to prevent overheating.

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steveastrouk (author)2013-02-20

What has your detailed research so far yielded you ?

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