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how to make usb-powered AA battery charger? Answered

i want to make a AA battery charger powered by usb

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steveastrouk

Best Answer 7 years ago

On the end marked "current limited output"

Steve

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steveastroukDELETED_messam

Answer 7 years ago

The negative connection comes straight from the USB port to the battery.

Steve

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steveastrouk

7 years ago

Take a look at the "related" links on the right of the page.

Steve

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steveastroukDELETED_messam

Answer 7 years ago

How does this
https://www.instructables.com/id/Simple-USB-Altoids-AA-Charger/

not meet your stated requirements ?

Steve

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top.boysteveastrouk

Answer 7 years ago

sorry there is an error in facebook connecting , i'm messam the author

the only thing is that he made it with ready battery charger
i want to make it alone

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steveastrouktop.boy

Answer 7 years ago

If you're charging Nimh batteries, then a simple constant current charger will work fine. Here's a circuit based on an LM317 you can easily adapt for the maximum charging current - I'd aim for no more than 50mA, to protect the batteries from overheating when they are fully charged.

Steve

LED driver.JPG