Hi,

I want to build a overcharge protection circuit for my 12v battery charger.
When the threshold voltage is reached, charging should be stopped.
Any help appreciated.
Please tell me as simple as possible

 

Use a comparator circuit with a 555 chip, or op amp....

 

Or a LM339 comparator....

 

Better yet, get a battery manager IC appropriate for your battery chemistry. Something like this, maybe. (There are many others.)

 

View attachment 116869

Hi,

I want to build a overcharge protection circuit for my 12v battery charger.
When the threshold voltage is reached, charging should be stopped.
Any help appreciated.
Please tell me as simple as possible

What are you using now? Can you modify that?
A voltage comparator monitoring the output of the battery, set for 13.8 V (Lead Acid type battery?). The output clears a latch that turns off power to the charger. Or maybe just cuts it down to a trickle charge.
How is your electronics? Can you build something if given a schematic?

Just a starting point ...
(image updated for design error)
Still not actually built yet, just a starting proposal.

 

Actually one of the simplest and most widely used solutions is a LM317 circuit, adjusted to the targeted trickle voltage. Charging never really completely ceases, but it gets very small as the target is reached.